Pregnancy dose Tdap and postpartum cocooning to prevent infant pertussis: a decision analysis

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.

The current state of pertussis vaccination in pregnancy around the world, with recommendations for improved care: Consensus statements from the Global Pertussis Initiative

Bordetella pertussis, which causes a respiratory disease known as pertussis ("whooping cough") remains an important global challenge, with the incidence in pertussis cases increasing in recent years. Newborns and infants are at increased risk for severe morbidity and mortality from this bacterium. Vaccination in pregnancy has become an important strategy to both passively transfer immunity as well as prevent infection in pregnant persons, who are a major source of newborn infection, thus attempting to decrease the impact of this serious disease. It is considered safe for the pregnant person, the developing fetus, and the infant, and during the first 3 months of life it has been shown to be highly effective in preventing pertussis. There are a variety of strategies, recommendations, and adherence rates associated with pertussis vaccination in pregnancy around the world. We summarize the 2021 Global Pertussis Initiative Annual Meeting that reviewed the current global status of pertussis vaccination in pregnancy and remaining medical and scientific questions, with a focus on vaccination challenges and strategies for obstetric and gynecologic healthcare providers.

Society for Maternal-Fetal Medicine Statement: Clinical considerations for the prevention of respiratory syncytial virus disease in infants

Respiratory syncytial virus is a leading cause of lower respiratory tract illness globally in children aged <5 years. Each year, approximately 58,000 hospitalizations in the United States are attributed to respiratory syncytial virus. Infants aged ≤6 months experience the most severe morbidity and mortality. Until recently, prevention with the monoclonal antibody, palivizumab, was only offered to infants with high-risk conditions, and treatment primarily consisted of supportive care. Currently, 2 products are approved for the prevention of respiratory syncytial virus in infants. These include the Pfizer bivalent recombinant respiratory syncytial virus prefusion F protein subunit vaccine, administered seasonally to the pregnant person between 32 0/7 and 36 6/7 weeks of gestation, and the monoclonal antibody, nirsevimab, administered to infants aged up to 8 months entering their first respiratory syncytial virus season. With few exceptions, administering both the vaccine to the pregnant person and the monoclonal antibody to the infant is not recommended. All infants should be protected against respiratory syncytial virus using one of these strategies. Key considerations for pregnant individuals include examining available safety and efficacy data, weighing accessibility and availability, and patient preferences for maternal vaccination vs infant monoclonal antibody treatment. It will be critical for maternal-fetal medicine physicians to provide effective and balanced counseling to aid patients in deciding on a personalized approach to the prevention of respiratory syncytial virus in their infants.

The Present and Future Aspects of Life-Long Pertussis Prevention: Narrative Review with Regional Perspectives for Türkiye

Pertussis, caused by Bordetella pertussis, remains one of the most widespread, contagious, and vaccine-preventable diseases. It results in notable morbidity and mortality as well as severe medical, social, and economic burden. Despite high global vaccine coverage, pertussis continues to be a significant epidemiologic problem, with outbreak episodes every few years just as in the pre-vaccination era. In Türkiye, there is a lack of comprehensive data on the current burden of pertussis in different age and risk groups, leading to underdiagnosis and underreporting of the disease, especially in adults who are often not considered at risk. Available data from Türkiye also reveal inadequate levels of protective antibodies in preterm newborns, emphasizing the need for additional preventive measures. Authors stated that improving physician awareness of pertussis symptoms in patients with prolonged cough, increasing access to routine pertussis tests, and conducting surveillance studies would aid in accurate diagnosis and reporting in Türkiye. As the Turkish Ministry of Health Antenatal Care Management Guide suggests routine second and third pregnancy check-up visits at weeks 18-24 and 28-32 correspondingly, this period can be considered the ideal vaccination time for Türkiye. Introducing a booster dose of Tdap at around 10 years of age or during national military service would reduce transmission and protect susceptible individuals. Identifying individuals at high risk of severe pertussis and prioritizing them for a booster dose is also crucial in Türkiye. Enhancing surveillance systems, increasing healthcare professionals' awareness through training, and organizing catch-up visits for missed vaccinations during the COVID-19 pandemic are mentioned as additional strategies to improve pertussis prevention in Türkiye. This review focuses on the global and regional burden of pertussis and obstacles to effective prevention and evaluates existing strategies to achieve lifelong pertussis prevention. Literature and current strategies were also discussed from a Turkish national standpoint.

[Prevention of pertussis in newborns: Should pregnant women be vaccinated at each pregnancy?]

Pertussis is a respiratory disease that can be fatal at all ages but especially in infants before their mandatory vaccination. Recent epidemiological data shows a decrease in the number of pertussis cases, but a resurgence cannot be excluded in the coming years due to the cyclic evolution of the disease and the loosening of hygiene measures. Two approaches are used to protect infants before their vaccination: vaccination of the mother during pregnancy and vaccination of all the infant's close relatives (cocooning). The vaccination of the mother during pregnancy is more effective. The uncertain risk of chorioamniotitis associated with vaccination during pregnancy is insufficient to question this strategy.

Coping Strategies for Pertussis Resurgence

Pertussis (whooping cough) is a respiratory disease caused primarily by Bordetella pertussis, a Gram-negative bacteria. Pertussis is a relatively contagious infectious disease in people of all ages, mainly affecting newborns and infants under 2 months of age. Pertussis is undergoing a resurgence despite decades of high rates of vaccination. To better cope with the challenge of pertussis resurgence, we evaluated its possible causes and potential countermeasures in the narrative review. Expanded vaccination coverage, optimized vaccination strategies, and the development of a new pertussis vaccine may contribute to the control of pertussis.

Universal Tetanus-Diphtheria-Pertussis Vaccination During Pregnancy: A Cost-Effectiveness Analysis

OBJECTIVE

To assess the cost effectiveness of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination in pregnant patients in the United States.

METHODS

A decision-analytic model in TreeAge was developed to compare universal Tdap vaccination in pregnancy with no Tdap vaccination in pregnancy using a theoretical cohort of 3.66 million pregnant individuals, the approximate number of deliveries per year in the United States. Outcomes included infant pertussis infections, infant hospitalizations, infant encephalopathy cases, infant deaths, and maternal pertussis infections. All probabilities and costs were derived from the literature. Utilities were applied to discounted life expectancies at a rate of 3% to generate quality-adjusted life-years (QALYs). A strategy was considered cost effective if it had an incremental cost-effectiveness ratio of less than $100,000 per QALY. Univariable and multivariable sensitivity analyses were performed to assess the robustness of the model to changes in the baseline assumptions.

RESULTS

With a baseline assumption of vaccine cost at $47.75, Tdap vaccination was cost effective at $7,601 per QALY. The vaccination strategy was associated with a decrease of 22 infant deaths, 11 infant encephalopathy cases, 2,018 infant hospitalizations, 6,164 infant pertussis infections, and 8,585 maternal pertussis infections, with an increase of 19,489 QALYs. In sensitivity analyses, the strategy was cost effective until the incidence of maternal pertussis became lower than 1.6 cases per 10,000 individuals, the cost of the Tdap vaccine was greater than $540, or previous pertussis immunity was present in more than 92.1% of pregnant individuals.

CONCLUSION

In a theoretical U.S. cohort of 3.66 million pregnant individuals, Tdap vaccination during pregnancy is cost effective and reduces infant morbidity and mortality compared with no vaccination during pregnancy. These findings are especially relevant given that approximately half of individuals are not vaccinated during pregnancy and recent data have shown that postpartum maternal vaccination and cocooning strategies are ineffective. Public health strategies to encourage greater uptake of Tdap vaccination should be used to reduce the morbidity and mortality of pertussis infection.

Cost-Utility Analysis of Universal Maternal Pertussis Immunisation in Thailand: A Comparison of Two Model Structures

OBJECTIVES

This study aimed to assess the cost-effectiveness of introducing universal maternal pertussis immunisation under the national vaccine programme in Thailand.

METHODS

We conducted a cost-utility analysis from a societal perspective to compare maternal vaccination with (1) TdaP vaccine, (2) Td vaccine and aP vaccine, and (3) Td vaccine only. We constructed two decision-tree models with Markov elements, each following a different clinical pathway, to allow us to examine structural uncertainty. Costs were converted to 2021 Thai Baht (THB) and a discount rate of 3% was applied to health and cost outcomes, with sensitivity analysis at 0% and 6%. Parameter uncertainty was investigated through deterministic and probabilistic sensitivity analysis, with expected value of perfect information analysis.

RESULTS

Maternal pertussis vaccination would avert 27 cases and up to one death per year. The incremental cost-effectiveness ratio (ICER) for adding aP to the maternal immunisation schedule is 2,184,025 THB/QALY and the ICER for replacing maternal Td vaccination with TdaP is 3,198,101 THB/QALY. Maternal pertussis vaccination only becomes favourable in the probabilistic sensitivity analysis at cost-effectiveness thresholds above 6,000,000 THB/QALY, far above the Thai threshold of 160,000 THB/QALY. If incidence is less than 397 cases per 100,000, maternal pertussis vaccination will not be cost-effective in Thailand, within the plausible range for vaccine effectiveness and probability of hospitalisation. Budget impact is dominated by vaccination costs, which represent 12% and 18% of the 2021 national vaccine programme budget for introducing aP vaccine or for switching Td with TdaP vaccine, respectively.

CONCLUSIONS

We have found that maternal pertussis immunisation is not cost-effective in Thailand. Although there may be substantial under-reporting of pertussis cases, comparison with hospital data suggests that most under-reported cases are not hospitalised and therefore have negligible impact on our results. However, considerations such as affordability and local manufacturing may also be important for national immunisation programme decision-making.

Pertussis and influenza immunization: perceived attitude and decision of postpartum patients

BACKGROUND

Vaccination of pregnant patients with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) and influenza vaccine during influenza season can reduce maternal and fetal morbidity and mortality; nevertheless, vaccination rates remain suboptimal in this patient population. To investigate the effect of a brief educational counseling session on maternal Tdap and influenza vaccination and determine factors influencing women's decision in regards to receiving Tdap and or influenza vaccine during their pregnancy.

METHODS

A face-to-face semi-structured cross-sectional survey was administered to postpartum patients on their anticipated day of discharge (June 11-August 21, 2018). A brief educational counseling session about maternal pertussis and Tdap vaccine was provided to interested patients after which the Tdap vaccine was offered to eligible patients who did not receive it during their pregnancy or upon hospital admission. Medical records were reviewed to determine if surveyed patients were vaccinated prior to discharge.

RESULTS

Two hundred postpartum patients were surveyed on their day of anticipated discharge. Of those who were surveyed, 103 (51.5%) had received Tdap and 80 (40.0%) had received influenza vaccinations prior to hospitalization. Among immunized patients, the common facilitators were doctor's recommendation (Tdap: 68, 54.4%; influenza: 3, 6.0%), to protect their baby (Tdap: 57, 45.6%; influenza: 17, 34.0%) and for self-protection (Tdap: 17, 13.6%; Influenza: 17, 34.0%). Of the 119 participants who had not received either Tdap or influenza vaccine prior to the survey, the barriers cited were that the vaccine was not offered by the provider (Tdap: 36, 52.2%; influenza: 29, 27.6%), belief that vaccination was unnecessary (Tdap: 5, 7.2%; influenza: 9, 8.5%), safety concerns for baby (Tdap: 4, 5.8%; influenza: 2, 1.9%). Of 97 patients who were not immunized with Tdap prior to admission but were eligible to receive vaccine, 24 (25%) were vaccinated prior to survey as part of routine hospital-based screening and vaccination program, 29 (38.2%) after our survey.

CONCLUSION

Interventions to educate pregnant patients about the benefits of vaccination for their baby, addressing patient safety concerns, and vaccine administration in obstetricians' offices may significantly improve maternal vaccination rates.

Intention and Attitude to Accept a Pertussis Cocooning Vaccination among Chinese Children's Guardians: A Cross-Sectional Survey

OBJECTIVE

to assess Chinese children's guardians' intentions and attitudes toward accepting a pertussis cocooning vaccination and its determinants.

METHODS

a self-administered questionnaire was designed based on a theoretical framework that originated mainly from the reasoned action approach. Associations between questionnaire variables and outcomes were assessed using univariate and multivariate analyses with odds ratios (OR), regression coefficients (β), and their 95% confidence intervals (CIs).

RESULTS

among 762 eligible participants, most (80.71%) reported a positive intention to accept a pertussis cocooning vaccination. The guardians' positive intention was related to the children's pertussis vaccination experience (OR = 2.483, 95% CI: 1.340-4.600). Guardians who had a positive attitude towards pertussis vaccination (OR = 1.554, 95% CI: 1.053-2.296), higher subjective norms (OR = 1.960, 95% CI: 1.371-2.802) and better perceived behavioral control (OR = 7.482, 95% CI: 4.829-11.591) stated a higher intention to receive a pertussis cocooning vaccination. The mean attitude score was 3.88 ± 0.863. Greater risk perception about pertussis (β = 0.390, 95% CI: 0.298-0.483), stronger obligation from moral norms (β = 0.355, 95% CI: 0.279-0.430), and good knowledge (β = 0.108, 95% CI: 0.070-0.146) were significantly related to positive attitude toward pertussis cocooning vaccination among guardians.

CONCLUSIONS

Chinese children's guardians held positive intentions and attitudes toward accepting a pertussis cocooning vaccination. The current findings described the determinants of such intention and attitude and provided knowledge based on improving guardians' intentions for policymakers if cocooning vaccinations or related immunization strategies are implemented in China in the future.

Strategies to increase uptake of maternal pertussis vaccination

INTRODUCTION

Pertussis is a highly contagious respiratory disease that results in disproportionate morbidity and mortality in infants who have yet to receive the primary diphtheria-tetanus-pertussis vaccine series. In the preceding decades numerous countries began to pursue either prenatal vaccination of pregnant women or postpartum vaccination of caregivers to protect infants. Despite proven benefit, maternal uptake of pertussis vaccine continues to remain suboptimal.

AREAS COVERED

Many studies have been conducted to address the suboptimal uptake of maternal pertussis vaccination. This systematic review was undertaken to systematically identify those studies, highlight the most successful strategies and find the knowledge gaps that need to be filled over the coming years to improve vaccine uptake. Twenty-five studies were identified from six different databases.

EXPERT OPINION

Five different interventions were shown to be successful in promoting uptake of pertussis vaccination: (1) standing orders, (2) opt-in orders, (3) provider education, (4) on-site vaccination and (5) interactive patient education. Three major knowledge gaps were also identified that need to be filled over the coming years: (1) lack of studies in low- and middle-income countries, (2) lack of studies targeting midwives and/or home birth and (3) lack of studies on the process of vaccine communication.

Effect of a postpartum prescription for pertussis vaccine: a before-and-after study

BACKGROUND

Among the strategies to encourage pregnant women to be vaccinated against pertussis in the postpartum period, that of giving them a prescription has been evaluated only sparsely.

OBJECTIVE

To measure the effect of giving women who are not immunized against pertussis a prescription for the vaccine at discharge from the maternity unit.

MATERIAL AND METHODS

Single-center before-and-after study (2011: before; 2015: after). All women received both oral and written information about vaccination against pertussis. During the after period, they were also specifically asked their immunization status during pregnancy. Those currently unimmunized received a written prescription for it at discharge.

RESULTS

Among the women unimmunized at delivery, the percentage who were vaccinated postpartum climbed from 17 to 42% between 2011 and 2015 (p < 0.001), while the percentage of their unimmunized partners who were vaccinated remained stable (27 and 29%, p = 0.74). During this time, the percentage of women immunized against pertussis at the beginning of pregnancy rose from 32 to 52% (p < 0.001). Finally, the percentage of all women protected against this disease postpartum climbed from 44 to 72% between these two periods (p < 0.001).

CONCLUSIONS

In the postpartum period, giving a prescription for pertussis vaccine to women unimmunized is accompanied by a significant elevation in their vaccination rate. Nevertheless, this rate remains low and better strategies have to be implemented.

Pertussis vaccination in pregnancy in Canada: a cost-utility analysis

BACKGROUND

The Canadian National Advisory Committee on Immunization recommends universal vaccination against pertussis in pregnancy. We assessed the cost-effectiveness of vaccination with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy in Canada.

METHODS

We conducted a cost-utility analysis comparing a vaccination program to no program corresponding with the 2017 Canadian guideline for economic evaluation from the Canadian Agency for Drugs and Technologies in Health. We developed 2 models - part decision tree, part Markov model - to estimate the long-term cost and quality-adjusted life-years (QALYs) for pregnant women and their infants. We obtained epidemiologic data from 2006 to 2015, and derived costs and utility values from relevant sources. Results were reported in 2019 Canadian dollars. We obtained expected values through probabilistic analysis, with methodologic and structural uncertainty assessed through scenario analyses. The analysis adopted an acquisition price of Tdap vaccine of $12.50, with scenario analysis conducted to identify the threshold price for vaccination to be cost-effective.

RESULTS

In the base-case scenario, for every 1000 pregnant women vaccinated, the program would lead to a gain of 0.3 QALYs, occurring solely in infants, at an increased total cost of $12 987, or $44 301 per QALY gained. Based on a threshold of $50 000 per QALY gained, vaccination would have been cost-effective in 6 of the 10 years included in the model (range of incremental costs $20 463-$100 348 per QALY gained). The threshold cost for Tdap vaccine to be cost-effective over the 10-year horizon was $14.03.

INTERPRETATION

Based on a threshold of $50 000 per QALY gained, vaccination against pertussis in pregnancy would be cost-effective if the acquisition cost per vaccine were $14.03 or less. Province- and territory-specific analyses should be done to inform local decision-making.

A review of the costs of delivering maternal immunisation during pregnancy

Background

Routine maternal immunisation against influenza and pertussis are recommended by the WHO to protect mother and child, and new vaccines are under development. Introducing maternal vaccines into national programmes requires an understanding of vaccine delivery costs – particularly in low resource settings.

Methods

We searched Medline, Embase, Econlit, and Global Health for studies reporting costs of delivering vaccination during pregnancy but excluded studies that did not separate the vaccine purchase price. Extracted costs were inflated and converted to 2018 US dollars.

Results

Sixteen studies were included, of which two used primary data to estimate vaccine delivery costs. Costs per dose ranged from $0.55 to $0.64 in low-income countries, from $1.25 to $6.55 for middle-income countries, and from $5.76 to $39.87 in high-income countries.

Conclusions

More research is needed on the costs of delivering maternal immunisation during pregnancy, and of integrating vaccine delivery into existing programmes of antenatal care especially in low and middle-income countries.

Effectiveness of strategies to increase uptake of pertussis vaccination by new parents and family caregivers: A systematic review

OBJECTIVES

Cocoon immunisation strategies involve administration of Bordetella pertussis containing vaccines to parents and family members who are in close contact with newborns. The objective of this systematic review was to evaluate the effectiveness of strategies to increase uptake of vaccination against Bordetella pertussis infection by parents and family caregivers of newborn children (< 3 months of age).

DESIGN

A protocol driven systematic review was conducted between 2005 and February 2020. CINAHL, Medline, and Google Scholar databases were searched.

SETTING

Inpatient maternity care units, ante-natal and post-natal clinics based in acute care or primary/community care contexts.

PARTICIPANTS

(i) mothers, (ii) fathers and (iii) family caregivers or other regular household contacts of infants < 3 months of age.

INTERVENTIONS

Health promotion interventions and immunisation clinics designed to promote "cocoon immunisation" against Bordetella pertussis infections of the newborn.

MEASUREMENTS

Change in uptake of adult vaccination with a pertussis containing vaccine (dTpa or Tdap) by new parents and family caregivers.

FINDINGS

Eight studies were included in this review. Strategies used to promote vaccination included: written and verbal education, promotional videos, provision of vaccine prescriptions and financial incentives, opportunistic vaccination of family members and population-based health promotional messaging. Six of the eight studies reported positive impacts on vaccination uptake. Four studies evaluating providing opportunistic immunisation during the obstetric admission reported statistically significant increases in maternal (+39% to +57%), paternal (+21% to +52%) and household members (+32%) vaccination rates. Targeted public health campaigns were also found to increase vaccination uptake but in isolation were insufficient to achieve vaccination of all household contacts.

CONCLUSION

Promotion of pertussis vaccination to new parents and the provision of opportunistic vaccination during the obstetric admission or post-natal visit, was the most successful strategy to increase uptake of pertussis vaccination by family caregivers.

Tetanus, diphtheria and acellular pertussis (Tdap) vaccine for prevention of pertussis among adults aged 19 years and older in the United States: A cost-effectiveness analysis

Currently, the Advisory Committee on Immunization Practices recommends one-time tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination for all adults 19 years and older. This study is designed to evaluate the cost-effectiveness of Tdap vaccination for Tdap-eligible adults aged 19 through 85 in the United States. A cost-effectiveness model was developed to compute costs and health outcomes associated with pertussis among 100,000 Tdap-eligible persons of each age cohort. From the societal perspective, the cost per quality-adjusted life-year (QALY) saved was evaluated under the vaccination scenarios. Sensitivity analyses were also conducted to evaluate the impacts of changes in key variables. All costs were adjusted to 2018 US$ with an annual discount rate of 3% applied to costs and outcomes. The incremental cost-effectiveness ratios (ICERs) for vaccinating US adults aged 19 to 85 with Tdap ranged from $248,000/QALY to $900,000/QALY. The lowest cost per QALY was found to be $248,000 for the age 65 cohort, followed by $332,000 for the cohort of age 19, and followed by $477,000 for the age 50 cohort. Sensitivity analysis showed the most dramatic changes in ICER occurred when changing the underreporting factor, vaccine effectiveness and vaccination costs. While Tdap vaccination may not be as cost effective as predicted earlier, it remains the best available preventive measure against pertussis. Further investigation of the true burden of pertussis disease among adults and the effectiveness of Tdap vaccination in this population is needed to better estimate the impact of Tdap vaccination.

Impact of Pertussis on the Italian population: Analysis of hospital discharge records in the period 2001-2014

OBJECTIVES

The study aimed to analyze and update the impact of pertussis on the Italian population by evaluating pertussis-related hospital admissions in the period 2001-2014.

DESIGN OR METHODS

Hospital Discharge Records (HDR) were provided by the National Archive of HDR data of the Ministry of Health. Only hospitalizations included in the primary diagnosis were evaluated. Significant trends over the considered years were assessed as average annual percent changes (AAPC) applying the Joinpoint model.

RESULTS

A total of 7,102 hospital admissions for pertussis (main diagnosis) were registered; the trend of hospitalizations progressively decreased from >1/100,000 inhabitants in the years 2001-2004 to 0.64/100,000 inhabitants in 2014. A great part of hospitalizations (63.6%) involved subjects <1 year of life; almost 20% of cases were registered in the age class 5-14 years. The Joinpoint analysis showed a statistically significant variation in some age classes.

CONCLUSIONS

Even if this study shows a decreasing trend in the number of pertussis-related hospitalizations, the impact of the disease in Italy in terms of hospital admissions continues to be relevant, especially in the <1 year age class. Pertussis therefore continues to be, in Italy as well as in other European countries, an important public health issue.

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.

Trends in Tdap vaccination among privately insured pregnant women in the United States, 2009-2016

BACKGROUND

Infants younger than 6 months are at increased risk of complications and mortality from pertussis infection. In October 2012, the Advisory Committee on Immunization Practices revised its recommendation to include a Tdap dose during each pregnancy, ideally between 27 and 36 weeks gestation.

OBJECTIVE

Assess trends in Tdap vaccination coverage among privately insured pregnant women from 2009 to 2016 including timing of Tdap vaccination (before, during, or after pregnancy), trimester of vaccination for women vaccinated during pregnancy, and missed vaccination opportunities for unvaccinated women. Identify factors associated with vaccination during the optimal period of 27-36 weeks gestation.

STUDY DESIGN

Retrospective analysis of privately insured women 15-49 years who delivered live births during 2009-2016 conducted using 2009-2016 MarketScan data. Tdap vaccination coverage and the timing of Tdap vaccine administration were assessed for women continuously enrolled from 6 months before pregnancy to 1 month after delivery. Multivariable logistic regression was performed to identify factors independently associated with receipt of Tdap vaccine at 27-36 weeks gestation.

RESULTS

Tdap vaccination coverage during pregnancy increased from 0.4% in 2009 to 6.2% in 2012 and to 53.2% in 2016. The proportion of vaccinated women receiving Tdap at 27-36 weeks gestation increased from <10% in 2009 to nearly 90% in 2016, with most vaccination occurring at 27-32 weeks gestation. Women of older age, residing in a metropolitan statistical area, residing outside the South, and having a capitated health insurance plan were more likely to receive Tdap at 27-36 weeks gestation than their counterparts. Among women not vaccinated during pregnancy, 77.7% had a pregnancy-related medical claim between 27 and 36 weeks gestation.

CONCLUSION

Tdap vaccination coverage during pregnancy increased significantly from 2009 to 2016, with the greatest increase occurring after the revised Advisory Committee on Immunization Practices recommendation. Most women who did not receive Tdap vaccine had a missed vaccination opportunity during pregnancy, indicating potential for much higher vaccination coverage and consequent infant protection against pertussis.

Effectiveness of dTpa vaccination during pregnancy in preventing whooping cough in infants under 3 months of age. Bizkaia, Basque Country, Spain

In response to an increase in the incidence of whooping cough in recent years, the Basque Country established a vaccination programme for pregnant women in the last trimester of the pregnancy seeking to protect young infants, a population that is at high risk of developing severe whooping cough. In the present study, based on the screening method, we assessed the effectiveness of this measure to prevent whooping cough in infants under 3 months of age. We found a vaccine effectiveness of 89% and 95% CI 72-96%. While the incidence of this disease remains high, we recommend continuing to vaccinate pregnant women in the last trimester of pregnancy.

Neonatal Immunity to Bordetella pertussis Infection and Current Prevention Strategies

Bordetella pertussis is the bacterial agent of whooping cough, an infectious disease that is reemerging despite high vaccine coverage. Newborn children are the most affected, not only because they are too young to be vaccinated but also due to qualitative and quantitative differences in their immune system, which makes them more susceptible to infection and severe manifestations, leading to a higher mortality rate comparing to other groups. Until recently, prevention consisted of vaccinating children in the first year of life and the herd vaccination of people directly in touch with them, but the increase in cases demands more effective strategies that can overcome the developing immune response in early life and induce protection while children are most vulnerable.

Pertussis: New preventive strategies for an old disease

In the last twenty years, despite high vaccination coverage, epidemics of pertussis are occurring in both developing and developed countries. Many reasons could explain the pertussis resurgence: the increasing awareness of the disease, the availability of new diagnostic tests with higher sensitivity, the emergence of new Bordetella pertussis (B. pertussis) strains different from those contained in the current vaccines, the asymptomatic transmission of B. pertussis in adolescents and adults and the shorter duration of protection given by the acellular pertussis (aP) vaccine. New preventive strategies have already been implemented, such as booster doses of aP vaccine in adolescents and adults, maternal immunisation during pregnancy and the "cocooning" strategy, but more are still needed. Knowing what is new about this old disease is necessary to reduce its incidence and to protect infants too young to be vaccinated, which have the highest risk of complications and death.

Economic evaluation of adolescents and adults' pertussis vaccination: A systematic review of current strategies

The reemergence of pertussis in the last two decades led to the introduction of adolescents and adults immunization strategies of tetanus–diphtheria–acellular pertussis vaccines (Tdap) in several countries. The health authorities must consider economic aspects when deciding to recommend and fund new programs. Here we present a systematic review of worldwide full economic evaluations of pertussis vaccination targeting adolescents or adults published from 2000. Studies were identified by searching MEDLINE, Excerpta Medica, CRD, and Lilacs databases. Twenty-seven economic evaluations of different strategies with Tdap were identified. Booster vaccination for adolescents and adults were the most frequent, followed by cocooning and pregnant women vaccination. Strategies performance varied considerably among different studies. Assumptions regarding underreporting correction, herd protection and vaccine coverage were crucial to cost-effectiveness results. Understanding the model and the parameters used is essential to understand the results, and identify the major issues important to public health decisions.

Is adding maternal vaccination to prevent whooping cough cost-effective in Australia?

Pertussis or whooping cough, a highly infectious respiratory infection, causes significant morbidity and mortality in infants. In adolescents and adults, pertussis presents with atypical symptoms often resulting in under-diagnosis and under-reporting, increasing the risk of transmission to more vulnerable groups. Maternal vaccination against pertussis protects mothers and newborns. This evaluation assessed the cost-effectiveness of adding maternal dTpa (reduced antigen diphtheria, Tetanus, acellular pertussis) vaccination to the 2016 nationally-funded pertussis program (DTPa [Diphtheria, Tetanus, acellular Pertussis] at 2, 4, 6, 18 months, 4 years and dTpa at 12–13 years) in Australia.

A static cross-sectional population model was developed using a one-year period at steady-state. The model considered the total Australian population, stratified by age. Vaccine effectiveness against pertussis infection was assumed to be 92% in mothers and 91% in newborns, based on observational and case-control studies. The model included conservative assumptions around unreported cases.

With 70% coverage, adding maternal vaccination to the existing pertussis program would prevent 8,847 pertussis cases, 422 outpatient cases, 146 hospitalizations and 0.54 deaths per year at the population level. With a 5% discount rate, 138.5 quality-adjusted life-years (QALYs) would be gained at an extra cost of AUS$ 4.44 million and an incremental cost-effectiveness ratio of AUS$ 32,065 per QALY gained. Sensitivity and scenario analyses demonstrated that outcomes were most sensitive to assumptions around vaccine effectiveness, duration of protection in mothers, and disutility of unreported cases.

In conclusion, dTpa vaccination in the third trimester of pregnancy is likely to be cost-effective from a healthcare payer perspective in Australia.

Maternal immunization: where are we now and how to move forward?

Pregnancy and the postpartum period are associated with elevated risks to both mother and infant from infectious disease. Vaccination of pregnant women, also called maternal immunization, has the potential to protect pregnant women, foetuses and infants from several vaccine-preventable diseases. Maternal immunoglobulin G antibodies are actively transferred through the placenta to provide passive immunity to new-borns during the first months of life, until the time for infant vaccinations or until the period of greatest susceptibility has passed. Currently, inactivated influenza, tetanus, and pertussis vaccines are recommended during pregnancy in many countries, but other vaccines may also be administered to pregnant women when risk factors are present. Several new vaccines with a specific indication for use during pregnancy are under development (e.g. respiratory syncytial virus and group B streptococcus vaccines). Years of experience suggest that maternal immunization against influenza, tetanus or pertussis has an acceptable safety profile, is well tolerated, effective and confers significant benefits to pregnant women and their infants. This review describes the principles of maternal immunization and provides an update of the recent evidence regarding the use and timing of maternal immunization. Finally, the barriers preventing wider vaccination coverage and the current limitations in addressing these are also described ( Supplementary Material ). Key messages Maternal immunization gives pregnant women greater protection against infectious diseases; induces high levels of maternal antibodies that can be transferred to the foetus; and helps protect new-borns during their first months of life, until they are old enough to be vaccinated. Pregnant women and new-borns are more vulnerable to infectious diseases than the overall population; nevertheless, vaccination rates are often low in pregnant women. This review provides an update of the recent evidence regarding the use and timing of maternal immunization and describes the barriers preventing wider vaccination uptake and the current limitations in addressing these.

Prevention of Pertussis, Tetanus, and Diphtheria with Vaccines in the United States: Recommendations of the Advisory Committee on Immunization Practices (ACIP)

This report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) regarding prevention and control of tetanus, diphtheria, and pertussis in the United States. As a comprehensive summary of previously published recommendations, this report does not contain any new recommendations and replaces all previously published reports and policy notes; it is intended for use by clinicians and public health providers as a resource. ACIP recommends routine vaccination for tetanus, diphtheria, and pertussis. Infants and young children are recommended to receive a 5-dose series of diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccines, with one adolescent booster dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. Adults who have never received Tdap also are recommended to receive a booster dose of Tdap. Women are recommended to receive a dose of Tdap during each pregnancy, which should be administered from 27 through 36 weeks' gestation, regardless of previous receipt of Tdap. After receipt of Tdap, adolescents and adults are recommended to receive a booster tetanus and diphtheria toxoids (Td) vaccine every 10 years to assure ongoing protection against tetanus and diphtheria.

"When you are injected, the baby is protected:" Assessing the acceptability of a maternal Tdap vaccine based on mothers' knowledge, attitudes, and beliefs of pertussis and vaccinations in Lusaka, Zambia

INTRODUCTION

Severe and fatal pertussis infections are concentrated among infants who are too young to be protected through routine vaccinations. Maternal Tdap (mTdap), which is now the standard of care in the US and UK, is considered to be the most effective way to address this gap in preventative care. Little is known about how pregnant women in low-resource settings might view mTdap. To inform strategies for mTdap implementation in these contexts, public health researchers sought to understand knowledge, attitudes, and beliefs toward pertussis and maternal vaccines and assess the barriers to vaccine acceptance.

METHODS

We conducted focus group discussions (FGDs) among mothers who participated in a longitudinal birth cohort study at the Chawama primary health center in Lusaka, Zambia. Since SAMIPS was not a clinical trial, but instead an observational cohort study, registration on clinicaltrials.gov was not required. Trained interviewers conducted the FGDs in January 2016 using a semi-structured interview guide, exploring participants' knowledge, attitudes and beliefs toward pertussis and vaccines. We analyzed the transcripts using Nvivo v.11 software.

RESULTS

Fifty mothers participated across 7 FGDs. Mothers had limited knowledge of pertussis and vaccines, yet expressed generally positive views of vaccinating themselves and their children. Participants conveyed very little vaccine hesitancy around maternal vaccinations, and discussed how they could protect their children's health. Mothers also highlighted barriers and facilitators to vaccine uptake, which included partner involvement, feelings of maternal authority over healthcare decision-making, and community rumors about Western medicine.

CONCLUSION

Mothers viewed vaccinations as an important method to keep their children healthy, despite cultural myths and misconceptions about pertussis and vaccines. FGD results suggest that vaccine acceptability is high in Zambia, which is a critical factor to vaccine uptake. A strategy addressing myths and misconceptions should be prioritized if and when mTdap is introduced across low-resource settings.

The importance of involving midwives before and during the implementation of an antenatal pertussis vaccination program in New South Wales, Australia

PROBLEM

Typically there is limited opportunity for stakeholder engagement to determine service delivery gaps when implementing an outbreak or supplementary vaccination program.

BACKGROUND

In response to increasing pertussis notifications in NSW, Australia, an antenatal pertussis vaccination program was introduced offering pertussis containing vaccine to all pregnant women in the third trimester.

AIM

To explore the effectiveness of consulting with midwives prior to and during a new state-wide vaccination program.

METHODS

A pre-program needs analysis was conducted through an online audit of the NSW Clinical Midwifery Consultants followed by a post-implementation audit at 18 months.

FINDINGS

Information received from the midwives was utilised during program planning which facilitated program implementation without any major issues in all Local Health Districts. The post-implementation audit provided feedback to program planners that that implementation was continuing consistently and Midwives were found to be very supportive and engaged.

DISCUSSION

Education and support of clinicians is vital for high vaccine uptake in new vaccination programs which can be enabled through appropriate educational packages and program resources.

CONCLUSION

Consulting with the midwives in advance of a new vaccination program was a new initiative and highly recommended as it was time well spent gaining essential information on program resourcing and operational needs. Conducting a post-implementation audit is also strongly recommended as a check-point for issues and recommendations, to empower frontline staff and support consistent program implementation. Frontline staff engagement before and during implementation of a new vaccination program is a powerful mechanism for effective, efficient and consistent program delivery.

Administration Rates of the Tdap Vaccine in Obstetric Patients

Background: Infants younger than 6 months of age are at high risk for contracting pertussis because of not being fully vaccinated. The Advisory Committee on Immunization Practices (ACIP) recommends vaccinating all pregnant women with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) between 27 and 36 weeks to offer passive immunity to the infant to help protect them until they are able to receive the full pertussis series. Objective: To assess and compare compliance with the 2013 ACIP recommendation of vaccinating pregnant women with Tdap at 27 to 36 weeks’ gestation in 2 obstetric clinics. Methods: This cross-sectional, retrospective chart review evaluated Tdap vaccine compliance in a random sample of obstetric patients from October 2013 to September 2014. The primary outcome evaluated the proportion of patients who received Tdap between 27 and 36 weeks’ gestation. Secondary outcomes included the proportion of patients who received Tdap at any point in pregnancy and within 30 days postpartum. Results: The charts of 573 patients were reviewed, and 237 met inclusion criteria. For the primary outcome, 142 patients (59.9%) received the Tdap vaccine. Overall, 156 patients (65.8%) received Tdap at some point during the pregnancy. Factors associated with receiving the Tdap vaccination were insurance status, prenatal care risk level and site of prenatal care, receipt of the influenza vaccine, and preterm labor in the current pregnancy. Conclusion: The Tdap vaccine rate was 65.8%, with 59.9% of patients receiving the vaccine within the recommended ACIP timeframe. Further education, improvements in documentation, and chart reminders are needed to enhance administration.

Bordetella pertussis

Pertussis is a highly infectious vaccine-preventable cough illness that continues to be a significant source of morbidity and mortality around the world. The majority of human illness is caused by Bordetella pertussis, and some is caused by Bordetella parapertussis. Bordetella is a Gram-negative, pleomorphic, aerobic coccobacillus. In the past several years, even countries with high immunization rates in early childhood have experienced rises in pertussis cases. Reasons for the resurgence of reported pertussis may include molecular changes in the organism and increased awareness and diagnostic capabilities, as well as lessened vaccine efficacy and waning immunity. The most morbidity and mortality with pertussis infection is seen in infants too young to benefit from immunization. Severe infection requiring hospitalization, including in an intensive care setting, is mostly seen in those under 3 months of age. As a result, research and public health actions have been aimed at better understanding and reducing the spread of Bordetella pertussis. Studies comparing the cost benefit of cocooning strategies versus immunization of pregnant women have been favorable towards immunizing pregnant women. This strategy is expected to prevent a larger number of pertussis cases, hospitalizations, and deaths in infants <1 year old while also being cost-effective. Studies have demonstrated that the source of infection in infants usually is a family member. Efforts to immunize children and adults, in particular pregnant women, need to remain strong.

Immune persistence after pertussis vaccination

Pertussis is one of the most prevalent vaccine-preventable diseases worldwide. The true infection rate is significantly higher than the reported incidence rate. An increased prevalence of pertussis in older populations has been found, mainly caused by waning immunity after vaccination. Vaccine-induced immunity differs due to variation in vaccine content, schedule and coverage. Protection following acellular pertussis vaccines has been suggested to wane faster than whole cell pertussis vaccines. However, long-term immune persistence of whole cell pertussis vaccines may be confounded by a progressive acquisition of natural immunity. The World Health Organization has recommended that a switch from whole cell to acellular pertussis vaccines for primary immunization in infants should only be considered if additional periodic boosters or maternal immunization can be ensured and sustained in the national immunization schedules. In this review, we present data on immune persistence after different pertussis vaccinations and compare the findings from countries with different vaccination strategies. Future aspects in serological studies are briefly discussed.

Incidence and Burden of Pertussis Among Infants Less Than 1 Year of Age

BACKGROUND

Infant-specific pertussis data, especially among neonates, are limited and variable. This study (NCT01890850) provides overall and age-specific pertussis incidence and associated health care utilization and costs among commercially insured infants in the US.

METHODS

Nearly 1.2 million infants born from 2005 to 2010 with commercial health plan coverage were followed during their first 12 months of life. Pertussis cases were identified from medical claims (International Classification of Diseases, 9th revision, Clinical Modification code: 033.0, 033.9, 484.3), and incidence rates were calculated. Each pertussis case was then matched to 10 comparators, so pertussis-related health care utilization and costs before and after the index date could be assessed.

RESULTS

The overall pertussis incidence rate among infants <12 months of age was 117.7/100,000 person-years; infants 3 months of age had the highest incidence rate (247.7/100,000 person-years). Infants diagnosed with pertussis were significantly more likely to have prior diagnoses of upper respiratory infection, cough and wheezing-related illnesses than comparators (P < 0.001). Pertussis cases were more likely to be hospitalized within 14 days after the index date (31.8% vs. 0.5%; P < 0.001) and their adjusted health care costs during follow-up were 2.82 times higher than comparators (P < 0.001; 95% confidence interval: 2.08-3.81). The incremental cost of pertussis during the 12-month follow-up period averaged $8271 (P < 0.001). The average incremental cost varied substantially by age, ranging from $18,781 (P < 0.001) to $3772 (P = 0.02) among infants 1 month and 7-12 months of age, respectively.

CONCLUSIONS

The health burden of pertussis, particularly in the youngest infants, remains substantial, highlighting the need to intensify efforts to protect this most vulnerable population.

Forecasting Epidemiological Consequences of Maternal Immunization

BACKGROUND

 The increase in the incidence of whooping cough (pertussis) in many countries with high vaccination coverage is alarming. Maternal pertussis immunization has been proposed as an effective means of protecting newborns during the interval between birth and the first routine dose. However, there are concerns regarding potential interference between maternal antibodies and the immune response elicited by the routine schedule, with possible long-term population-level effects.

METHODS

 We formulated a transmission model comprising both primary routine and maternal immunization. This model was examined to evaluate the long-term epidemiological effects of routine and maternal immunization, together with consequences of potential immune interference scenarios.

RESULTS

 Overall, our model demonstrates that maternal immunization is an effective strategy in reducing the incidence of pertussis in neonates prior to the onset of the primary schedule. However, if maternal antibodies lead to blunting, incidence increases among older age groups. For instance, our model predicts that with 60% routine and maternal immunization coverage and 30% blunting, the incidence among neonates (0-2 months) is reduced by 43%. Under the same scenario, we observe a 20% increase in incidence among children aged 5-10 years. However, the downstream increase in the older age groups occurs with a delay of approximately a decade or more.

CONCLUSIONS

 Maternal immunization has clear positive effects on infant burden of disease, lowering mean infant incidence. However, if maternally derived antibodies adversely affect the immunogenicity of the routine schedule, we predict eventual population-level repercussions that may lead to an overall increase in incidence in older age groups.

Cost-Effectiveness of Quadrivalent versus Trivalent Influenza Vaccine in the United States

BACKGROUND

Designed to overcome influenza B mismatch, new quadrivalent influenza vaccines (QIVs) contain one additional B strain compared with trivalent influenza vaccines (TIVs).

OBJECTIVE

To examine the expected public health impact, budget impact, and incremental cost-effectiveness of QIV versus TIV in the United States.

METHODS

A dynamic transmission model was used to predict the annual incidence of influenza over the 20-year-period of 2014 to 2034 under either a TIV program or a QIV program. A decision tree model was interfaced with the transmission model to estimate the public health impact and the cost-effectiveness of replacing TIV with QIV from a societal perspective. Our models were informed by published data from the United States on influenza complication probabilities and relevant costs. The incremental vaccine price of QIV as compared with that of TIV was set at US $5.40 per dose.

RESULTS

Over the next 20 years, replacing TIV with QIV may reduce the number of influenza B cases by 27.2% (16.0 million cases), resulting in the prevention of 137,600 hospitalizations and 16,100 deaths and a gain of 212,000 quality-adjusted life-years (QALYs). The net societal budget impact would be US $5.8 billion and the incremental cost-effectiveness ratio US $27,411/QALY gained. In the probabilistic sensitivity analysis, 100% and 96.5% of the simulations fell below US $100,000/QALY and US $50,000/QALY, respectively.

CONCLUSIONS

Introducing QIV into the US immunization program may prevent a substantial number of hospitalizations and deaths. QIV is also expected to be a cost-effective alternative option to TIV.

What Pertussis Mortality Rates Make Maternal Acellular Pertussis Immunization Cost-Effective in Low- and Middle-Income Countries? A Decision Analysis

BACKGROUND

 Despite longstanding infant vaccination programs in low- and middle-income countries (LMICs), pertussis continues to cause deaths in the youngest infants. A maternal monovalent acellular pertussis (aP) vaccine, in development, could prevent many of these deaths. We estimated infant pertussis mortality rates at which maternal vaccination would be a cost-effective use of public health resources in LMICs.

METHODS

 We developed a decision model to evaluate the cost-effectiveness of maternal aP immunization plus routine infant vaccination vs routine infant vaccination alone in Bangladesh, Nigeria, and Brazil. For a range of maternal aP vaccine prices, one-way sensitivity analyses identified the infant pertussis mortality rates required to make maternal immunization cost-effective by alternative benchmarks ($100, 0.5 gross domestic product [GDP] per capita, and GDP per capita per disability-adjusted life-year [DALY]). Probabilistic sensitivity analysis provided uncertainty intervals for these mortality rates.

RESULTS

 Infant pertussis mortality rates necessary to make maternal aP immunization cost-effective exceed the rates suggested by current evidence except at low vaccine prices and/or cost-effectiveness benchmarks at the high end of those considered in this report. For example, at a vaccine price of $0.50/dose, pertussis mortality would need to be 0.051 per 1000 infants in Bangladesh, and 0.018 per 1000 in Nigeria, to cost 0.5 per capita GDP per DALY. In Brazil, a middle-income country, at a vaccine price of $4/dose, infant pertussis mortality would need to be 0.043 per 1000 to cost 0.5 per capita GDP per DALY.

CONCLUSIONS

 For commonly used cost-effectiveness benchmarks, maternal aP immunization would be cost-effective in many LMICs only if the vaccine were offered at less than $1-$2/dose.

Effectiveness of Prenatal Versus Postpartum Tetanus, Diphtheria, and Acellular Pertussis Vaccination in Preventing Infant Pertussis

BACKGROUND

 Most severe and fatal cases of pertussis occur in infants <8 weeks of age, before initiation of the primary pertussis vaccine series. Women are recommended to receive tetanus, diphtheria, and acellular pertussis (Tdap) vaccine at the start of the third trimester of each pregnancy to optimize transplacental transfer of antibodies to the fetus. This recommendation was made by the Advisory Committee for Immunization Practices based on immunogenicity data, and no studies in the United States have yet evaluated the effectiveness of this strategy in reducing pertussis incidence in infants.

METHODS

 We evaluated a cohort of mothers with documented Tdap vaccination histories in the California Immunization Registry to determine whether infants whose mothers received Tdap vaccine at 27-36 weeks gestation had a lower risk of pertussis at <8 weeks of age than infants born to women who received Tdap vaccine within 14 days post partum.

RESULTS

 Tdap vaccination received at 27-36 weeks gestation was found to be 85% (95% confidence interval, 33%-98%) more effective than postpartum Tdap vaccination at preventing pertussis in infants <8 weeks of age . Vaccination at 27-36 weeks gestation was more effective at preventing pertussis in infant than vaccination during the second trimester.

CONCLUSIONS

 Tdap vaccination at 27-36 weeks gestation was 85% more effective than postpartum vaccination at preventing pertussis in infants <8 weeks of age. Efforts should be made by prenatal care providers to provide Tdap vaccine to pregnant women during routine prenatal visits at the earliest opportunity between 27 and 36 weeks gestation.

Fathers' Roles in the Care and Development of Their Children: The Role of Pediatricians

Fathers' involvement in and influence on the health and development of their children have increased in a myriad of ways in the past 10 years and have been widely studied. The role of pediatricians in working with fathers has correspondingly increased in importance. This report reviews new studies of the epidemiology of father involvement, including nonresidential as well as residential fathers. The effects of father involvement on child outcomes are discussed within each phase of a child's development. Particular emphasis is placed on (1) fathers' involvement across childhood ages and (2) the influence of fathers' physical and mental health on their children. Implications and advice for all child health providers to encourage and support father involvement are outlined.

Cost-Effectiveness of Pertussis Vaccination During Pregnancy in the United States

Vaccination against pertussis has reduced the disease burden dramatically, but the most severe cases and almost all fatalities occur in infants too young to be vaccinated. Recent epidemiologic evidence suggests that targeted vaccination of mothers during pregnancy can reduce pertussis incidence in their infants. To evaluate the cost-effectiveness of antepartum maternal vaccination in the United States, we created an age-stratified transmission model, incorporating empirical data on US contact patterns and explicitly modeling parent-infant exposure. Antepartum maternal vaccination incurs costs of $114,000 (95% prediction interval: 82,000, 183,000) per quality-adjusted life-year, in comparison with the strategy of no adult vaccination, and is cost-effective in the United States according to World Health Organization criteria. By contrast, vaccinating a second parent is not cost-effective, and vaccination of either parent postpartum is strongly dominated by antepartum maternal vaccination. Nonetheless, postpartum vaccination of mothers who were not vaccinated antepartum improves upon the current recommendation of untargeted adult vaccination. Additionally, the temporary direct protection of the infant due to maternal antibody transfer has efficacy for infants comparable to that conferred to toddlers by the full primary vaccination series. Efficient protection against pertussis for infants begins before birth. We highly recommend antepartum vaccination for as many US mothers as possible.

Cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women

OBJECTIVE

To evaluate the cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women using data from three recent influenza seasons in the United States.

DESIGN, SETTING, AND PARTICIPANTS

We developed a decision-analytic model following a cohort of 5.2 million pregnant women and their infants aged <6 months to evaluate the cost-effectiveness of vaccinating women against seasonal influenza during pregnancy from a societal perspective. The main outcome measures were quality-adjusted life-year (QALY) gained and cost-effectiveness ratios. Data sources included surveillance data, epidemiological studies, and published vaccine cost data. Sensitivity analyses were also performed. All costs and outcomes were discounted at 3% annually.

MAIN OUTCOME MEASURES

Total costs (direct and indirect), effects (QALY gains, averted case numbers), and incremental cost-effectiveness of seasonal inactivated influenza vaccination among pregnant women (cost per QALY gained).

RESULTS

Using a recent benchmark of 52.2% vaccination coverage among pregnant women, we studied a hypothetical cohort of 2,753,015 vaccinated pregnant women. With an estimated vaccine effectiveness of 73% among pregnant women and 63% among infants <6 months, QALY gains for each season were 305 (2010-2011), 123 (2011-2012), and 610 (2012-2013). Compared with no vaccination, seasonal influenza vaccination during pregnancy was cost-saving when using data from the 2010-2011 and 2012-2013 influenza seasons. The cost-effectiveness ratio was greater than $100,000/QALY with the 2011-2012 influenza season data, when CDC reported a low attack rate compared to other recent seasons.

CONCLUSIONS

Influenza vaccination for pregnant women can reduce morbidity from influenza in both pregnant women and their infants aged <6 months. Seasonal influenza vaccination during pregnancy is cost-saving during moderate to severe influenza seasons.

Dismantling the Taboo against Vaccines in Pregnancy

Vaccinating pregnant women in order to protect them, the fetus, and the child has become universal in no way at all. Prejudice in health professionals add to fears of women and their families. Both these feelings are not supported by even the smallest scientific data. Harmlessness for the mother and the child has been observed for seasonal, pandemic, or quadrivalent influenza, mono, combined polysaccharide or conjugated meningococcal or pneumococcal, tetanus toxoid, acellular pertussis, human papillomavirus, cholera, hepatitis A, Japanese encephalitis, rabies, anthrax, smallpox, yellow fever, mumps, measles and rubella combined, typhoid fever, inactivated or attenuated polio vaccines, and Bacillus Calmétte Guerin vaccines. Instead, the beneficial effects of influenza vaccine for the mother and the child as well as of pertussis vaccine for the child have been demonstrated. Obstetrician-gynecologists, general practitioners, and midwives must incorporate vaccination into their standard clinical care. Strong communication strategies effective at reducing parental vaccine hesitancy and approval of regulatory agencies for use of vaccines during pregnancy are needed. It must be clear that the lack of pre-licensure studies in pregnant women and, consequently, the lack of a statement about the use of the vaccine in pregnant women does not preclude its use in pregnancy.

Risk Factors for Pertussis Among Hispanic Infants: Metropolitan Portland, Oregon, 2010-2012

BACKGROUND

In 2012, Oregon observed its highest numbers of reported pertussis cases since 1953. The greatest morbidity occurred among infants <6 months of age, with higher rates among Hispanics than non-Hispanics. To explain this disparity, we analyzed pertussis surveillance data.

METHODS

An analysis was conducted among infants <6 months of age in the Portland metropolitan area during 2010-2012. Characteristics examined were ethnicity (Hispanic or non-Hispanic), household size (>4 or ≤4 persons), pertussis vaccination status (upto-date or not up-to-date for age), child care center attendance (yes or no), infant birth weight (<2500 or ≥2500 g) and maternal age (<20 or ≥20 years).

RESULTS

Eighty-two infants <6 months of age with pertussis were identified. Twenty-eight case-infants (34%) were Hispanic, and 54 (66%) were non-Hispanic. By ethnicity, infants with pertussis were similar in illness confirmation method, sex, age, hospitalization status, vaccination status, child care center attendance, infant birth weight and maternal age. Hispanic infants were more likely than non-Hispanic infants to live in households with >4 persons. Univariate analysis showed Hispanic infants had approximately 2.3 times the risk for pertussis, compared with non-Hispanic infants, and infants living in households >4 persons had approximately 2.4 times the risk for illness, compared with those in households with <4 persons; stratified risk ratios did not differ between Hispanic (2.4; confidence interval: 1.0-5.7]) and non-Hispanic infants (2.0; confidence interval: 1.2-3.5).

CONCLUSIONS

A household size of >4 persons is a potential risk factor for pertussis; the magnitude of this risk is similar for Hispanic and non-Hispanic infants.

Vaccine Timeliness: A Cost Analysis of the Potential Implications of Delayed Pertussis Vaccination in the US

BACKGROUND

Pertussis infection remains an important public health problem, particularly in infants. Despite high coverage, pertussis vaccination delays can leave infants at a vulnerable age with less protection than anticipated.

METHODS

Current diphtheria-tetanus-pertussis (DTaP) vaccination timeliness for the first 3 doses in the US was estimated using National Immunization Survey data. A Markov model estimated the potential impact on outcomes and costs of a hypothetical situation of vaccination at exactly 60, 120 and 180 days, compared with current timeliness. Incidence and unit cost data came from published sources. Age-specific incidence (for month of life) of pertussis and the associated probabilities of hospitalization and death for the US, during 2000-2007, were taken from a recently published US DTaP vaccination cost-effectiveness study. The cost analysis was conducted from the healthcare system's perspective over a 1-year time horizon. A regression analysis was conducted to explore the factors associated with vaccination delay.

RESULTS

Current DTaP vaccination was estimated to be delayed by 16, 27 and 44 days, for the first, second and third doses, respectively, relative to vaccination at exactly 60, 120 and 180 days. The model estimated that vaccination at exactly age 60, 120 and 180 days could prevent approximately 278 pertussis cases, 103 hospitalizations and 1 death in infants aged <1 year in the US, gaining approximately 38 quality-adjusted life years and saving approximately $1.03 million in healthcare costs.

CONCLUSIONS

Timely administration of infant pertussis vaccine doses could potentially reduce subsequent pertussis cases, hospitalizations, deaths and medical costs in infants aged <1 year in the US.

A Ten-Year Case-Control Study of Passive Smoke Exposure as a Risk Factor for Pertussis in Children

The authors conducted a matched case-control study of laboratory-confirmed pertussis cases, occurring from 1/1/1996 to 12/31/2005, in children up to 12 years of age who were members of a large managed care organization. Sixty-five laboratoryconfirmed cases of pertussis were identified. Using multivariable conditional logistic regression analysis, the authors did not detect a statistically significant association between pertussis and household passive exposure to cigarette smoking.

The pregnant healthcare worker: fact and fiction

PURPOSE OF REVIEW

A pregnant healthcare worker (HCW) may be at risk of occupational exposure to pathogens associated with increased maternal morbidity and mortality as well as perinatal complications. In this article, we review recent literature on infectious diseases commonly encountered in the healthcare setting and of highest concern for a pregnant HCW, focusing on prevention and management of exposures.

RECENT FINDINGS

Pregnancy does not seem to be an independent risk factor for occupationally acquired infectious diseases. Vaccination and standard precautions continue to be the most effective means of preventing transmission to HCWs. Pandemic 2009 influenza A (H1N1) is associated with increased risk of fetal death, highlighting the importance of influenza vaccination. A recent meta-analysis highlights the safety of influenza vaccination during pregnancy. New treatments for hepatitis C have not been studied in pregnancy but pose an important area for research and advancement. Cytomegalovirus immunoglobulin may play a role in postexposure prophylaxis but recent results are inconclusive.

SUMMARY

Primary prevention with vaccination and use of appropriate infection control precautions is imperative for prevention of occupationally acquired infectious diseases. Pregnant HCWs with occupational exposure to communicable diseases should be evaluated immediately for appropriate postexposure prophylaxis and followed for development of active infection.

Maternal Tdap vaccination: Coverage and acute safety outcomes in the vaccine safety datalink, 2007-2013

INTRODUCTION

Since October 2012, the combined tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccine (Tdap) has been recommended in the United States during every pregnancy.

METHODS

In this observational study from the Vaccine Safety Datalink, we describe receipt of Tdap during pregnancy among insured women with live births across seven health systems. Using a retrospective matched cohort, we evaluated risks for selected medically attended adverse events in pregnant women, occurring within 42 days of vaccination. Using a generalized estimating equation, we calculated adjusted incident rate ratios (AIRR).

RESULTS

Our vaccine coverage cohort included 438,487 live births between January 1, 2007 and November 15, 2013. Across the coverage cohort, 14% received Tdap during pregnancy. By 2013, Tdap was administered during pregnancy in 41.7% of live births, primarily in the 3rd trimester. Our vaccine safety cohort included 53,885 vaccinated and 109,253 matched unvaccinated pregnant women. There was no increased risk for a composite outcome of medically attended acute adverse events within 3 days of vaccination. Similarly, across the safety cohort, over a 42 day window, incident neurologic events, thrombotic events, and new onset proteinuria did not differ by maternal receipt of Tdap. Among women receiving Tdap at 20 weeks gestation or later, as compared to their matched controls, there was no increased risk for gestational diabetes or cardiac events while venous thromboembolic events and thrombocytopenia were diagnosed within 42 days of vaccination at slightly decreased rates.

CONCLUSION

Tdap coverage during pregnancy increased from 2007 through 2013, but was still below 50%. No acute maternal safety signals were detected in this large cohort.

Hospitalizations and deaths due to pertussis in children from 1996 to 2013

OBJECTIVES

To assess temporal trends of hospitalizations and deaths from pertussis in Brazilian children in the period of 1996-2013.

METHODS

This was a descriptive ecological study of temporal trends, based on the DATASUS database. The number of hospitalizations and deaths from pertussis in children up to 19 years of age from January 1996 to December 2013 was obtained. Descriptive statistics were applied for data analysis.

RESULTS

During the study period, a total of 19,047 hospital admissions from pertussis were recorded, of which 88.2% occurred in infants younger than 1 year. In the period 1996-2010, the mean annual number of admissions was 755, ranging from a maximum of 1179 in 2004 to a minimum of 400 in 2010. There was an increase of admissions in the last three consecutive years (2011, 2012, and 2013) with 1177, 2954 and 3589 hospitalizations, respectively. There were 498 deaths from pertussis throughout the study period, of which 96.8% occurred in children younger than one year. There was an increase in the number of deaths from pertussis in children in the years 2011, 2012, and 2013, with 40, 93, and 87 recorded deaths, respectively. The increase in hospitalizations and deaths from pertussis in children occurred in all regions of the country, with the highest increase observed in the Southeast, North and Northeast regions.

CONCLUSIONS

There was a substantial increase in hospitalizations and deaths from pertussis in children for three consecutive years (2011, 2012, and 2013) in all Brazilian regions. The most affected age group was that of children younger than one year.