Evaluation of several approaches to immunize parents of neonates against B. pertussis

Parental status and gender are associated with differences in Tdap vaccination rates among United States adults

Professional societies recommend all caregivers of neonates be vaccinated to Tdap to prevent neonatal pertussis. Limited data exist as to whether parents, including female parents (i.e. mothers) and male parents (i.e. fathers), are compliant with Tdap recommendations. We utilized individual-level self-reported Tdap vaccination information from the 2022 Behavioral Risk Factor Surveillance System (BFRSS) to assess the extent to which parental status was associated with Tdap vaccination status. Among reproductive age individuals (19-49 years old) with known parental status, only 28 % had Tdap vaccination: 38 % of female parents, 29 % of male parents, 30 % of female non-parents, 22 % of male non-parents. When compared to reproductive age female parents, the odds of Tdap vaccination were significantly lower for male parents (adjusted odds ratio (aOR) 0.65, 95 % Confidence interval (CI) [0.58-0.72]), female non-parents (aOR) 0.61, 95 % CI [0.56-0.66]), and male non-parents (aOR 0.45, 95 % CI (0.41-0.48) after adjusting for age, race, ethnicity, education, insurance, income, primary care provider status, and influenza vaccine status. When compared to male parents, in the adjusted models, male non-parents had lower odds of Tdap vaccination (aOR 0.69 (0.63-0.76)), while there was no difference in odds of Tdap vaccination for female non-parents (aOR 0.94 (0.86-1.04). Differences in Tdap vaccination by parental status and sex may be associated with parent-directed counseling by health care providers and routine Tdap vaccination during prenatal care for pregnant women. Efforts focused on education and vaccine administration for parents, particularly male parents, has potential to improve vaccination rates and increase neonatal protection.

Postpartum Interventions to Increase Maternal Vaccination Uptake: Is It Worth It?

BACKGROUND/OBJECTIVES

Vaccination of pregnant and postpartum women for pertussis, influenza and COVID-19 not only protects themselves but also offspring. Despite the benefits of this approach, vaccination uptake remains suboptimal in pregnancy. Where the opportunity to be vaccinated in pregnancy is missed, the offer of vaccination in the post-partum period may be an alternative strategy. The aim of this systematic review is to assess the impact of interventions to increase vaccination uptake in the postpartum period on vaccination uptake.

METHODS

A literature search was performed in MEDLINE, including interventional studies promoting vaccination uptake in postpartum women published between 2009 and 2024. The search was conducted according to PRISMA guidelines and registered with PROSPERO.

RESULTS

We finally included 16 studies in the review, and the primary outcome was vaccination uptake in the postpartum period. The most significant factors for increasing uptake were recommendation from healthcare providers, type of interventions used, and delivery of vaccines in the maternity wards or the community.

CONCLUSIONS

In conclusion, maternal vaccination rates in the postpartum period may increase with targeted education by healthcare professionals and positive reinforcement. The interventions described in these studies could be applied in the healthcare systems worldwide.

Characteristics of immunisation support programmes in Canada: a scoping review and environmental scan

OBJECTIVE

To identify, characterise and map the existing knowledge about programmes that provide immunisation support to Canadians and barriers and facilitators to their delivery.

DESIGN

Scoping review and environmental scan.

INTRODUCTION

Vaccine hesitancy may be associated with unmet support needs of individuals. Immunisation support programmes that provide multicomponent approaches can improve vaccine confidence and equitable access.

INCLUSION CRITERIA

Canadian programmes that focus on providing information about immunisation for the general public, but excluding articles targeting health professionals. The primary concept involves mapping the characteristics of programmes and our secondary concept examines barriers and facilitators to programme delivery.

METHODS

The Joanna Briggs Institute (JBI) methodology guided this review, reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. A search strategy was developed and translated for six databases in November 2021 (updated October 2022). Unpublished literature was identified through the Canadian Agency for Drugs and Technologies in Health Grey Matters checklist and other relevant sources. Stakeholders (n=124) from Canadian regional health authorities were also contacted by email for publicly accessible information. Two independent raters screened and extracted data from identified material. Results are presented in tabular form.

RESULTS

The search strategy and environmental scan resulted in 15 287 sources. A total of 161 full-text sources were reviewed after applying eligibility criteria, resulting in 50 articles. Programmes were delivered in multiple Canadian provinces, focusing on various vaccine types. All programmes aimed to increase vaccine uptake and were mostly provided in person. Multidisciplinary delivery teams based on collaborations among multiple entities were credited as a facilitator to programme delivery across settings. Limitations on programme resources, attitudes of programme staff and participants, and systems organisation were identified as barriers to delivery.

CONCLUSIONS

This review highlighted characteristics of immunisation support programmes across various settings and described multiple facilitators and barriers. These findings can inform future interventions that aim to support Canadians in making decisions about immunisation.

Knowledge and beliefs about vaccination in pregnant women before and during the COVID-19 pandemic

Introduction

Vaccine hesitancy threatens the health of populations and challenges Public Health professionals. Strategies to reduce it aim to improve people's risk perception about vaccine-preventable diseases, fill knowledge gaps about vaccines and increase trust in healthcare providers. During pregnancy, educational interventions can provide a proper knowledge about safety and efficacy of maternal and childhood vaccinations. Fighting hesitancy and clarifying doubts is fundamental during the COVID-19 pandemic, which may have affected people's knowledge and beliefs toward vaccination. This study aimed at assessing if the advent of the pandemic was associated with changes in pregnant women's knowledge and beliefs toward vaccination, and trust in healthcare services.

Methods

A repeated cross-sectional study was conducted through self-reported questionnaires in a Roman teaching hospital, where educational classes about vaccinations are routinely held as part of a birthing preparation course. Data were collected on a sample of pregnant women before and during the pandemic. Free-of-charge flu vaccinations were offered to all course participants and adherence to flu vaccination was assessed.

Results

The proportion of pregnant women reporting that vaccines have mild side effects and that are sufficiently tested increased from 78.6 to 92.0% (p = 0.001) and from 79.4 to 93.2% (p = 0.001), respectively. There was a reduction from 33.0 to 23.3% (p = 0.065) in the proportion of those declaring that healthcare workers (HCWs) give information only on the benefits and not on the risks of vaccines, and a reduction from 27.3 to 12.1% (p = 0.001) in those reporting that vaccines are an imposition and not a free choice of mothers. Trust in National Health Service (NHS) operators slightly decreased. Among participants, the monthly flu vaccination adherence ranged from 50.0% in November to 29.2% January for 2019–20 flu season, and from 56.3% in September to 14.5% in January for 2020–21 flu season, showing a higher vaccination acceptance in the earlier months of 2020-21 flu season.

Conclusions

The pandemic may have positively affected pregnant women's knowledge and opinions about vaccinations and trust in HCWs, despite a possible negative impact on their perceptions about NHS operators. This should inspire Public Health professionals to rethink their role as health communicators.

[Should French pregnant women be vaccinated against pertussis during pregnancy?]

Many countries with a high perinatal level have started a policy of vaccination of pregnant women against pertussis. To date, France has not chosen this policy. The objective was to review knowledge on pertussis mortality in infants. Compare the strategies available to protect the infant before his first vaccination, scheduled for two months of age. We proceeded to a litterature analysis, from January 1998 to 2021. Search by the following keywords used ; "Whooping cough, vaccination, pregnancy, strategy, cocooning", on the scientific basis of "Pubmed", as well as French and foreign vaccination recommendations. Currently 90% of whooping cough deaths are concerning infants under six months of age and this mortality represents 2% of mortality in the first year of life. Vaccination at birth is not effective. The cocooning strategy, which consists of vaccinating those around the child, is expensive and difficult to implement. A systematic vaccination policy for pregnant women is effective and reasonably expensive when compared to the cocooning strategy. In England, it was recently accompanied by a 78% reduction in confirmed cases of pertussis in infants under six months of age. In conclusion, compared to cocooning strategy, pertussis vaccination of pregnant women appears more effective and cost-effective, and this with each pregnancy.

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.

Factors associated with knowledges and attitudes about measles and rubella immunization in a non-health care occupational setting in Japan

INTRODUCTION

Elimination of measles and rubella has been achieved in several countries and some regions. After verified measles elimination, some countries have reported outbreaks among adults in occupational settings such as health care institution and school setting. Studies have reported that knowledge and attitude for measles and/or rubella are significantly associated with immunization uptake in adults, but few studies have been conducted in settings other than health care facilities and schools.

METHODS

We conducted a cross-sectional study among 134 office employees during a routine health checkup in June 17-20, 2014, to examine the association between willingness to receive immunization and knowledge and attitudes.

RESULTS

Approximately 75% had a protective level of antibody for measles (PA≥1:256) and rubella (HI ≥ 32 IU/mL). After adjustment for sex, age and immune status, the attitudes that immunization prevents measles (adjusted odds ratio [aOR] = 7.8, 95% confidence interval [95%CI]: 2.5-24.7) and prevents infection and transmission to others (aOR = 4.0, 95%CI: 1.4-11.4). Knowing that males are the vulnerable group for rubella infection (aOR = 5.8, 95%CI: 2.4-13.9), attitude that immunization prevents rubella infection (aOR = 7.9, 95%CI: 2.4-26.5), and prevents infection and transmit to others (aOR = 6.7, 95%CI: 2.2-20.1) were significantly associated with willingness to receive immunization after adjustment for sex, age, and immune status.

CONCLUSIONS

Studies have shown that physicians and other health care workers are important source of information for promotion of immunization. Thus, we recommend that physicians educate and promote immunization for measles and/or rubella to adults working in offices during routine health checks.

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.

Immunological and Clinical Benefits of Maternal Immunization Against Pertussis: A Systematic Review

Infants are vulnerable to pertussis infection particularly before initiation of pertussis vaccination. Maternal pertussis vaccination during pregnancy has been introduced in a number of countries in order to confer on young infants indirect protection from the disease through transplacental transfer of maternal antibodies. We reviewed the evidence on the immunogenicity and efficacy of maternal pertussis vaccination during pregnancy. A systematic search of PubMed/MEDLINE, EMBASE, Scopus, Cochrane Database of Systematic Reviews, ProQuest, and Science Direct was undertaken to identify studies published between January 1995 and December 2018. This review was not specific to any particular pertussis vaccine but included applicable data on available pertussis vaccines administered to pregnant women. The search identified 40 publications for inclusion in this review. Vaccination during pregnancy elicited robust maternal immune responses against all vaccine antigens and resulted in high placental transfer of pertussis antibodies to the infant that persisted well beyond delivery. Vaccination during the second or early third trimesters was considered ideal for antibody quantity and functionality. Although blunting of immune responses to some antigens in the primary immunization series was documented in neonates born to women vaccinated during pregnancy, there was no apparent adverse effect on vaccine efficacy. Multiple studies conducted in diverse settings have confirmed the effectiveness of maternal pertussis vaccination during pregnancy in preventing pertussis in infants prior to receipt of their first primary vaccine dose and beyond. These findings collectively underscore the value of maternal pertussis vaccination during pregnancy in protecting vulnerable infants too young to be vaccinated.Funding Sanofi Pasteur.Plain Language Summary Plain language summary available for this article.

Neonatal Pertussis, an Under-Recognized Health Burden and Rationale for Maternal Immunization: A Systematic Review of South and South-East Asian Countries

Pertussis is an under-recognized cause of neonatal morbidity and mortality. To review information on the epidemiology and disease burden of neonatal pertussis in South and Southeast Asian countries, a systematic literature review of three bibliographic databases was undertaken. Peer-reviewed original studies on neonatal pertussis epidemiology and burden published since 2000, with a geographical scope limited to South and Southeast Asian countries, were included. Data were systematically extracted based on parameters defined a priori. Our findings show that the burden of neonatal pertussis and its complications is substantial. An increase in the number of pertussis cases has been noted since early 2000, ranging from 61 to 92.9% in infants 0-3 months old. The most common symptoms an infant is likely to present with are cough with or without paroxysms, cyanosis, apnea, tachypnea, difficulty in breathing and leukocytosis. In addition, it can lead to hospitalization (length of stay: 5-7 days), complications (e.g., pneumonia, seizures) and mortality ranging from 5.6 to 14.7%. Other observations indicate that diagnosis is challenging because of non-specific clinical symptoms. Specifically, for obstetricians and gynecologists, the information available for making informed decisions on the prevention of neonatal pertussis is unreliable. Maternal immunization against pertussis during late stages of pregnancy has proven to be efficacious and well tolerated. A high burden of neonatal pertussis, as well as its complications, is observed in South and Southeast Asian countries. There is a need to intensify efforts to protect this vulnerable population with maternal vaccination.Funding: GlaxoSmithKline Biologicals SAPlain Language Summary: Plain language summary available for this article. Please see Fig. 1 and the following link: https://doi.org/10.6084/m9.figshare.7951187 .

Child-parent immunization survey: How well are national immunization recommendations accepted by the target groups?

•

Most of the time gynecologists had not recommended vaccinations to pregnant women.

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Only 3% of mothers were vaccinated against pertussis and influenza in pregnancy.

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Misconceptions led to non-compliance of pregnant women with recommended vaccinations.

Background

Pertussis disease rates are high in Switzerland, especially in infants and young infants. To protect newborns from this serious disease, EKIF, the Swiss National Immunization Technical Advisory Group, has recommended vaccination against pertussis during pregnancy (2nd or 3rd trimester) since 2013. Also, since 2009, EKIF has recommended vaccination against influenza during pregnancy.

We conducted this study to assess acceptance and implementation of these recently introduced recommendations.

Methods

We performed standardized interviews with parents of children born on or after 01.01.2013, hospitalized at the University of Basel Children’s Hospital, Switzerland, between January and June 2017. If participation was declined, partial consent was sought for four questions regarding age, education level, attitudes towards vaccinations in general and availability of vaccination records.

Results

In 193 of 398 eligible children the mother participated. Five (3%) of 172 mothers had received both pertussis and influenza vaccines during pregnancy, 15 (9%) only against pertussis and 12 (7%) only against influenza. Very few mothers had received vaccination recommendation during pregnancy: 17 (10%) for both pertussis and influenza and 15 (9%) each for pertussis and influenza only. Main reasons for refusal of vaccination despite recommendation were that they were not deemed useful (59% for influenza and 37% for pertussis) and safety concerns for the child (18% for influenza and 26% for pertussis).

Conclusions

Recommendation for and immunization rates against pertussis and influenza during pregnancy are low and need to be improved. As recommendations from health care personnel have been shown to have the most significant impact on immunization rates, we propose to focus on improving awareness and acceptance for immunization in pregnancy among health care personnel involved in the care of pregnant women.

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.

Reasons for use and non-use of the pertussis vaccine during pregnancy: an interview study

INTRODUCTION In New Zealand, pertussis vaccination is recommended and government-funded during every pregnancy to protect the infant after birth. However, uptake is low and needs to be increased. AIM To investigate enablers and barriers for uptake of the pertussis vaccination by pregnant women in New Zealand, and explore the acceptability of provision in pharmacies. METHODS Women with infants were recruited in selected pharmacies and interviewed using abrief structured interview. Transcripts were analysed using a framework approach. RESULTS Thirty-seven women aged 18-43 years provided data for analysis. Seventeen women reported receiving a pertussis vaccination during their pregnancy. Information from health professionals appeared important to encourage vaccination, but other sources of information (eg antenatal groups and media) were also cited. Non-vaccination arose from being unaware of the need for pertussis vaccination during pregnancy, concerns about safety, and misinformation. Participants supported pertussis vaccination in pharmacies to help access or increase the opportunity for health professionals to inform women. DISCUSSION The information received by participants affected their uptake of the pertussis vaccine during pregnancy. Education of the public and health professionals about the pertussis vaccine during pregnancy is necessary.

Protecting newborns from pertussis: The role of partner vaccination in the era of maternal immunization

OBJECTIVE(S)

While antenatal vaccination is the most effective strategy to reduce newborn pertussis infection and its associated morbidity and mortality, uptake has consistently been reported to be suboptimal. "Cocooning" or vaccination of the close contacts of newborns therefore remains an important strategy for protecting newborns when maternal vaccination has not occurred or with insufficient time for antibody transfer. This study assesses the uptake of pertussis vaccination by parents and close contacts of newborns providing insight into the vulnerability of newborns to pertussis upon discharge from hospital to their primary carers.

STUDY DESIGN

The study was conducted at three public and two private hospitals in Melbourne, Australia. A survey was administered to 689 women and/or their partners admitted on maternity wards of participating hospitals after delivery of a healthy newborn between August and December 2016. The main outcomes measured were reported vaccination rates and factors associated with uptake of pertussis vaccination. Kappa statistic and logistic regression were used to determine factors associated with vaccination.

RESULTS

70% of women and 66% of partners reported pertussis vaccination according to national recommendations. Significantly 22% of newborns were discharged to a household where neither parent reported vaccination. Compared to when maternal vaccination did occur, in families where it didn't there were low rates of vaccination of partners (83% vs 26%) and other carers, particularly carers usually resident overseas (76% vs 18.5%).

CONCLUSION(S)

While the majority of mothers and partners reported pertussis vaccination in accordance with recommended guidelines, concerningly nearly a quarter of newborns were discharged to a home where neither parent was vaccinated. When maternal vaccination did not occur, rates of vaccination of the other close contacts was poor. Educating women to encourage vaccination of partners and carers particularly those coming from overseas, prior to their arrival is an important consideration when maternal immunization does not occur. Cocooning remains an important approach to protect newborns of mothers vaccinated late or not vaccinated in pregnancy.

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.

[Cocooning strategy: Effectiveness of a pertussis vaccination program for parents in the maternity unit of a university hospital]

The aim of this study was to evaluate the impact on vaccination coverage of a protocol in which promotion and administration of pertussis vaccine in the maternity ward were proposed upon discharge from a French university hospital. Pertussis is a potentially fatal bacterial respiratory infection, especially in young infants. Since 2004 the High Council of Public Health has recommended vaccinating adults who may become parents. This recommendation is not widely applied in France. The study, organized as a professional practice evaluation (EPP) was conducted by a multidisciplinary team at Caen University Hospital. Thirty couples were included for each period. The primary endpoint was the rate of vaccination coverage for both parents at hospital discharge. Before the information campaign (first period, January 2012), immunization coverage of mothers and fathers was 20% and 13%, respectively. No couple had received a prescription for vaccines. During the second period (June 2013), vaccination coverage was 77% at hospital discharge for mothers and 57% for fathers. Parental immunization coverage against pertussis was multiplied by four to five during the study, which is very encouraging, and it is important to continue this campaign at the region and national levels.

Rediscovering Pertussis

Pertussis, caused by Bordetella (B.) pertussis, a Gram-negative bacterium, is a highly contagious airway infection. Especially in infants, pertussis remains a major health concern. Acute infection with B. pertussis can cause severe illness characterized by severe respiratory failure, pulmonary hypertension, leucocytosis, and death. Over the past years, rising incidence rates of intensive care treatment in young infants were described. Due to several virulence factors (pertussis toxin, tracheal cytotoxin, adenylate cyclase toxin, filamentous hemagglutinin, and lipooligosaccharide) that promote bacterial adhesion and invasion, B. pertussis creates a unique niche for colonization within the human respiratory tract. The resulting long-term infection is mainly caused by the ability of B. pertussis to interfere with the host's innate and adaptive immune system. Although pertussis is a vaccine-preventable disease, it has persisted in vaccinated populations. Epidemiological data reported a worldwide increase in pertussis incidence among children during the past years. Either acellular pertussis (aP) vaccines or whole-cell vaccines are worldwide used. Recent studies did not detect any differences according to pertussis incidence when comparing the different vaccines used. Most of the currently used aP vaccines protect against acute infections for a period of 6-8 years. The resurgence of pertussis may be due to the lack of herd immunity caused by missing booster immunizations among adolescents and adults, low vaccine coverages in some geographic areas, and genetic changes of different B. pertussis strains. Due to the rising incidence of pertussis, probable solution strategies are discussed. Cocooning strategies (vaccination of close contact persons) and immunizations during pregnancy appear to be an approach to reduce neonatal contagiousness. During the past years, studies focused on the pathway of the immune modulation done by B. pertussis to provide a basis for the identification of new therapeutic targets to enhance the host's immune response and to probably modulate certain virulence factors.

[Is it ethically acceptable to invite a pregnant woman to enroll in a clinical trial with Tdap if it could entail not being vaccinated with Tdap before delivery?]

Pertussis incidence has increased in recent years, especially among infants aged <2months. A number of Spanish regions have started a vaccination program with Tdap vaccine to all pregnant women in the third trimester of pregnancy. An observational study has shown that this strategy reduces the number of cases of pertussis by 90% in infants aged <2months. Mathematical models showed that a cocooning strategy (i.e. vaccination of the mother at immediate postpartum, and other adults and adolescents who have close contact with the newborn and caregivers) will reduce the incidence of pertussis by 70% in infants aged <2months. It is intended to conduct a clinical trial in which 340 pregnant women will receive Tdap vaccine, whereas another 340 pregnant woman will be vaccinated soon after delivery. Vaccination with Tdap will be offered to all partners and caregivers of the newborn. After assessing both the ethical and scientific reasons supporting the trial, it is concluded that it is ethically and legally acceptable to invite pregnant women living in communities where Tdap vaccination has been implemented to participate in the trial.

Knowledge and Acceptability about Adult Pertussis Immunization in Korean Women of Childbearing Age

PURPOSE

The adult tetanus, reduced diphtheria, and acellular pertussis (Tdap) vaccine has been introduced in order to provide individual protection and reduce the risk of transmitting pertussis to infants. We assessed the knowledge and acceptability of the Tdap vaccine around pregnancy.

MATERIALS AND METHODS

This study was a cross-sectional survey of women of childbearing age (20-45 years) who visited obstetrics and gynecologic units of primary, secondary, or tertiary hospitals. They were asked to fill in a questionnaire assessing their knowledge, attitudes, and acceptability of Tdap.

RESULTS

The questionnaire was completed by 308 women; 293 (95.1%) had not received information from doctors about Tdap, and 250 (81.2%) did not know about the need for vaccination. A significantly important factor related to subjects' intention to be vaccinated, identified by stepwise multiple logistic regression, was the knowledge (OR 13.5, CI 3.92-46.33) that adult Tdap is effective in preventing pertussis for infants aged 0-6 months. Additionally, 276 (89.6%) considered the recommendation of obstetric doctors as the most influencing factor about Tdap vaccination.

CONCLUSION

In Korea, most women of childbearing age seem to be neither recommended nor adequately informed about the vaccination, although our population was not a nationwide representative sample. Information given by healthcare workers may be critical for improving awareness and preventing pertussis.

Management and prevention of pertussis infection in neonates

Despite the fact that universal immunization against pertussis led to a dramatic decrease in the incidence and mortality in high-income countries, it has left a window of vulnerability for newborns. Although specific guidelines concerning management of neonatal whooping cough have not yet been developed, the present review summarizes the main available recommendations on diagnostic work-up and treatment of neonatal pertussis. Additionally, new prevention strategies are explored, including the use of an additional booster dose of vaccine to adolescents and adults, vaccination of healthcare workers, immunization of household contacts and caregivers (cocooning strategy), vaccination of pregnant women and, finally, neonatal immunization with novel vaccines. These strategies are analyzed and discussed in terms of efficacy, safety and cost-effectiveness.

Pertussis

Pertussis continues to be an important public-health issue. The high immunization coverage rates achieved, mainly in industrialized countries, have certainly decreased the spread of the pathogen. However, as immunity wanes, adolescents and adults play an important role in the dynamics of the infection. The surveillance system has several limitations and the underestimation of pertussis in adolescents, young adults and adults is mainly related to the atypical clinical characteristics of cases and the lack of lab confirmation. The real epidemiological impact of pertussis is not always perceived. The unavailability of comprehensive data should not hamper the adoption of active prophylactic measures designed to avoid the impact of waning immunity against pertussis. Different immunization strategies have been suggested and/or already adopted such as immunization of newborns, pre-school and school children, adolescents, adults, healthcare workers, childcare workers, pregnant women, cocoon strategy. Prevention of pertussis requires an integrated approach and the adoption of different immunization strategies, with the objective of achieving and maintaining high coverage rates.

Neonatal pertussis, cocooning and maternal immunization

The rising incidence of whooping cough, a highly contagious infection caused by Bordetella pertussis, is particularly significant for young infants who have the highest risk for morbidity and mortality. The pertussis resurgence has led to a shift in primary prevention relying on childhood vaccination to a cocooning strategy, that is, vaccination of close contacts of newborn infants (new mothers, fathers, grandparents, siblings, caretakers, etc.), thereby reducing pertussis exposure. Immunization of women during pregnancy rather than during the immediate postpartum period (the initial cocooning recommendation) appears to be a better approach by directly providing protection through transplacental transfer of maternal vaccine-induced antibodies. This article describes neonatal pertussis, cocooning as a means of reducing neonatal exposure to pertussis and maternal immunization as a means of protecting young infants against pertussis infection.

Protecting newborns from pertussis - the challenge of complete cocooning

BACKGROUND

An increase of pertussis cases, especially in young infants and adolescents, has been noted in various countries. Whooping cough is most serious in neonates and young infants in whom it may cause serious complications such as cyanosis, apnoea, pneumonia, encephalopathy and death. To protect newborns and infants too young to be fully immunized, immunization of close contact persons has been proposed ("cocoon strategy") and implemented in several countries, including Switzerland in 2011. The goal of this study was to assess knowledge about pertussis among parents of newborns and acceptance, practicability and implementation of the recently recommended pertussis cocoon strategy in Switzerland.

METHODS

We performed a cross sectional survey among all parents of newborns born between May and September 2012 and 2013 in Basel city and country. Regional statistical offices provided family addresses after approval by the ethical and data protection committees. A standardized questionnaire with detailed instructions was sent to all eligible families. For statistical analyses, independent proportions were compared by Pearson's chi-squared test.

RESULTS

Of 3546 eligible parents, 884 (25%) participated. All three questions exploring pertussis knowledge were answered correctly by 37% of parents; 25% gave two correct answers, 22% gave one correct answer and in the remaining 16% no answer was correct. Pertussis immunization as part of cocooning was recommended to 20% and 37% of mothers and 14% and 32% of fathers in the 2012 and 2013 study cohorts, respectively. Principal advisors for cocooning were pediatricians (66%) followed by gynecologists/obstetricians (12%) and general practitioners (5%). When recommended, 64% of mothers and 59% of fathers accepted pertussis immunization. The majority of vaccinations were administered in the perinatal period and within 2 months of the child's birth. However, cocooning remained incomplete in 93% of families and in most families <50% of close contacts received pertussis vaccination.

CONCLUSIONS

Implementation of cocooning for protecting newborns from pertussis is challenging and usually remains incomplete. Pertussis immunization rates among close contacts of newborns need to be improved. Ideally, all healthcare providers involved in family planning, pregnancy and child birth should recommend cocooning. Pertussis immunization of pregnant women is an additional measure for optimal protection of newborns and should be promoted.