Factors associated with pregnant women's willingness to receive maternal pertussis vaccination in Guizhou Province, China: An exploratory cross-sectional study

The rise in pertussis incidence among infants in Guizhou, China underscores the need for maternal acellular pertussis vaccine (aP) immunization, a key strategy in protecting infants from severe health consequences. However, the willingness of pregnant women in Guizhou to receive this vaccine is not well-understood. This study aimed to explore pregnant women's intentions toward maternal pertussis vaccination in Guizhou and identify the associated factors. A questionnaire based on the health belief model, was administered in an exploratory cross-sectional study from January to February 2022. Data from 564 participants were collected and analyzed. The chi-square test, Mann-Whitney U test, and Poisson regression were used to identify potential factors associated with vaccination intentions. Participants' median age was 27 y (interquartile range (IQR): 24-31), and the median number of children per participant was one. The study found that only 36.0% of the participants intended to receive the aP vaccine while 64.0% were uncertain or negative in this regard. Significant factors associated with intentions to vaccinate included perceived barriers and cues for action and perceived benefits. The major barriers for low vaccination intentions were safety concerns for both the fetus and the mother, and family members' negative attitudes. Free vaccines, perceiving preventive benefits, observing other pregnant women getting vaccinated, and healthcare provider recommendations may facilitate vaccination intentions. Multiple immune strategies should be developed or optimized to cope with the resurgence of pertussis.

Vaccine coverage among children born to immigrant parents in Norway, 2000-2020

BACKGROUND

The Norwegian Childhood Immunization Program maintains a high national coverage of 95-97% in the most recent years. Whether there are subgroups with lower uptake is less studied. This study examines pertussis and measles vaccination coverage among six immigrant groups in Norway. These vaccines are normally administered as part of different combination vaccines and their coverage rate indicate the national vaccination coverage against a range of additional infections.

METHODS

Data from the Norwegian National Population Register were linked at individual level with vaccination data from the Norwegian Immunisation Registry. The final sample consisted of 53,052 children born during 2000-2018 in Norway to parents who were born in Iraq, Lithuania, Pakistan, Poland, Somalia, or Vietnam. Vaccination coverage was measured at 2-years of age. Multivariate linear regression was utilized to estimate the relationship between vaccinations status, year of birth, gender, mother's length of residency in Norway, and area of residence.

RESULTS

At two years of age, the majority of the children were vaccinated. Coverage among the groups varied at, above, and below the national average for the two vaccines. For most of the years examined, children born by parents from Lithuania, Poland, and Somalia had lower coverage for the measles vaccine (range 81-84% in 2020) than the national level (97% in 2020). Children born by parents from the Eastern-European countries also had lower coverage than the national level for the pertussis vaccine (range 87-89% in 2020).

DISCUSSION

This study illustrates how subgroups with lower vaccination coverage may exists within a well-established vaccination program with high national coverages. Differences in coverage were found for both vaccines, but the differences were more pronounced for the measles vaccine. The high vaccination coverage in Norway provides indirect protection through herd immunity for unvaccinated individuals, however, the lower vaccination coverage in some immigrant groups is a concern.

Effectiveness of one and two doses of acellular pertussis vaccines against laboratory-confirmed pertussis requiring hospitalisation in infants: Results of the PERTINENT sentinel surveillance system in six EU/EEA countries, December 2015 - December 2019

BACKGROUND

Monitoring effectiveness of pertussis vaccines is necessary to adapt vaccination strategies. PERTINENT, Pertussis in Infants European Network, is an active sentinel surveillance system implemented in 35 hospitals across six EU/EEA countries. We aim to measure pertussis vaccines effectiveness (VE) by dose against hospitalisation in infants aged <1 year.

METHODS

From December 2015 to December 2019, participating hospitals recruited all infants with pertussis-like symptoms. Cases were vaccine-eligible infants testing positive for Bordetella pertussis by PCR or culture; controls were those testing negative to all Bordetella spp. For each vaccine dose, we defined an infant as vaccinated if she/he received the corresponding dose >14 days before symptoms. Unvaccinated were those who did not receive any dose. We calculated (one-stage model) pooled VE as 100*(1-odds ratio of vaccination) adjusted for country, onset date (in 3-month categories) and age-group (when sample allowed it).

RESULTS

Of 1,393 infants eligible for vaccination, we included 259 cases and 746 controls. Median age was 16 weeks for cases and 19 weeks for controls (p < 0.001). Median birth weight and gestational age were 3,235 g and week 39 for cases, 3,113 g and week 39 for controls. Among cases, 119 (46 %) were vaccinated: 74 with one dose, 37 two doses, 8 three doses. Among controls, 469 (63 %) were vaccinated: 233 with one dose, 206 two doses, 30 three doses. Adjusted VE after at least one dose was 59 % (95 %CI: 36-73). Adjusted VE was 48 % (95 %CI: 5-71) for dose one (416 eligible infants) and 76 % (95 %CI: 43-90) for dose two (258 eligible infants). Only 42 infants were eligible for the third dose.

CONCLUSIONS

Our results suggest moderate one-dose and two-dose VE in infants. Larger sample size would allow more precise estimates for dose one, two and three.

Maternal vaccination provision in NHS maternity trusts across England

BACKGROUND

Vaccinations for seasonal influenza and pertussis have been recommended for pregnant women in England since 2010 and 2012, respectively. Uptake rates are suboptimal with large regional variations. To improve uptake, from 2016 onwards maternity trusts were commissioned to offer pertussis (and other) vaccinations in addition to these being available in primary care. Since 2021, Covid-19 vaccination has also been recommended for pregnant women. Overall maternal vaccination rates are routinely available, but not the relative provision by maternity trusts. We aimed to describe the national picture of maternity trust provision of maternal vaccinations, including how the maternity trust vaccination programme has progressed.

METHODS

Cross-sectional survey plus comparisons with 2017-18 figures for maternity trust provision of pertussis vaccination, and with UKHSA data for total pertussis vaccination.

RESULTS

Twelve NHS commissioners participated (from 13/06/22 to 31/03/23) providing data for 120 (of a total 124) maternity trusts across England. All 120 (100%) trusts were commissioned to deliver influenza, and 107 (89%) to deliver pertussis vaccinations, though not all actually administered the vaccines; 29% offered Covid-19 vaccinations. For 2021-22 we found a mean of 25% (range 0-81.3%) women were vaccinated for pertussis (a large increase compared with previous estimates for 2017-18); and 11% (range 0-74.2%) for influenza, via their maternity trust. Commissioners reported a negative impact of the pandemic on routine vaccination provision. There was indication of efficiency by vaccinating women attending for other appointments. There are diverse mechanisms for reporting pertussis and influenza vaccinations administered at maternity trusts back to primary care, which may be inefficient for maternity staff workload and accuracy of data transfer (especially for pertussis).

CONCLUSION

A high proportion of maternity trusts provide both pertussis and influenza vaccinations, despite a negative impact of the pandemic. Reasons for large between-trust variation in vaccination rates should be explored to improve uptake and equity.

Tdap vaccine in pregnancy and immunogenicity of pertussis and pneumococcal vaccines in children: What is the impact of different immunization schedules?

BACKGROUND

In 2019, the 3 + 1 schedule for children's vaccination (2-4-6-18 months old) was changed for a reduced 2 + 1 schedule (2-4-12 months old) in Quebec, Canada. We compared the post-booster anti-pertussis and anti-pneumococcus IgG antibody concentrations among children of Tdap-vaccinated and unvaccinated mothers for different vaccine schedules and vaccine formulations.

METHODS

We conducted an observational cohort study. An invitation letter to potential participants was provided during a routine vaccination visit. Children's blood samples were analyzed post-booster at 13 (2 + 1 schedule) or 19 (3 + 1 schedule) months of age for antibodies against pertussis antigens (pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (PRN)) and pneumococcal antigens (serotypes 4, 18C, 19A, and 19F). IgG concentrations among children of Tdap-vaccinated and unvaccinated mothers for each vaccination schedule were compared using geometric mean concentrations (GMCs) and GMC ratios (GMRs), adjusting for potentially immune-response-influencing factors (aGMR). Serotype-specific pneumococcal seroprotection rates were also compared.

RESULTS

A total of 360 children were included for pertussis analysis and 248 for pneumococcal analysis. For the 2 + 1 schedule, 13-month-old children of Tdap-vaccinated mothers had lower GMCs against PT, FHA, and PRN, with aGMR (95 %CI) of 0.77 (0.65-0.90), 0.66 (0.55-0.79), 0.72 (0.52-0.99), respectively. For the 3 + 1 schedule, at 19 months old, the interference appeared to be attenuated (higher aGMR values). GMCs against PT were slightly higher in the 3 + 1 than the 2 + 1 schedule: 126.5 IU/ml vs 91.6 IU/ml; aGMR = 1.27. GMCs against PT, FHA and PRN were slightly higher among children who received Infanrix hexa® compared to those who received Pediacel® at 12 months old. For pneumococcal antibodies, at 13 months old, there was no strong evidence of immune interference in children of Tdap-vaccinated mothers.

CONCLUSION

Infant vaccination schedule may influence immune interference associated with maternal Tdap vaccination. More studies are needed to assess the clinical impact of this interference on children's protection.

Impact of vaccinating pregnant women against pertussis on hospitalizations of children under one year of age in a tertiary hospital in Catalonia

INTRODUCTION

The recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalisation rate for pertussis in children under one year of age before and after the implementation of the vaccination programme.

METHODS

Observational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalisation rate of patients under one year of age of the period prior to the vaccination programme (2008-2013) was compared with the period with vaccination programme (2014-2019) in the total of children under one year of age and in 2 subgroups: children under 3 months and between 3-11 months.

RESULTS

Hospitalization rate was significantly lower in the period with vaccination programme in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1000 person-years and 6.47 vs. 13.11 per 1000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36-0.73) for children under one year of age; 0.49 (95% CI 0.32-0.75) for those younger than 3 months and 0.56 (95% CI 0.30-1.03) for those with 3-11 months. No statistically significant differences were observed in the clinical severity between both periods.

CONCLUSION

The introduction of the pertussis vaccination programme in pregnancy was associated with a global lower hospitalisation rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Statistical analysis plan for the OPTIMUM study: optimising immunisation using mixed schedules, an adaptive randomised controlled trial of a mixed whole-cell/acellular pertussis vaccine schedule

Objective

The purpose of this double-blind, randomised, controlled trial is to compare allergic outcomes in children following vaccination with acellular pertussis (aP) antigen (standard of care in Australia) given at 2 months of age versus whole cell pertussis (wP) in the infant vaccine schedule.

Participants

Up to 3000 Australian infants 6 to <12 weeks of age born ≥32 weeks gestation.

Interventions

The intervention is a wP containing vaccine as the first scheduled pertussis vaccine dose instead of an aP containing vaccine.

Outcomes

The primary outcome is a binary indicator of history of IgE-mediated food allergy at the age of 12 months confirmed, where necessary, with an oral food challenge before 18 months of age. Secondary outcomes include (1) history of parent-reported clinician-diagnosed new onset of atopic dermatitis by 6 or 12 months of age with a positive skin prick test to any allergen before 12 months of age, (2) geometric mean concentration in pertussis toxin-specific IgG before and 21 to 35 days after a booster dose of aP at 18 months of age, and (3) sensitisation to at least one allergen by 12 months of age.

Results

Operating characteristics of trial decision rules were evaluated by trial simulation. The selected rules for success and futility approximately maintain type I error of 0.05 and achieved power 0.85 for a reduction in the primary outcome from 10% in the control group to 7% in the intervention group.

Discussion

A detailed, prospective statistical analysis plan (SAP) is presented for this Bayesian adaptive design. The plan was written by the trial statistician and details the study design, pre-specified adaptive elements, decision thresholds, statistical methods, and the simulations used to evaluate the operating characteristics of the trial. Application of this SAP will minimise bias and supports transparent and reproducible research.

Trial registration

Australia & New Zealand Clinical Trials Registry, ACTRN12617000065392. Registered on 12 January 2017

Study protocol

10.1136/bmjopen-2020-042838

Supplementary Information

The online version contains supplementary material available at (10.1186/s13063-021-05874-6).

Molecular epidemiology of Bordetella pertussis and analysis of vaccine antigen genes from clinical isolates from Shenzhen, China

Background

Although pertussis cases globally have been controlled through the Expanded Programme on Immunization (EPI), the incidence of pertussis has increased significantly in recent years, with a “resurgence” of pertussis occurring in developed countries with high immunization coverage. Attracted by its fast-developing economy, the population of Shenzhen has reached 14 million and has become one of the top five largest cities by population size in China. The incidence of pertussis here was about 2.02/100,000, far exceeding that of the whole province and the whole country (both < 1/100,000). There are increasing numbers of reports demonstrating variation in Bordetella pertussis antigens and genes, which may be associated with the increased incidence. Fifty strains of Bordetella pertussis isolated from 387 suspected cases were collected in Shenzhen in 2018 for genotypic and molecular epidemiological analysis.

Methods

There were 387 suspected cases of pertussis enrolled at surveillance sites in Shenzhen from June to August 2018. Nasopharyngeal swabs from suspected pertussis cases were collected for bacterial culture and the identity of putative Bordetella pertussis isolates was confirmed by real-time PCR. The immunization history of each patient was taken. The acellular pertussis vaccine (APV) antigen genes for pertussis toxin (ptxA, ptxC), pertactin (prn) and fimbriae (fim2 and fim3) together with the pertussis toxin promoter region (ptxP) were analyzed by second-generation sequencing. Genetic and phylogenetic analysis was performed using sequences publicly available from GenBank, National Institutes of Health, Bethesda, MD, USA (https://www.ncbi.nlm.nih.gov/genbank/). The antimicrobial susceptibility was test by Kirby-Bauer disk diffusion.

Results

Fifty strains of Bordetella pertussis were successfully isolated from nasopharyngeal swabs of 387 suspected cases, with a positivity rate of 16.79%, including 28 males and 22 females, accounting for 56.0% and 44.0% respectively. Thirty-eight of the 50 (76%) patients were found to be positive for B. pertussis by culture. Among the positive cases with a history of vaccination, 30 of 42 (71.4%) cases had an incomplete pertussis vaccination history according to the national recommendation. Three phylogenetic groups (PG1-PG3) were identified each containing a predominant genotype. The two vaccines strains, CS and Tohama I, were distantly related to these three groups. Thirty-one out of fifty (62%) isolates belonged to genotype PG1, with the allelic profile prn2/ptxC2/ptxP3/ptxA1/fim3-1/fim2-1. Eighteen out of fifty (36%) isolates contained the A2047G mutation and were highly resistant to erythromycin, and all belonged to genotype PG3 (prn1/ptxA1/ptxP1/ptxC1/fim3-1/fim2-1), which is closely related to the recent epidemic strains found in northern China.

Conclusions

The positive rate of cases under one-year-old was significantly higher than that of other age groups and should be monitored. The dominant antigen genotypes of 50 Shenzhen isolates are closely related to the epidemic strains in the United States, Australia and many countries in Europe. Despite high rates of immunization with APV, epidemics of pertussis have recently occurred in these countries. Therefore, genomic analysis of circulating isolates of B. pertussis should be continued, for it will benefit the control of whooping cough and development of improved vaccines and therapeutic strategies.

Impact of vaccinating pregnant women against pertussis on hospitalizations of children under one year of age in a tertiary hospital in Catalonia

INTRODUCTION

The recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalization rate for pertussis in children under one year of age before and after the implementation of the vaccination program.

METHODS

Observational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalization rate of patients under one year of age of the period prior to the vaccination program (2008-2013) was compared with the period with vaccination program (2014-2019) in the total of children under one year of age and in 2subgroups: children under 3 months and between 3-11 months.

RESULTS

Hospitalization rate was significantly lower in the period with vaccination program in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1,000 person-years and 6.47 vs. 13.11 per 1,000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36-0.73) for children under one year of age; 0.49 (95% CI 0.32-0.75) for those younger than 3 months and 0.56 (95% CI 0.30-1.03) for those with 3-11 months. No statistically significant differences were observed in the clinical severity between both periods.

CONCLUSION

The introduction of the pertussis vaccination program in pregnancy was associated with a global lower hospitalization rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Pertussis vaccine effectiveness and duration of protection - A systematic review and meta-analysis

A comprehensive review of observational pertussis vaccine effectiveness (VE) studies is needed to update gaps from previous reviews. We conducted a systematic review of VE and duration of protection studies for the whole-cell (wP) and acellular (aP) pertussis vaccines and conducted a formal meta-analysis using random effects models. Evidence continues to suggest that receipt of any pertussis vaccine confers protection in the short-term against disease although this protection wanes rapidly for aP vaccine. We detected significant heterogeneity in pooled estimates due, in part, to factors such as bias and confounding which may be mitigated by study design. Our review of possible sources of heterogeneity may help interpretation of other VE studies and aid design decisions in future pertussis VE research.

COVID-19 in children: Could pertussis vaccine play the protective role?

While COVID-19 continues to spread across the globe, diligent efforts are made to understand its attributes and dynamics to help develop treatment and prevention measures. The paradox pertaining to children being the least affected by severe illness poses exciting opportunities to investigate potential protective factors. In this paper, we propose that childhood vaccination against pertussis (whooping cough) might play a non-specific protective role against COVID-19 through heterologous adaptive responses in this young population. Pertussis is a vaccine-preventable infectious disease of the respiratory tract and it shares many similarities with COVID-19 including transmission and clinical features. Although pertussis is caused by a bacterium (Bordetella pertussis) while COVID-19 is a viral infection (SARS-CoV-2), previous data showed that cross-reactivity and heterologous adaptive responses can be seen with unrelated agents of highly divergent groups, such as between bacteria and viruses. While we build the arguments of this hypothesis on theoretical and previous empirical evidence, we also outline suggested lines of research from different fields to test its credibility. Besides, we highlight some concerns that may arise when attempting to consider such an approach as a potential public health preventive intervention against COVID-19.

Effectiveness of four doses of pertussis vaccine during infancy diminished in elementary school age: A test-negative case-control study in Japan

OBJECTIVE

The Japanese national immunization program recommends that children receive 4 doses of acellular pertussis vaccine between 3 months and 2 years of age. Nevertheless, the number of pertussis cases is increasing in elementary school children aged 6-12 years. Therefore, a test-negative case-control study was conducted to assess the effectiveness of the pertussis vaccine program.

METHODS

Subjects included children aged ≥3 months who visited a collaborating hospital due to pertussis-specific cough between October 2017 and November 2019. All subjects underwent diagnostic tests for pertussis, and those diagnosed as positive were regarded as cases. Subjects diagnosed as pertussis-negative were classified as controls. Vaccination history was collected using a questionnaire administered to parents with reference to immunization records. Logistic regression models were employed to calculate the odds ratio (OR) and 95% confidence interval for laboratory-confirmed pertussis.

RESULTS

Of 187 recruited subjects (120 cases and 67 controls), questionnaire responses were obtained for 145 subjects (95 cases and 50 controls). Compared with unvaccinated subjects, the vaccine effectiveness (VE) of 4 doses was 70% among all subjects and reached to 90% with marginal significance among subjects under 6 years of age. However, among school-aged subjects, the VE was not suggestive of protection against pertussis (VE: 8%). For vaccinees given 4 doses, the OR for developing pertussis increased significantly with longer duration since the fourth dose (compared with <4.5 years, OR of 6.0-8.2 years = 5.74; OR of ≥8.3 years = 3.88; P for trend by duration < 0.01).

CONCLUSION

Effectiveness of administering 4 doses of pertussis vaccine during infancy decreases with time passed since the fourth dose. This regimen does not protect school-aged children against pertussis.

The effects of manufacture processes on post-translational modifications of bioactive proteins in pertussis vaccine

Because the increasing morbidity of pertussis in all age groups worldwide, the quality of pertussis vaccines has aroused a common concern. To improve the quality of pertussis vaccine in research and production, the effects of manufacture processes on post-translational modifications (PTMs) of bioactive proteins in pertussis vaccine were investigated by a liquid chromatography quadruple - time of flight mass spectrometer (LC-Q-TOF) method in this study. The main bioactive proteins in pertussis vaccine studied include pertussis toxin (PT), pertactin (PRN) and filamentous hemagglutinin (FHA). The main manufacture processes focused are fermentation techniques, purification techniques and storage conditions. The results show that FHA and PRN are rather stable against PTM as only deamidation (Asn) was detected, which is believed to be due to their larger sizes of the bioactive proteins. For PT, however, all the manufacture processes studied have shown significant effects on types and sites of PTMs. Modifications of oxidation and demethylation (Met) occurred in the PT proteins produced by B. pertussis strain Tohama and stored in suspension in saline solution. However, they were not observed in the PT samples produced from stain CS and stored in powders. Carbamylation (Arg) on multiple sites (in S3, S4 and S5) was observed in the PT produced from 5th generation strain CS of B. pertussis. The high abundance ratio of carbamylation modification was potentially a negative effect on the detoxification of PT, since unmodified Lys was the active site for detoxification. The results obtained in this study provide information for making protection strategies against PTMs in pertussis vaccine in manufacture and storage.

Brand-specific rates of pertussis disease among Wisconsin children given 1-4 doses of pertussis Vaccine, 2010-2014

BACKGROUND

Acellular pertussis vaccines were initially licensed based on placebo-controlled efficacy trials, but such trials are no longer ethical. The effectiveness of current pertussis vaccines among properly vaccinated children <5 years is so high that a randomized trial is infeasible. Fluctuations in pertussis incidence and characteristics of the US vaccine marketplace make selection of suitable controls for a case-control study problematic. To satisfy an FDA requirement to evaluate rates of pertussis following licensure of Pentacel® vaccine, we used a case-cohort study design with a novel method for characterizing the cohort population.

METHODS

This prospective, observational study was conducted in Wisconsin from 2010 to 2014 among Wisconsin residents <60 months of age who received ≤four doses of pertussis vaccine (surveillance population). Cases were identified by the Wisconsin Division of Public Health. Characteristics and pertussis vaccinations of the surveillance population were estimated by ongoing random telephonic survey. The primary objective was to determine rates of pertussis disease among those who received only Pentacel vaccine (Group 1) vs those who received a single brand of vaccine other than Pentacel vaccine (Group 2).

RESULTS

1195 pertussis cases were identified. It was estimated that the surveillance population accrued a total of 1,133,403 person-years (Group 1, 39%; Group 2, 41%; Group 3 [those not in Group 1 or Group 2], 20%). Pertussis rates were similar in Group 1 (98.9/100,000) and Group 2 (96.2/100,000); rate ratios were 1.03 (unadjusted; 90% CI, 0.92-1.15) and 0.99 (adjusted; 90% CI, 0.89-1.12). Persons with one or more delayed vaccinations had a 66% higher risk of pertussis (90% CI, 39-96%).

DISCUSSION

Pertussis protection was not found to differ for recipients of the newly licensed vs other available pertussis vaccines. Delayed vaccination substantially increased risk of pertussis. Sample survey methodology was able to characterize the study cohort and enable an otherwise-infeasible study. Clinical Trial Registry number: ClinicalTrials.gov, NCT01129362.

Safety and immunogenicity of the epicutaneous reactivation of pertussis toxin immunity in healthy adults: a phase I, randomized, double-blind, placebo-controlled trial

OBJECTIVES

Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults.

METHODS

This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70.

RESULTS

Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 μg (n = 25), Viaskin-PT 50 μg (n = 25), laser + Viaskin-PT 25 μg (n = 5), laser + Viaskin-PT 50 μg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 μg and 50 μg (139.87 (95% CI 87.30-224.10) and 121.76 (95% CI 95.04-156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37-89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 μg (4/5 (80.0%), 95% CI 28.4-99.5) and 50 μg (22/25 (88.0%), 95% CI 68.8-97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0-26.5).

CONCLUSIONS

Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT03035370) and was funded by DBV Technologies.

Pertussis and influenza immunisation coverage of pregnant women in New Zealand

BACKGROUND

Immunisation is an important public health policy and measuring coverage is imperative to identify gaps and monitor trends. New Zealand (NZ), like many countries, does not routinely publish coverage of immunisations given during pregnancy. Therefore, this study examined pregnancy immunisation coverage of all pregnant NZ women between 2013 and 2018, and what factors affected uptake.

METHODS

A retrospective cohort study of pregnant women who delivered between 2013 and 2018 was undertaken using administrative datasets. Maternity and immunisation data were linked to determine coverage of pertussis and influenza vaccinations in pregnancy. Generalised estimating equations were used to estimate the odds of receiving a vaccination during pregnancy.

RESULTS

From 2013 to 2018 data were available for 323,622 pregnant women, of whom 21.7% received maternal influenza immunisations and 25.7% maternal pertussis immunisations. Coverage for both vaccines increased over time, pertussis increased from 10.2% to 43.6% and influenza from 11.2% to 30.8%. The odds of being vaccinated, with either vaccine, during pregnancy increased with increasing age and decreasing deprivation. Compared to NZ European or Other women, Māori and Pacific women had lower odds of receiving a maternal pertussis (OR:0.55, 95% CI: 0.54, 0.57; OR:0.60, 95% CI: 0.58, 0.62, respectively) and influenza (OR: 0.69, 95% CI: 0.67, 0.71; OR:0.90, 95% CI: 0.87, 0.94, respectively) immunisations during pregnancy. Women were also more likely to be vaccinated against pertussis if they received antenatal care from a General Practitioner or Obstetrician compared to a Midwife. A similar pattern was seen for influenza vaccination.

CONCLUSION

Gaps in maternal coverage for pertussis and influenza exist and work is needed to reduce immunisation inequities.

Increasing adult vaccinations at a regional supermarket chain pharmacy: A multi-site demonstration project

BACKGROUND

Millions of American adults do not receive the recommended vaccinations each year. Community pharmacies are well positioned to help fill this gap through easy access and innovative patient-centered interventions. The primary goal of this demonstration project was to implement new notification and motivational interviewing processes at a regional supermarket chain pharmacy to increase the number of influenza, pertussis, pneumococcal, and herpes zoster vaccines provided to adults.

METHODS

This prospective, observational project utilized a pre-post design. Algorithms were developed with pharmacy dispensing data to identify vaccine-eligible patients. Pharmacy staff then received automated notifications through one of the following: (1) a vaccine message printed on the prescription receipt or on paper attached to the prescription bag when patients came to the pharmacy; or (2) a patient list generated through commercially-available software listing patient contact information and which vaccine they were eligible to receive. Irrespective of the notification process, pharmacy staff employed motivational interviewing techniques either face-to-face or telephonic to engage patients in conversation about getting vaccinated. Finally, an interface to the statewide vaccination registry was developed and tested to transmit vaccination information from all pharmacy locations.

RESULTS

Ninety-nine pharmacies participated in the demonstration project across western Pennsylvania. A 33% increase in vaccinations was recorded over the prior year. Increases in vaccines were demonstrated in three of the four vaccine types: 45% for influenza, 31% for pertussis, and 7% for pneumococcal vaccinations. A decrease of 5% was observed for herpes zoster vaccinations. A successful connection to the statewide vaccine registry was established and 100% of all vaccines administered were transmitted to the registry.

CONCLUSION

A combination of face-to-face and telephonic interventions with motivational interviewing were successful at increasing adult vaccinations in a regional supermarket chain pharmacy. Equal and sustained prioritization for all vaccines is necessary to achieve increases across all vaccine types.

Pertussis immunization in healthcare workers working in pediatric settings: Knowledge, Attitudes and Practices (KAP) of Occupational Physicians. Preliminary results from a web-based survey (2017)

Introduction

The present study aims to characterize knowledge, attitudes and practices in a sample of occupational physicians (OPh) towards pertussis immunization in healthcare workers (HCWs) from pediatric settings.

Material and methods

A total of 148 OPh (45.9% males, mean age of 40.3 ± 13.2 years) compiled a web questionnaire including a knowledge test on Italian recommendations for HCWs, epidemiology and pathology of pertussis infection, being then investigated about risk perceptions and vaccination practices. A General Knowledge Score (GKS) and a Risk Perception Score (RPS) were calculated. Multivariate odds ratios (OR) for predictors of vaccine propensity were calculated through regression analysis.

Results

78 participants regularly recalled pertussis vaccination status and/or performed pertussis vaccination in HCWs (52.7%). Proactive status was correlated with the aim to avoid pertussis infection in HCWs and its diffusion to other adults (p < 0.001, both statements). GKS was satisfying (72.4% ± 14.9), but participants underestimated the clinical issues of pertussis infection (RPS 60.8% ± 9.5) when confronted with influenza (73.9% ± 10.9) and HBV infection (68.1% ± 10.1). GKS and RPS were well correlated (r = 0.244, p = 0.003). Eventually, a better GKS and the aim to avoid pertussis infection in HCWs were predictive of a proactive status for pertussis vaccination (OR 4.186 95%CI 1.809-9.685 and OR 11.459, 95%CI 3.312-39.651, respectively).

Conclusions

Adherence of OPh to HCWs pertussis vaccination was unsatisfying. As knowledge status was predictive for vaccine propensity, information programs for OPh should be more appropriately designed, stressing that HCWs may represent a significant reservoir for pertussis infection in high risk groups (e.g. children/newborns, frail elderly).

Timeliness and equity of infant pertussis vaccination in wales: Analysis of the three dose primary course

Infants aged under one year are at the highest risk of severe complications or death from pertussis infection. Prompt vaccination with a three dose course at two, three and four months of age decreases the amount of time they are vulnerable following waning of maternal antibodies. In Wales, uptake of all three doses of the primary course of pertussis containing vaccine is high. However, timeliness and equity at a population level have not been previously reported. This analysis included 163,733 children born from 1st January 2013 to 31st December 2017. In this cohort 87.9% received the first dose of a pertussis containing vaccine by 12 weeks of age, 87.1% had received all three doses by 24 weeks of age, and 96.3% received three doses by 52 weeks of age. Differences in uptake between those living in the most deprived and least deprived quintiles of Lower Super Output Area (LSOA) were smaller than differences in timeliness, but statistically significant. In 2017 the difference in timely uptake between those living in the most and least deprived quintiles was 4%, 5% and 7% for doses one, two and three respectively. There was a difference of 10% in the proportion of infants receiving all three primary vaccinations on time between the most and least deprived quintile of LSOAs. Consideration is needed on interventions that will help improve timeliness such as enhanced follow up of defaulters, electronic communication between primary care data systems, enhanced health visitor intervention and opportunistic vaccination in those who fail to attend scheduled vaccination appointments. There is also the need for routine monitoring of timeliness and further research into what influences delayed vaccination.

Cost-effectiveness analysis of universal adult immunization with tetanus-diphtheria-acellular pertussis vaccine (Tdap) versus current practice in Brazil

BACKGROUND

A pertussis outbreak occurred in Brazil from 2011 to 2014, despite high coverage of whole-cell pertussis containing vaccines in early childhood. Infants were the most affected. This study aimed to evaluate the cost-effectiveness of introducing universal adult vaccination with Tdap into the National Immunization Program in Brazil.

METHODS

Economic evaluation using a dynamic model to compare two strategies: (1) universal vaccination with single dose of Tdap at 20 years of age and (2) current practice (only pregnant women pertussis vaccination). The health system perspective was adopted. Temporal horizon was 10 years. Discount rate of 5% was applied to costs and benefits. Vaccine effectiveness (VE) was obtained from a population-based observational study. Epidemiological, resource utilization and cost estimates were obtained from the Brazilian Health Information Systems. The primary outcome was cost per life year saved (LYS), based on life expectancy at birth in Brazil in 2015. Univariate and multivariate sensitivity analysis were performed.

RESULTS

Adult vaccination with VE of 82.6% and coverage of 40%, at price of US$7.01 per dose, and assuming herd protection would avoid 167 infant deaths by pertussis, saving 12,325 years of life and costing a total of US$105495891.61, from the health system perspective. The universal immunization would result in ICER of US$8459.13. The results were highly sensitive to disease incidence.

CONCLUSIONS

The results suggest that universal adult vaccination with Tdap would not be a cost-effective intervention for preventing pertussis cases and deaths in infants in Brazil.

Bacille Calmette-Guérin Vaccine Strain Modulates the Ontogeny of Both Mycobacterial-Specific and Heterologous T Cell Immunity to Vaccination in Infants

Differences in Bacille Calmette-Guérin (BCG) immunogenicity and efficacy have been reported, but various strains of BCG are administered worldwide. Since BCG immunization may also provide protection against off-target antigens, we sought to identify the impact of different BCG strains on the ontogeny of vaccine-specific and heterologous vaccine immunogenicity in the first 9 months of life, utilizing two African birth cohorts. A total of 270 infants were studied: 84 from Jos, Nigeria (vaccinated with BCG-Bulgaria) and 187 from Cape Town, South Africa (154 vaccinated with BCG-Denmark and 33 with BCG-Russia). Infant whole blood was taken at birth, 7, 15, and 36 weeks and short-term stimulated (12 h) in vitro with BCG, Tetanus and Pertussis antigens. Using multiparameter flow cytometry, CD4+ T cell memory subset polyfunctionality was measured by analyzing permutations of TNF-α, IL-2, and IFN-γ expression at each time point. Data was analyzed using FlowJo, SPICE, R, and COMPASS. We found that infants vaccinated with BCG-Denmark mounted significantly higher frequencies of BCG-stimulated CD4+ T cell responses, peaking at week 7 after immunization, and possessed durable polyfunctional CD4+ T cells that were in a more early differentiated memory stage when compared with either BCG-Bulgaria and BCG-Russia strains. The latter responses had lower polyfunctional scores and tended to accumulate in a CD4+ T cell naïve-like state (CD45RA+CD27+). Notably, BCG-Denmark immunization resulted in higher magnitudes and polyfunctional cytokine responses to heterologous vaccine antigens (Tetanus and Pertussis). Collectively, our data show that BCG strain was the strongest determinant of both BCG-stimulated and heterologous vaccine stimulated T cell magnitude and polyfunctionality. These findings have implications for vaccine policy makers, manufacturers and programs worldwide and also suggest that BCG-Denmark, the first vaccine received in many African infants, has both specific and off-target effects in the first few months of life, which may provide an immune priming benefit to other EPI vaccines.

Maternity staff immunization coverage against pertussis and maternal vaccination practices: Results of a 2017 cross-sectional survey in five public maternity hospitals

OBJECTIVES

To conduct an audit of vaccination practices against pertussis in maternity wards to assess immunization practices targeting women, knowledge and awareness among health professionals and their involvement in the vaccination process, and to estimate their vaccine coverage.

MATERIALS AND METHODS

2017 cross-sectional descriptive survey using a data collection sheet of immunization practices targeting women and an anonymous questionnaire for health professionals whose vaccine coverage had been documented by the occupational health service.

RESULTS

Five public maternity wards participated: one had a vaccination policy for women; 426 of 822 health professionals completed the questionnaire, 76% (from 50% of all residents to 83% of nurses) declared their vaccination status as up to date. Staff files in occupational health services showed that 69% of 822 health professionals received at least one vaccine booster during adulthood (57% less than 10 years before the survey); documented vaccination coverage rates ranged from 75% for residents to 91% for senior physicians. Occupational physicians and family physicians respectively performed 41% and 34% of vaccinations. While knowledge regarding vaccines was good, only 47% of health professionals declared prescribing them and 18% declared administering the anti-pertussis vaccine "often" or "very often".

CONCLUSIONS

Updated data is needed to confirm the reported increase as participating centers are not representative of all birth centers. The active role of health professionals in vaccination-based pertussis prevention needs to be reinforced.

Randomized study of immune responses to two Tdap vaccines among adolescents primed with DTaP and comparison with results among adolescents primed with DTwP

BACKGROUND

It has been reported that persons primed with acellular (DTaP) pertussis vaccines have reduced duration of pertussis protection compared with those primed with whole-cell (DTwP) vaccines. However, due to the rapid transition to acellular vaccines, studies attempting directly to compare protection among DTaP-primed vs DTwP-primed individuals are subject to confounding by age and other limitations of ecological studies. Using validated assay results and stored sera from multiple Tdap studies, we evaluated two licensed Tdap vaccines among DTaP-primed adolescents to allow comparison with results obtained in the same laboratory from earlier studies involving DTwP-primed adolescents.

METHODS

Participants 11-12 years of age who had received exactly 5 doses of DTaP vaccine prior to 7 years of age were randomly assigned in 2012 to receive one of two licensed Tdap vaccines. Serum specimens obtained pre- and post-vaccination were assayed for responses to the vaccines. Current results were then compared to results obtained in the same laboratory from prior randomized Tdap studies conducted among adolescents primed with DTwP or DTaP.

RESULTS

Both Tdap vaccines produced strong antibody responses to diphtheria and tetanus; responses to contained pertussis antigens were consistent with the differing levels of those antigens in each Tdap vaccine. However, postvaccination pertussis antibody responses were as much as 71% lower in these DTaP-primed adolescents compared with responses among DTwP-primed adolescents in a prior study of the same two Tdap vaccines. In contrast, results from the present study were similar to those seen in another study of Tdap among DTaP-primed adolescents.

DISCUSSION

Taken together, these results from randomized clinical trials provide direct evidence of reduced antibody responses to both licensed Tdap vaccines among adolescents primed with DTaP vaccine, compared with adolescents primed with DTwP vaccine. Clinical trial registry number: ClinicalTrials.gov, NCT01629589.

Low tetanus-diphtheria-acellular pertussis (Tdap) vaccine coverage among healthcare workers in a quaternary university hospital in São Paulo, Brazil: need for continuous surveillance and implementation of active strategies

Introduction

Vaccination with tetanus-diphtheria-acellular pertussis (Tdap) has been recommended for healthcare workers (HCWs) by Brazilian Ministry of Health since November 2014.

Objective

To describe the strategies implemented to improve Tdap uptake, cumulative vaccine coverage after each intervention, variables associated to Tdap vaccination, and reasons for non-vaccination among HCWs of the main building of a quaternary hospital attached to the Sao Paulo University Medical School.

Methods

A list of HCWs eligible for pertussis vaccination was generated. From April to December 2015, the following interventions were implemented: note on intern journal reminding the importance of pertussis vaccination; email to the head nurses strengthening vaccine recommendations; lectures on pertussis and Tdap for physicians of Obstetrics and Neonatology Clinics; on-site vaccination by mobile teams at the Obstetrics, Neonatology, and Anesthesiology Clinics. Vaccine coverage was accessed at the end of each month. Multivariate Poisson regression model with a robust error variance was used to evaluate variables associated with Tdap vaccination. Reasons for non-vaccination were evaluated from January to May 2017 through phone calls for HCWs who had not received Tdap.

Results

The study included 456 HCWs. After the interventions, Tdap coverage raised from 2.8% to 41.2%. In the multivariate analysis, occupation (physician), working place (obstetrics or anesthesiology) and influenza vaccination in 2015 were independently associated to Tdap vaccination. The main reason for non-vaccination was unawareness of Tdap recommendations.

Conclusions

Tdap uptake among HCWs was low in our hospital. Providing vaccination at convenient places/times for HCW seems to be the most efficient strategy to increase vaccine uptake.

Randomized controlled trial of centralized vaccine reminder/recall to improve adult vaccination rates in an accountable care organization setting

Our objectives were to assess 1) effectiveness of using Colorado's Immunization Information System (CIIS) to send out vaccine reminder/recalls (R/Rs) centrally vs. usual care for adult vaccine delivery within an accountable care organization (ACO) and 2) practice staff's perception of centralized R/R. From 9/2016 to 4/2017, we conducted a randomized controlled trial among adults enrolled in a Medicaid ACO at six healthcare entities. Adults were divided into two strata: 15,153 age 19–64 and 616 age 65+. Adults age 19–64 who needed influenza and/or Tdap vaccine, and adults age 65+ who needed influenza, and/or Tdap, and/or a pneumococcal vaccine were randomized to receive up to 3 R/Rs by autodialed telephone and mail or usual care. Documentation of receipt of any needed vaccines in CIIS within six months was the primary outcome. We assessed intervention effectiveness using mixed effect logistic regression. Thirteen semi-structured exit interviews were conducted with staff from each healthcare entity. The intervention was not associated with the primary outcome for the age 19–64 population [OR 1.06 (95% CI 0.98–1.15)] or age 65+ population [(OR 0.96 (0.69–1.32)]. Practice staff perceived the intervention to be beneficial and not burdensome. Perceived barriers included lack of availability of appointments and adults receiving only influenza vaccine when other vaccines were needed. In conclusion, centralized R/R was not effective at improving adult vaccination rates in a Medicaid ACO. Future studies should consider better harmonizing vaccine centralized R/Rs with vaccine delivery efforts within the practice setting.

Clinical Trials Registration Number: NCT02133391.

Development and implementation of standardized method for detecting immunogenicity of acellular pertussis vaccines in Korea

Purpose

There is no standard method for confirming the immunogenicity of acellular pertussis vaccines. We tried to develop a local standard method for evaluating the immunogenicity of the three-component of acellular pertussis vaccines which was developed by a Korean local company.

Materials and Methods

The developed pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin) were evaluated by in-house enzyme-linked immunosorbent assay (ELISA) using 189 negative sera, 25 positive sera, and 73 paired sera (pre- and post-Tdap [tetanus, diphtheria, and acellular pertussis] vaccinated sera). ELISA units were calculated by the reference line method, compared with World Health Organization reference sera, and the cut-off value was calculated using negative sera.

Results

When compared to National Institute for Biological Standards and Control control antigen (NIBSC) control antigens, the developed pertussis toxin (PT) and filamentous haemagglutinin (FHA) antigens were 203.48 and 61.60 IU/µg, respectively. Each in-house ELISA was established by validating the coefficients of variation % (PT, 11.53%; FHA, 8.60%; pertactin [PRN], 9.86%) obtained from the results of inter- and intra-assay variation. Also, the cut-off values of PT, FHA, and PRN were 11.65, 38.95, and 5.66 EU/mL, respectively. The distributions of antibody levels in paired showed that 93.15% (68/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were higher than a 100% increase after vaccination. Additionally, the values of 89.04% (65/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were below each cut-off point.

Conclusion

We established an in-house ELISA method using self-developed antigens, and these immunoassays have provided a way to standardize measuring the immunogenicity of newly developed vaccines, through single- and dual-serology.

Epidermal micro-perforation potentiates the efficacy of epicutaneous vaccination

The skin is an immune organ comprised of a large network of antigen-presenting cells such as dendritic cells, making it an attractive target for the development of new vaccines and immunotherapies. Recently, we developed a new innovative and non-invasive vaccination method without adjuvant based on epicutaneous vaccine patches on which antigen forms a dry deposit. Here we describe in mice a method for potentiating the efficacy of our epicutaneous vaccination approach using a minimally invasive and epidermis-limited skin preparation based on laser-induced micro-perforation. Our results showed that epidermal micro-perforation increased trans-epidermal water loss, resulting in an enhancement of antigen solubilization from the surface of the patch, and increased the quantity of antigen delivered to the epidermis. Importantly, this was not associated with an increase in systemic passage of the antigen. Skin micro-perforation slightly activated keratinocytes without inducing an excessive level of local inflammation. Moreover, epidermal micro-perforation improved antigen capture by epidermal dendritic cells and specifically increased the level of Langerhans cells activation. Finally, we observed that epidermal micro-perforation significantly increased the level of the specific antibody response induced by our epicutaneous Pertussis vaccine candidate containing non-adsorbed recombinant Pertussis Toxin and reduced the amount of antigen dose required. Overall, these data confirm the benefit of a minimal and controlled epidermal preparation for improving the effectiveness of an epicutaneous patch-based vaccine, without adversely affecting the safety of the method.

Does the economic recession influence the incidence of pertussis in a cosmopolitan European city?

Background

In the last few years, pertussis has re-emerged worldwide. The aim of this article is to study how the incidence of the disease has evolved in Barcelona city over a 16-year period, and determine which factors are associated with the evolution of the disease. We discuss the causes of the observed changes considering different possibilities such as vaccination coverage, vaccine effectiveness, increased surveillance or the effect of the current economic recession.

Methods

We performed a cross-sectional, observational, population-based descriptive study using data for the 2000–2015 period from the notifiable diseases register maintained by Barcelona Public Health Agency. We used Poisson regression to compute adjusted odds ratios (aOR) and their corresponding 95% confidence intervals (CI).

Results

A total of 1791 cases were registered. The incidence of the disease increased throughout the city from 2011 onwards. While children under 1 year of age had the highest-incidence and were the most at risk (aOR = 27.18, CI:23.51–31.44), we found that the age of affected children was higher in the last years. Incidence proportion (PRR) was lower among foreign-born children than native children (PRR = 0.43 CI:0.32–0.58). In the whole-cell vaccine period (2000–2004), the percentage of cases under 1 year of age who received the vaccine was lower than in 2005–2015 when the acellular vaccine was used (p = 0.01), suggesting a lower efficacy of the acellular vaccine. However, vaccination coverage in children under 6 years remained high (~ 90%), and there were no significant year-to-year variations (p = 0.757). Moreover, there did not appear to be any significant restrictions in medical care. According to the index of disposable household income (DHI), pertussis incidence increased from 2011 onwards in all neighbourhoods and remained higher in those with lower DHI.

Conclusions

The noteworthy increase in pertussis incidence does not seem to be due to the economic recession, but to other factors here described.

Impact of implementing a technology platform in community pharmacies to increase adult immunizations rates

Over the course of this project, we utilized pharmacists at 159 community pharmacies in Nebraska and Iowa to administer vaccinations to adults 19 years of age or older with the objective of improving immunization rates in both states. We implemented a pharmacy-based technology platform and partnered with public health via the state immunization registries of both states to ensure that immunizations provided at the pharmacy were transmitted to the statewide registry, for which reporting is currently voluntary for health care providers. After using the technology platform for one year, an increase of immunization rates for influenza, herpes zoster, and pertussis vaccination rates by 37%, 12%, and 74%, respectively, was recorded in comparison to the prior year numbers. However, there was about 16% decrease in vaccination rates for pneumococcal vaccine. For the first time, the project's participating pharmacies in Nebraska reported immunization counts to their state's immunization registries. This project leveraged community pharmacies as healthcare destinations to achieve further gains in increasing immunization rates, improving the health of adults, and creating a community-wide network for prevention.

Antenatal influenza and pertussis vaccination in Western Australia: a cross-sectional survey of vaccine uptake and influencing factors

Background

Influenza and pertussis vaccines have been recommended in Australia for women during each pregnancy since 2010 and 2015, respectively. Estimating vaccination coverage and identifying factors affecting uptake are important for improving antenatal immunisation services.

Methods

A random sample of 800 Western Australian women ≥18 years of age who gave birth between 4th April and 4th October 2015 were selected. Of the 454 (57%) who were contactable by telephone, 424 (93%) completed a survey. Data were weighted by maternal age and area of residence to ensure representativeness. The proportion immunised against influenza and pertussis was the main outcome measure; multivariate logistic regression was used to identify factors significantly associated with antenatal vaccination. Results from the 2015 study were compared to similar surveys conducted in 2012–2014.

Results

In 2015, 71% (95% CI 66–75) of women received pertussis-containing vaccine and 61% (95% CI 56–66) received influenza vaccine during pregnancy; antenatal influenza vaccine coverage was 18% higher than in 2014 (43%; 95% CI: 34–46). Pertussis and influenza vaccine were co-administered for 68% of the women who received both vaccines. The majority of influenza vaccinations in 2015 were administered during the third trimester of pregnancy, instead of the second trimester, as was observed in prior years. Women whose care provider recommended both antenatal vaccinations had significantly higher odds of being vaccinated against both influenza and pertussis (OR 33.3, 95% CI: 15.15–73.38). Of unvaccinated mothers, 53.6% (95% CI: 45.9–61.3) and 78.3% (95% CI: 70.4–85.3) reported that they would have been vaccinated against influenza and pertussis, respectively, if their antenatal care provider had recommended it.

Conclusions

Pertussis vaccination coverage was high in the first year of an antenatal immunisation program in Western Australia. Despite a substantial increase in influenza vaccination uptake between 2014 and 2015, coverage remained below that for pertussis. Our data suggest influenza and pertussis vaccination rates of 83% and 94%, respectively, are achievable if providers were to recommend them to all pregnant women.

Impact of maternally derived pertussis antibody titers on infant whole-cell pertussis vaccine response in a low income setting

BACKGROUND

Maternal vaccines against pertussis are not yet recommended in the developing world. Besides unclear burden estimates, another concern is that transplacental transfer of maternal pertussis antibodies could result in attenuation of the immune response to whole cell pertussis (DTwP) primary vaccination series in infants. This study was taken up to determine whether higher levels of maternal pertussis antibodies attenuate immune response of infants to DTwP vaccination series given at 6-10-14 weeks of age.

METHODOLOGY

A total of 261 pregnant women and their infants from four low-income settlements in Karachi, Pakistan were enrolled in this study. The study endpoints were infant antibody titers for Pertussis toxin (PTx), Filamentous hemagglutinin antigen (FHA), Pertactin (PRN) and Fimbriae type 2/3 (FIM) - from birth through 18 weeks of age. Cord blood or pre-vaccine pertussis antibody titers indicate the concentration of maternal antibodies transferred to infants. Linear regression models were used to determine the association between higher maternal antibody titers and infant immune response to DTwP vaccine. Geometric Mean Ratio (GMR) was calculated as the ratio of infant antibody titers at specified time points against the maternal antibody titers at the time of delivery.

RESULTS

At eighteen weeks of age, the adjusted β regression coefficient for PTx was 0.06 (95% CI: -0.49-0.61), FHA 0.02 (95% CI: -0.26 -0.29), PRN 0.02 (95%CI -0.38- 0.43), and FIM 0.17 (95%CI: -0.21-0.54). Among infants who received at least two doses of DTwP vaccine, higher maternal antibody titers did not have any attenuating effect on infant post-immunization antibody titers against all four pertussis antigens.

CONCLUSION

Maternal pertussis antibodies did not attenuate infant's immune response to pertussis antigens in DTwP primary vaccine given at 6-10-14 weeks of age.

Development of a thermostable spray dried outer membrane vesicle pertussis vaccine for pulmonary immunization

Worldwide resurgence of whooping cough calls for improved, next-generation pertussis vaccines that induce broad and long-lasting immunity. A mucosal pertussis vaccine based on outer membrane vesicles (omvPV) is a promising candidate. Further, a vaccine that is stable outside the cold chain would be of substantial advantage for worldwide distribution and application. A vaccine formulated as a powder could both stabilize the vaccine as well as make it suitable for pulmonary vaccination. To that end, we developed a spray dried omvPV with improved stability compared to the liquid omvPV formulation. Spray drying did not affect the structural integrity of the omvPV. The antigenicity of Vag8, a major antigen in omvPV was diminished slightly and an altered tryptophan fluorescence indicated some changes in protein structure. However, when administered via the pulmonary route in mice after reconstitution, spray dried omvPV showed comparable immune responses and protection against challenge with live B. pertussis as liquid omvPV. Mucosal IgA and Th17 responses were established in addition to broad systemic IgG and Th1/Th17 responses, indicating the induction of an effective immunity profile. Overall, a spray dried omvPV was developed that maintained effective immunogenic properties and has an improved storage stability.

The Prevalence of PCR-Confirmed Pertussis Cases in Palestine From Archived Nasopharyngeal Samples

BACKGROUND

Pertussis caused by Bordetella pertussis is a vaccine-preventable disease causing whooping cough in humans of all ages. This study reports infection rate of pertussis in Palestine between the years 2004-2008 from archived nasopharyngeal samples collected from clinically- suspected cases.

METHODS

A convenience archived DNA samples collected from 267 clinically-suspected pertussis cases were investigated for B. pertussis. Laboratory diagnosis was done by examining all DNA samples using polymerase chain reaction (PCR).

RESULTS

Approximately 49% (130/267) were confirmed by PCR. A pertussis peak was shown to occur in 2008 with 77% (100/130) of PCR-confirmed cases isolated in that year. PCR-confirmed cases existed in all Palestinian districts with highest rate in Ramallah, Bethlehem, Jenin and Al-Khalil. Half of the PCR-confirmed cases (68/130) were less than 2 months old. The positivity rate among who had three doses of vaccine (at 2, 4 and 6 months) was 38%, and became 50% with the fourth dose at 12 months.

CONCLUSION

The prevalence of pertussis was found to be significantly high among infants less than 2 months old. Active pertussis surveillance using rapid PCR assays is essential, as it is helpful in prompt diagnosis and treatment of patients with pertussis.

Novel intranasal pertussis vaccine based on bacterium-like particles as a mucosal adjuvant

Pertussis, or whooping cough, has recently reemerged as a major public health threat despite high levels of vaccination. The development of a novel pertussis vaccine, especially an intranasal (i.n.) vaccine is undoubtedly necessary, and mucosal adjuvants have been explored to enhance the immune response. In the present study, bacterium-like particles (BLPs) were adopted as a mucosal adjuvant for an i.n. pertussis vaccine and evaluated on the ability to induce serum and mucosal antibodies as well as potency against i.n. challenge in mice. Groups with or without aluminum adjuvant were also evaluated through both i.n. and intraperitoneal inoculations. Vaccination with BLPs via the i.n. route led to rapid IgG and IgA production and provided strong protection against inflammation induced by infection. The results support an i.n. pertussis vaccine with BLPs adjuvant as a promising candidate to elicit protective immunity against whooping cough.

Challenges of interpreting epidemiologic surveillance pertussis data with changing diagnostic and immunization practices: the case of the state of São Paulo, Brazil

Background

A significant increase in pertussis incidence occurred in Brazil, from 2011 to 2014, despite high coverage of childhood immunization with whole-cell-pertussis (wP) containing vaccines. This study presents pertussis surveillance data from São Paulo state and discusses the challenges to interpret them considering pertussis cyclic epidemic behavior, the introduction of new diagnostic techniques and new vaccination strategies, and enhanced disease awareness during epidemics.

Methods

Observational study including pertussis cases reported to the Surveillance System in São Paulo state, from January 2001 to December 2015. Pertussis cases data were retrieved from the National Notifiable Diseases Information System (SINAN) website and from São Paulo state Epidemiological Surveillance Center (CVE/SP) database. Vaccination coverage and homogeneity data were collected from the Unified Health System Department of Informatics (DATASUS). We presented cases distribution by year, age group and diagnostic criteria and calculated pertussis incidence rates. The proportions of cases among different age groups were compared using chi-square test for trend.

Results

Infants less than 1 year of age were the most affected during the whole period, but the proportions of cases in this age group had a significant decreasing trend, with significant increase in the proportions of cases reported among older age groups (1–4, 5–10 and ≥20 years). Cases among infants aged less than 6 months represented ≥90% of all cases in children less than 1 year of age in all but 2 years (2012 and 2015). A non-significant decrease in the proportion of cases among infants aged < 2 months was observed in parallel to a significant increase in the proportion of cases in infants aged 6–11 months.

Conclusions

A pertussis outbreak has occurred in a state with universal use of wP vaccine. The disease cyclic behavior has probably had a major role in the increased incidence rates registered in São Paulo state, from 2011 to 2014, as well as in the decreased incidence in 2015. Maternal vaccination cannot explain the drop in the number of cases among all age groups, in 2015, as herd protection is not expected, but may have had an impact on the number of cases in infants aged < 2 months.

Bordetella Pertussis virulence factors in the continuing evolution of whooping cough vaccines for improved performance

Despite high vaccine coverage, whooping cough caused by Bordetella pertussis remains one of the most common vaccine-preventable diseases worldwide. Introduction of whole-cell pertussis (wP) vaccines in the 1940s and acellular pertussis (aP) vaccines in 1990s reduced the mortality due to pertussis. Despite induction of both antibody and cell-mediated immune (CMI) responses by aP and wP vaccines, there has been resurgence of pertussis in many countries in recent years. Possible reasons hypothesised for resurgence have ranged from incompliance with the recommended vaccination programmes with the currently used aP vaccine to infection with a resurged clinical isolates characterised by mutations in the virulence factors, resulting in antigenic divergence with vaccine strain, and increased production of pertussis toxin, resulting in dampening of immune responses. While use of these vaccines provide varying degrees of protection against whooping cough, protection against infection and transmission appears to be less effective, warranting continuation of efforts in the development of an improved pertussis vaccine formulations capable of achieving this objective. Major approaches currently under evaluation for the development of an improved pertussis vaccine include identification of novel biofilm-associated antigens for incorporation in current aP vaccine formulations, development of live attenuated vaccines and discovery of novel non-toxic adjuvants capable of inducing both antibody and CMI. In this review, the potential roles of different accredited virulence factors, including novel biofilm-associated antigens, of B. pertussis in the evolution, formulation and delivery of improved pertussis vaccines, with potential to block the transmission of whooping cough in the community, are discussed.

Pertussis and parapertussis in children and adults with a persistent cough: an observational study

PURPOSE

We aimed to determine the prevalence, symptoms and course of pertussis and parapertussis among patients at any age with a cough of unknown aetiology that had lasted for ≥ 7 days and to assess the diagnostic value of the symptoms included in the World Health Organisations' (WHO) clinical case definition of pertussis.

METHODS

Patients were enrolled between the 23 April 2012 and 31 December 2014 at 25 general practitioner (GP) centres and three paediatric hospitals. Pertussis was confirmed by culture and/or polymerase chain reaction (PCR) and/or quantitative serology. Parapertussis was confirmed by culture and/or PCR.

RESULTS

Altogether, 549 patients were recruited. Of them, 22 (4.0%; 95% CI 2.5-6.0) had pertussis (predominately diagnosed by positive serology 17/22) and 7 (1.3%; 95% CI 0.5-2.6) had parapertussis. Patients with pertussis were more likely to have inspiratory whooping and posttussive emesis than those with a cough of another/unknown aetiology. However, the presence or absence of these two symptoms did not definitively confirm or exclude pertussis. The sensitivity and specificity of the WHO's clinical definition was 0.77 and 0.38, respectively.

CONCLUSIONS

The prevalence of pertussis and parapertussis among patients with a persistent cough of unknown aetiology in Estonia is low. As clinical symptoms alone cannot be used to distinguish pertussis, we recommend that laboratory testing for pertussis is performed in all patients with a persistent cough regardless of age.

Whooping cough surveillance in France in pediatric private practice in 2006-2015

BACKGROUND

Increasing incidence of whooping cough (pertussis) has been reported in many countries, attributed to a switch from whole-cell pertussis-containing vaccine (wPV) to acellular PV (aPV) and circulation of the pertactin non-producing Bordetella pertussis. The present study aimed to estimate the duration of immunity conferred by PVs in children in France with data from an ongoing pediatric ambulatory surveillance of pertussis.

METHODS

A total of 64 pediatricians throughout France enrolled children with suspected pertussis. A standardized data form was used to collect data on age sex, vaccination status, brand of wPV or aPV and source of infection. Confirmed cases were positive on culture and/or real-time Polymerase Chain Reaction (for B.-non-classified or B. pertussis or B. parapertussis) and/or pertussis serology.

RESULTS

Between October 2006 and December 2015, 149 cases of confirmed Bordetella infections were reported, 86 infected with B. pertussis and 55 B. non-classified. Fifteen children (10.1%) were not vaccinated, and 26 (17.4%) were partially vaccinated. The mean age was greater for children who received 4 doses of wPV (11.3±2.2, p<0.001) or a combination of wPV and aPV (10.5±3.3, p<0.001) than only aPV (7.2±2.4years). The mean duration of cough before a visit to a pediatrician was longer for children with wPV or a combination of wPV and aPV than only aPV (23.8±10.1 and 25.0±25.6vs 13.6±10.0days).

CONCLUSION

Despite the use of a more sensitive diagnostic method and emergence of pertactin non producing B. pertussis, in France context, aPV-induced immunity still protects against pertussis; however, the mean duration of immunity is about 6 to 7years, compared to 9years for wPV vaccine, after the primary vaccination and one booster (3+1 doses).

What drives pregnant women's decisions to accept the pertussis vaccine?

The aims of this study were to identify factors associated with pregnant women's intention to receive the pertussis vaccine during pregnancy, using the Health Belief Model; while comparing between pregnant native-born Israeli women and Israeli women born in the former Soviet Union. Convenience and snowball sampling methods were used to recruit 200 pregnant Israeli native-born women and women born in the former Soviet Union. Data were collected using a cross-sectional questionnaire survey. Regression results revealed that susceptibility to pertussis, seriousness of pertussis, perceived benefits of the vaccine, knowledge of risk factors of pertussis, and general health motivation together explained 76% of the variance of women's intention to receive the pertussis vaccine. Perceived benefits of the vaccine was the most significant factor affecting pregnant women's intention to receive the pertussis vaccine during pregnancy (p<0.05). Native-born women had higher intention to be vaccinated and more positive health beliefs (p<0.05).

Vaccinations against respiratory infections in Arabian Gulf countries: Barriers and motivators

AIM

To study the uptake, barriers and motivators of influenza, pneumococcal, meningococcal and pertussis vaccines among members of public in Arabian Gulf countries.

METHODS

A cross-sectional survey among the Gulf Cooperation Council (GCC) countries’ residents. Data collected electronically through a smartphone app. The survey variables aimed to investigate the respondents’ awareness about vaccines against influenza, pneumococcal, meningococcal and pertussis infections. Collected data concerning the respondents’ socio-demographic characteristics, their perception toward vaccine uptake and the factors that motivate or demotivate them from taking influenza vaccine. The data were analysed statistically using the SPSS v.23.0. Differences in the characteristics of users from different countries were quantified through bivariate analysis. Other important variables and controlling factors were studied using logistic regression.

RESULTS

A total of 1812 respondents participated in the study. Their mean age was 27 years, 82% were male and 24% had ≥ 1 chronic diseases. The overall uptake of influenza vaccine was 17% (21% among “at risk” people) and ranged from 15% in Saudi Arabia to 24% in Qatar. Doctor’s advice (23%) and a perception of having low body immunity (21%) were the main cited reasons for being vaccinated, whereas unawareness about the vaccine (43%) was the main barrier. The overall uptake of pneumococcal vaccine in the preceding three years was 22% (25% among “at risk” individuals) and ranged from 0% in Bahrain to 79% in Kuwait. The overall uptake of pertussis vaccine was 16% (31% among “vulnerable” people), and ranged from 7% in Saudi Arabia to 75% in Oman. The overall uptake of meningococcal vaccine was 20% (29% among the “at risk” people) and ranged from 3% in Oman to 50% in Bahrain.

CONCLUSION

The vaccination uptake across GCC countries is suboptimal and varies widely across the countries. Further research is needed to unearth the reasons and formulate action plan.

Epidemiology of pertussis in Alberta, Canada 2004-2015

BACKGROUND

We describe the epidemiology of pertussis in Alberta, Canada by person, place, and time between 2004 and 2015, identify outbreak years, and examine vaccination coverage and vaccination timeliness.

METHODS

We used health data from Alberta's Communicable Disease Registry System for the period of January 1, 2004 through August 31, 2015 to identify unique cases of pertussis. Unique cases were deterministically linked to data in Alberta's immunization repository and health care insurance plan registry. Population estimates and vaccination coverage were extracted from Alberta's online Interactive Health Data Application. We estimated pertussis incidence rates per 100,000 persons by year, age group, gender, and health zone. Outbreak years were identified using a one-sided cumulative sum (CUSUM) analysis by comparing annual incidence rates to baseline rates.

RESULTS

Over the period, 3510 cases of pertussis were confirmed by laboratory testing or epidemiological linkage. Incidence rates per 100,000 persons were highest in 2004 (20.5), 2005 (13.6), and 2015 (10.4) for all age groups. Incidence rates were highest among the youngest age groups and decreased as age groups increased. Based on CUSUM analysis, 2008 and 2012 met the criteria for outbreak years. Vaccination coverage was over 90% among the general population, however only 61% of cases received at least one dose. About 60% of cases were diagnosed 5+ years after receiving the vaccine. Approximately 87-91% of vaccinated cases did not receive the first three vaccine doses in a timely manner.

CONCLUSION

Pertussis incidence rates fluctuated over the period across all age groups. The majority of cases had no record of vaccination or were delayed in receiving vaccines. CUSUM analysis was an effective method for identifying outbreaks.

Transiently increased IgE responses in infants and pre-schoolers receiving only acellular Diphtheria-Pertussis-Tetanus (DTaP) vaccines compared to those initially receiving at least one dose of cellular vaccine (DTwP) - Immunological curiosity or canary in the mine?

BACKGROUND

Several previous studies have highlighted the strong Th2-polarising and IgE-promoting activity of the DTaP vaccine, but there is no evidence that this has pathological consequences and accordingly there is no current interest amongst vaccine developers in reformulating DTaP to attenuate these properties. In light of an apparent resurgence in pertussis in many countries, and emerging evidence from other areas of paediatric immunology of IgE-mediated interference with host defence mechanisms, this issue requires more detailed clarification.

METHODS

We have re-evaluated the impact of DTaP-only versus mixed DTwP/DTaP vaccination on Th2-dependent "bystander" IgE responses in three cohorts of children under different priming conditions, encompassing both vaccine-targeted and unrelated antigens including food allergens.

RESULTS

We confirm the generalised IgE-trophic activity of the DTaP vaccine in pre-schoolers and demonstrate similar (albeit transient) effects in infants. We additionally demonstrate that use of an alternative mixed infant priming schedule encompassing an initial dose of DTwP significantly attenuates this property.

INTERPRETATION

Central to our interpretation of these findings are studies demonstrating: (i) mixed DTwP/DTaP priming improves resistance to pertussis disease and attenuates the IgE-stimulatory component of long term vaccine-specific memory; (ii) IgE-mediated mechanisms can interfere with innate antiviral immunity and accordingly exacerbate airway symptoms in infected children. These observations, taken together with the data presented here, suggest a plausible mechanistic link between baseline pertussis-specific IgE titres in DTaP vaccinees and susceptibility to pertussis disease, which merits testing. Retrospective IgE analyses on sera collected from children at the time of presentation with pertussis could resolve this issue.

A prospective cohort study assessing the reactogenicity of pertussis and influenza vaccines administered during pregnancy

BACKGROUND

Pertussis vaccination during pregnancy can prevent 91% of infant infections. In 2015, antenatal pertussis vaccination programs were introduced across Australia.

METHODS

To monitor the safety of this program, pregnant women who received trivalent influenza vaccine (TIV) and/or diphtheria-tetanus-acellular pertussis vaccine (dTpa) were surveyed by text message seven days post-vaccination about possible adverse events following immunization (AEFI). Univariate logistic regression models were used to calculate the odds of reporting an AEFI following dTpa compared to TIV. Similar analyses were used to compare AEFI reported by women who received a previous dose of dTpa in 2011/2012 as part of a state-wide cocooning program.

RESULTS

Of 5155 women, 4347 (84.3%) replied; 10.8% indicated they experienced an AEFI. There was no difference in the proportion of women who reported any reaction by vaccine; however, women who received dTpa were more likely to report a local reaction than women who received TIV (7.1% and 3.2%, respectively; OR: 2.29; 95% CI: 1.61-3.26). There was evidence suggesting local reactions were more common among women with a previous dose of dTpa (11.4%) compared to women with no previous dose (6.0%; OR: 2.00; 95% CI: 0.95-4.25); 11 (0.3%) women reported attending a hospital emergency department. Subsequent follow-up indicated symptoms resolved and mother and infant were healthy. There was no difference in the proportion of women attending hospital by vaccine (p > 0.05).

DISCUSSION

Data on systemic and local reactions following receipt of TIV and dTpa during pregnancy support the safety of antenatal vaccination.

Pertussis: History of the Disease and Current Prevention Failure

Pertussis or whooping cough has been given many names over the centuries. It was first recognized in the Middle Ages and since then various epidemics have been described. Jules Bordet and Octave Gengou isolated Bordetella pertussis, a causative agent for whooping cough, in Paris more than 100 years ago, which created an excellent opportunity to invent a vaccine. In 1914 the whole-cell pertussis vaccine was invented, then in the 1940s it was combined with tetanus and diphtheria toxoids to become DTP and it became widely available. A successive decrease in the incidence of the disease has since been observed. The vaccine has been about 80 % effective in preventing serious disease and death from pertussis. The disadvantage is that the vaccine offers protection for 5-10 years after the last dose of the full vaccination course. The second issue is the question of how to prevent side effects of the whole-cell vaccine. In the 1990s, the acellular vaccine was introduced in the US and gradually replaced the whole-cell vaccine. About 10 years later, a possible failure with the new vaccine has been observed, that is a lack of long-term protection. Nowadays, both vaccines are used, with the acellular vaccine being vastly predominant in most developed countries. Pertussis incidence has increased since the 1980s, but new prevention strategies include booster doses for specific age groups.

Pertussis vaccines: position paper, August 2015--Recommendations

This article presents the World Health Organization's (WHO) recommendations for the use of vaccines against Bordetella pertussis from the WHO position paper on Pertussis vaccines: WHO position paper--August 2015, recently published in the Weekly Epidemiological Record (Pertussis vaccines: WHO position paper. Wkly Epidemiol Rec 2015;90(August(35)):433-60). This position paper summarizes the most recent developments in the field of pertussis disease and its prevention by vaccination. It includes the WHO position on the choice of Pertussis vaccine as well as on the use of additional strategies, particularly vaccination during pregnancy, for prevention of early infant mortality. This document replaces the first WHO position paper on vaccines against disease caused by Pertussis published in 2010 (Pertussis vaccines: WHO position paper. Wkly Epidemiol Rec 2010;85(October(40)):385-400) and incorporates the revised guidance on the choice of pertussis vaccines published in July 2014 (Pertussis vaccines: WHO position paper. Wkly Epidemiol Rec 2014;89(July(30)):337-44). Footnotes to this paper provide a number of core references. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. This paper reflects the recommendations of WHO's Strategic Advisory Group of Experts (SAGE) on immunization. These recommendations were discussed by SAGE at its April 2014 and April 2015 meetings. The evidence presented at the meetings can be accessed at http://www.who.int/immunization/sage/previous/en/index.html.

Universal tetanus, diphtheria, acellular pertussis (Tdap) vaccination of adults: What the Canadian public knows and wants to know. Vaccine. 2015;33:6840-6848. [PMID: 26392011 DOI: 10.1016/j.vaccine.2015.09.012]

Tetanus, diphtheria, and acellular pertussis vaccine (Tdap) is recommended for all adults in Canada but uptake is low. This study measured the knowledge, attitudes, beliefs, and behaviors of Canadian adults to identify potential barriers and facilitators to Tdap uptake. A survey was undertaken on a geographically representative sample of Canadian adults (n=4023) and 8 focus groups (62 participants) were conducted nationwide. The survey revealed that knowledge about pertussis and Tdap was low (38.3% correct answers). Only 36.0% of respondents reported being aware that all adults were recommended to receive Tdap and only 10.7% reported being immunized; 36.7% did not know whether they had received Tdap. Respondents who were aware of the immunization recommendations were twice as likely to be immunized (16.6% vs. 8.3%; p<0.001). Only 9.3% believed that their health care provider thought that Tdap was important for adults. The focus group data supported the survey results. Participants wanted information about pertussis and Tdap communicated through multiple modalities, but a recommendation by their family physician was most important to their decision to be immunized or not. This study demonstrates that current recommendations for universal adult vaccination with Tdap are not reaching the general public in Canada and an alternative strategy will be required to improve Tdap vaccine uptake.

The impact of parental postpartum pertussis vaccination on infection in infants: A population-based study of cocooning in Western Australia

During a pertussis epidemic in 2011-2012 the Western Australian (WA) Department of Health implemented a 'cocooning' programme, offering free pertussis-containing vaccine (dTpa) to new parents. We assessed the impact of vaccinating parents with dTpa on the incidence of pertussis infection in newborns. Births in WA during 2011-2012 were linked to a register of parental pertussis vaccinations and to notified reports of laboratory-proven pertussis in children <6 months of age. Parents who received dTpa during the four weeks after their child's birth were defined as 'vaccinated postpartum.' Cox proportional-hazards methods were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of pertussis infection among infants born to parents vaccinated postpartum vs. unvaccinated parents, adjusted for maternal age, geographic region, timing of birth, and number of siblings. Of 64,364 live-births, 43,480 (68%) infants had at least one vaccinated parent (60% of mothers and 36% of fathers). After excluding records where parent(s) were either vaccinated prior to the birth, vaccinated >28 days after the birth, the vaccination date was uncertain, or the child died at birth (n=42), the final cohort contained 53,149 children, 118 of whom developed pertussis. There was no difference in the incidence of pertussis among infants whose parents were both vaccinated postpartum compared to those with unvaccinated parents (1.9 vs 2.2 infections per 1000 infants; adjusted HR 0.91; 95%CI 0.55-1.53). Similarly, when assessed independently, maternal postpartum vaccination was not protective (adjusted HR 1.19; 95%CI 0.82-1.72). Supplemental sensitivity analyses which varied the time period for parental vaccination and accounted for under-reporting of vaccination status did not significantly alter these findings. In our setting, vaccinating parents with dTpa during the four weeks following delivery did not reduce pertussis diagnoses in infants. WA now provides dTpa vaccine to pregnant women during the third trimester.

Introduction. Maternal immunization - Promises and concerns

In this issue of Vaccine, the maternal immunization platform as an approach to protect mothers and infants against diverse pathogens is presented. Potential vaccine targets and the safety, science, trial designs, ethical considerations, and international perspectives focusing on low and middle income countries (LMIC) are discussed. This information provides a timely update because maternal immunization is increasingly being considered as an intervention to prevent maternal and/or neonatal disease. Prioritization of vaccine targets for maternal immunization by researchers, public health officials and health care workers needs to begin now.

Strategies for increasing adolescent immunizations in diverse ethnic communities

PURPOSE

We sought to identify attitudes and knowledge of adolescent vaccination recommendations for tetanus, diphtheria, and acellular pertussis (Tdap); quadrivalent meningococcal conjugate (MCV4); and human papillomavirus (HPV) vaccines among Hispanic, Somali, and Ethiopian/Eritrean communities in King County, Washington.

METHODS

In-person surveys of Hispanic, Somali, and Ethiopian/Eritrean adolescents (n = 45) and parents of adolescents (n = 157), and three focus groups with mothers of 11- to 18-year-olds were conducted to assess knowledge, attitudes, and barriers related to recommended adolescent vaccines. Bivariate analyses of parent survey responses were performed to evaluate possible differences between ethnic groups (chi-square test and Fisher exact test where possible). Findings were used to develop (1) culture-specific written brochures for community members, which addressed misperceptions about adolescent immunizations and related diseases, and (2) a presentation highlighting specific messages for health care providers (HCPs) in the target communities. HCPs were surveyed after delivery of the presentation (n = 20).

RESULTS

We identified barriers to adolescent immunization including: parents' and adolescents' limited awareness of, and misperceptions regarding, recommended adolescent vaccines and vaccine preventable diseases; lack of HCP recommendations for vaccination; and inability to access health information in native languages. Awareness of tetanus, diphtheria, and acellular pertussis, quadrivalent meningococcal conjugate, and human papillomavirus vaccines varied by vaccine and ethnic group. Lack of knowledge of adolescent vaccination recommendations was the main reason given by parents that their adolescents had not been vaccinated. Most parents in the focus groups identified doctors as a trusted source of health information and reported that they would vaccinate their teens if their doctor recommended it. All the surveyed HCPs routinely recommend adolescent vaccines at well-child visits, 55% at acute visits, and 35% at injury visits. Eighty percent reported that they would be more likely to recommend HPV vaccine after our on-site presentation.

CONCLUSIONS

A strong recommendation from the physician is a critical factor influencing parents' decision to vaccinate, even when hesitancy exists. Other factors (such as personal experiences with these diseases and religious and cultural beliefs) also influence parents' decisions regarding vaccination. Knowledge of beliefs, misperceptions, and concerns can help inform strategies to improve adolescent vaccine uptake among specific ethnic populations, including the availability of culturally tailored, translated information. Additionally, HCPs may benefit from guidance on communicating with ethnic populations to support meaningful dialogue with families about the risks and benefits of adolescent vaccines.

Serologic evidence of pertussis infection in vaccinated Iranian children

BACKGROUND

It seems that the incidence of pertussis-like illnesses is considerably increasing despite the wide coverage of immunization with the whole cell pertussis vaccine. We aimed to investigate the occurrence of pertussis in vaccinated children by measuring anti-pertussis antibodies.

METHODS

In this cross-sectional study, blood samples were taken from vaccinated children aged 2, 4, 6, 12, 18, and 72 months. Anti-pertussis IgG and IgA were measured by ELISA. P<0.05 was considered significant.

RESULTS

725 children were enrolled in the study. Geometric mean titers for IgG that showed a slight decease after 2 months of age and increased distinctly in children aged 72 months. The frequency of the individuals whose IgG was above the determined cut-off (derived from mean+2SD) was observed in 1% of the 2, 4, and 6-month-old infants, 6% of the 12 and 18-month-olds and 12% of the 6-year -old children. Positive IgA titers were detected in 5, 9, 6, 23, 11, and 8% of children aged 2, 4, 6, 12, 18, and 72 months, respectively.

CONCLUSION

Since a considerable percentage of children had high levels of anti-pertussis IgG antibodies (≥2 SD), positive anti-pertussis IgA, and most importantly an increased level of anti-pertussis IgG geometric mean titer at 6 years of age, further investigations regarding the protection provided by the presently used pertussis vaccine seems necessary.