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Neonatal pertussis can potentially cause severe complications and even death. Mothers have been most frequently identified as the source of neonatal pertussis. Approximately a dozen countries have implemented pertussis vaccination programs for pregnant women to protect neonates; however, in Japan, this has not been implemented. The aim of this questionnaire-based study was to ascertain the willingness of women to be vaccinated during pregnancy and the factors associated with willingness. The subjects were 977 pregnant women who visited either of the two selected hospitals for maternity health checks. Most of the women were in their first pregnancy (96%), and approximately half of them considered a physician to be the most reliable source of information about vaccination (481/977, 49%). "Willingness to receive pertussis vaccination" was significantly associated with the factors "no fear of receiving vaccination" (odds ratio [OR] = 3.10, 95% confidence interval [CI]: 2.21-4.34), "necessary to prevent pertussis" (OR = 8.70, 95% CI: 6.17-12.28), "effective in pregnancy" (OR = 5.46, 95% CI: 3.94-7.56), and "no concern about the side effects after vaccination" (OR = 3.03, 95% CI: 1.66-5.55). Pregnant women are likely to consider vaccination if they have a good understanding of the disease and its outcomes. Physicians are well positioned to improve knowledge and attitudes toward pertussis vaccination during pregnancy.

Background Hypotonic-hyporesponsive episode (HHE) after whole cell pertussis vaccination is a known adverse event. Less is known about the risk of HHE after administration of acellular pertussis vaccines. Methods Using parental interviews, this study actively surveyed for HHE among infants after doses 1 and 2 of acellular pertussis vaccine. Results We interviewed the parents of 52,531 infants. HHE was reported at a rate of 22.8 per 100,000 doses (95% CI: 11.8-39.9) of acellular pertussis vaccine, approximately 45 episodes per 100,000 children. Conclusions These rates are lower than HHE rates reported after whole cell pertussis vaccines and within the range of HHE rates reported in other studies of acellular pertussis vaccines.

This cross-sectional study assessed prenatal pertussis vaccination acceptance in Taiwan. A sample of pregnant women from five private clinics in Taiwan was recruited. Demographics, experience of prenatal vaccinations, key considerations, knowledge, and attitude about pertussis and its vaccination were measured. Among 505 participants, the vaccination rate, including planned vaccination, was 29.7%. Factors associated with acceptance included clinic location, primary caregiver of the newborn, newborns with siblings, previous influenza vaccination history, knowledge and attitude toward pertussis and its vaccination. Public health agencies should provide free vaccinations, clarify misinformation, and publicize prevention information, to improve prenatal pertussis vaccination acceptance.

Objective: to investigate pertussis vaccination rates during pregnancy and the routine recommendation rates by maternity healthcare professionals (HCPs), including influencing factors, in Korea. Materials and methods: Two different questionnaires were developed and conducted anonymously for pregnant or postpartum women and maternity HCPs in 30 multi-centers. Maternal pertussis vaccination rates and maternity HCPs’ recommendation rates were analyzed. Independent influencing factors were analyzed using multivariate logistic regression analysis, respectively. Results: The rate of pertussis vaccination during pregnancy among 466 women was 67%. Among 164 multiparous women, 35.5% received pertussis vaccinations during every pregnancy. However, 27.9% among all pregnant women did not receive information about pertussis and vaccination. The independent influencing factors for maternal pertussis vaccination, given as the tetanus, diphtheria and acellular pertussis (Tdap), were “getting informed” (OR 18.597, 95% CI 11.206–30.861), “informed by OBGYN doctors” (OR 4.426, 95% CI 2.144–9.267), and “metropolitan residence” (OR 3.048, 95% CI 1.419–6.548). Among a total of 373 maternity HCPs, 210 (56.3%) routinely recommended pertussis vaccination, but 21.7% of the total maternity HCP participants did not know the maternal Tdap guideline. The independent factors affecting routine recommendation were the awareness of guideline (OR 9.771, 95% CI 5.227–18.265, p

Background: The intention of Chinese people older than age 5 to accept the pertussis vaccination is unknown, which is important for the future design of an effective pertussis vaccination program in China. Method: We conducted a cross-sectional survey among people older than age 5 in China. A 24-item questionnaire was used to explore the determinants of intention to accept a pertussis vaccination, and for children and adolescents (≦15 years old), their guardian was required to help answer the questionnaire on their behalf. Univariate and multivariate logistic regression was used to analyze the influencing factors of intention. Results: A total of 3,041 individuals participated in our survey and 3025 completed the questionnaire, among which 1938 (64.07%) reported a positive intention to be vaccinated. A multiple logistic regression analysis revealed that the main positive factors for the intention to accept pertussis vaccination were younger age (Odd ratio [OR] 0.838, P

Aims The Centre for Health Protection of Hong Kong has issued a recommendation on pertussis vaccination during pregnancy to protect infants against pertussis. This study aimed to explore the knowledge, perceptions, and attitudes toward pertussis vaccination during pregnancy among pregnant women in Hong Kong. Methods This was a cross-sectional study conducted over a 6-week period from August 17 to September 30 2019 among pregnant women in an obstetrics department in a regional public hospital in Hong Kong. Information on participants' demographics, medical, and immunization history, their knowledge, perception and attitudes, toward pertussis vaccination during pregnancy were gathered. Point-biserial correlation coefficients were used to determine correlation between variables. Results Only 112 (24.6%) women knew that pertussis vaccination can be given during pregnancy and 53 (11.6%) recognized that antenatal pertussis vaccination should be given in each pregnancy. Despite poor knowledge on the vaccination, over 80% of women showed an intention to receive pertussis vaccination during pregnancy. Fifty-two (71.3%) women expressed that recommendations by healthcare professionals may alter their decision on vaccination uptake. The score in the knowledge section and the perception to the vaccination positively correlated with the intention to be vaccinated. Those who were given advice by healthcare professionals were more likely to indicate an intention to receive the vaccination. Conclusion Pregnant women in Hong Kong are likely to accept antenatal pertussis vaccination despite the poor knowledge on vaccination in pregnancy and antenatal pertussis vaccination. Recommendations by healthcare professionals are a key factor affecting women's decision on vaccination uptake.

Introduction: The Accelerated Development of Vaccine benefit-risk Collaboration in Europe (ADVANCE) public-private collaboration, aimed to develop and test a system for rapid benefit-risk monitoring of vaccines using healthcare databases in Europe. The objective of this proof-of-concept (POC) study was to test the feasibility of the ADVANCE system to generate incidence rates (IRs) per 1000 person-years and incidence rate ratios (IRRs) for risks associated with whole cell- (wP) and acellular- (aP) pertussis vaccines, occurring in event-specific risk windows in children prior to their pre-school-entry booster. Methods: The study population comprised almost 5.1 million children aged 1 month to

The Global Pertussis Initiative is an expert scientific forum that publishes consensus recommendations concerning pertussis for many regions of the world. Here, we give recommendations for the primary vaccination of infants in those countries where whole-cell pertussis (wP)- and acellular pertussis (aP)-containing combination vaccines are used in parallel. A selective literature review was performed concerning the influence on safety, immunogenicity, and effectiveness of mixing wP- and aP-containing vaccines for primary immunization of infants. In addition, local data were collected from various countries and the results discussed in a face-to-face meeting. Very few data addressing issues of mixing combination vaccines were identified, and no data were available concerning the effectiveness or duration of protection. It was also found that pharmacovigilance data are scarce or lacking in those countries where they would be needed the most. We then identified frequent problems occurring in low- and middle-income countries (LMICs) where both vaccine types are used. Relying on local knowledge, we give practical recommendations for a variety of situations in different settings. Specific needs for additional data addressing these issues were also identified. International bodies, such as the World Health Organization (WHO), as well as vaccine producers should try to find ways to highlight the problems of mixing wP- and aP-containing combination vaccines with robust data. Countries are urged to improve on their pharmacovigilance for vaccines. For practicing physicians, our recommendations offer guidance when wP- and aP-containing vaccines are used in parallel during primary immunization., Instituto de Biotecnologia y Biologia Molecular

Background Prenatal pertussis vaccination was introduced in 2012 in England and is primarily delivered through general practice. Since 2017 some maternity services are commissioned to offer it too. We aimed to describe the maternity service delivery of prenatal pertussis vaccination and its impact on vaccine uptake. Methods We described the proportion of maternity services in England commissioned to offer pertussis vaccination to pregnant women in 2017/18 and the proportion of women vaccinated in this setting using a self-administered survey of NHS commissioners. We categorised clinical commissioning groups (CCGs) in England into “implementing” and “non-implementing” pertussis vaccination in maternity services. We identified CCGs where vaccination data was reliably transferred from maternity services to primary care records (source of routine data on vaccine uptake) and among those compared changes in vaccine uptake in implementing vs non-implementing CCGs between March 2016 (before implementation) and March 2018 (after). Findings Of 141 maternity service units in England, 61% delivered prenatal pertussis vaccine in 2017/18. Of those 57.0% of maternity services immunized less than 10% of pregnant women and only 7.1% of maternity services immunized more than 40% of pregnant women. Between March 2016 and March 2018, coverage increased by 19.6% among non-implementing CCGs compared with 17.8% among all implementing CCGs (difference −2.2, p = 0.48) and 28.2% among implementing CCGs with reliable methods of data transfer (difference 8.6, p = 0.04). This difference translated to a difference of 1.6 percentage points in absolute terms. Interpretation Delivering pertussis vaccine through maternity services has a moderate but important impact on vaccine uptake. There is a need to improve data transfer on vaccines administered in maternity service units to primary care. Maternity services should offer the vaccine to improve coverage and thus optimise protection for young infants. Barriers to effective programme implementation should be investigated and addressed.

Background In October 2012, a maternal pertussis vaccination program was introduced in England for women between 28 and 32 weeks of pregnancy. In April 2016, the recommended optimal window was extended to 20–32 weeks to improve vaccine coverage and protect preterm infants. This study assesses the impact of offering maternal pertussis vaccination earlier in pregnancy on hospitalized infant pertussis cases. Methods Hospitalized pertussis cases ≤60 days old in England were extracted from Hospital Episode Statistics pre- and post-policy change. Data were linked to laboratory-confirmed cases, and clinical records were reviewed where cases were not matched. Maternal vaccine status of identified cases was established. Median hospital duration was calculated, and a competing risk survival analysis was undertaken to assess multiple factors. Results A total of 201 cases were included in the analysis. Of the 151 cases with reported gestational age, the number of hospitalizations among full-term infants was 60 cases pre-policy and 62 cases post-policy, respectively, while preterm cases declined from 20 to 9 (P = .06). Length of hospital stay did not differ significantly after the policy change. Significantly longer hospital stays were seen in cases aged 0–4 weeks (median of 3 more days than infants aged 5–8 weeks), premature infants (median of 4 more days than term infants), and cases with coinfections (median of 1 more day than those without coinfection). Conclusions The number of preterm infants hospitalized with pertussis in England was halved after the policy change and preterm infants were no longer overrepresented among hospitalized cases., This study evaluates the impact of offering pertussis vaccination earlier in pregnancy in the second trimester on hospitalized infant pertussis cases in England. We found a decline in hospitalizations in preterm infants from 20 (18.5%) to 9 (9.7%) (P = .06).

Objective: As the current recommendation of administering Tdap (tetanus-diphtheria-acellular pertussis) to all pregnant women has not been widely implemented in the United Arab Emirates (UAE), we aimed to ascertain the prevalence of pertussis seronegativity during pregnancy. Methods: IgG antibodies against Bordetella pertussis toxin (PT) were measured in 213 women attending the antenatal clinic at Oasis hospital, Al Ain, UAE. Results were compared by maternal age, nationality and gestational age with the Kruskal–Wallis test for IgG-PT levels and the Chi-squared test for serology status. Results: The mean age ± SD of the participants was 30.4 ± 5.6 years, mean gestational age ± SD of 25.5 ± 3.3 weeks. Serum concentration of IgG-PT

Background A suboptimal maternal vaccination coverage in 2017–18 has been reported in Italy. The study aims were to (i) assess changes in maternal influenza and tetanus, diphtheria and acellular pertussis vaccination coverage during 2018–19 influenza season compared to the previous season (ii) estimate influenza vaccine coverage among maternal care providers (MCPs) and (iii) explore the characteristics of vaccine delivery to pregnant women. Methods We conducted a cross-sectional survey among pregnant women and MCPs about influenza and pertussis immunization during pregnancy. We also collected information regarding prenatal care characteristics and vaccine delivery among four centers in Italy. Results We recruited 483 pregnant women and 452 MCPs. The influenza and pertussis vaccine uptake among pregnant women for the season 2018–19 was 14.9% and 60.9%, respectively. MCPs’ influenza vaccine uptake was 33.6%. Knowing that the flu vaccine was safe for mothers and their infants and being vaccinated in the previous influenza season were associated with higher vaccine uptake. Regarding pertussis, being a housewife was associated to lower vaccine uptake, while knowing the vaccine is effective and safe for mothers and newborns were associated with higher pertussis vaccine uptake. The single most important factor associated to higher coverage of both influenza and pertussis vaccines was receiving a health-care provider’s vaccine advice. Most pregnant women (69.4%) stated that they preferred to be vaccinated in their same prenatal care setting. Conclusions Receiving a health-care provider’s vaccine advice and the availability of vaccines during prenatal care visits might improve vaccination coverage among pregnant women.

BackgroundInterventions to mitigate coronavirus disease 19 (COVID-19) pandemic may impact other respiratory diseases such as pertussis. We aimed to study the course of pertussis in France over an 8-year period and its association with COVID-19 mitigation strategies, using multiple nationwide data sources.MethodsWe analyzed the number of French pertussis cases between 2013 and 2020, using the PCR test results from nationwide outpatient laboratories (Source 1) and the pediatric network of 41 hospitals (Source 2), and using the reports of an office-based pediatric national network (Source 3). We conducted a quasi-experimental interrupted time-series analysis, relying on negative binomial regression models. The models accounted for seasonality, long-term cycles, and secular trend, and included a binary variable for the first national lockdown (ordered on March 16, 2021).ResultsWe identified 19,039 cases of pertussis from the three data sources during the study period. There was a significant decrease of pertussis cases following the implementation of mitigation measures, with adjusted incidence rate ratios of 0.102 (95% CI 0.040-0.256) and 0.216 (95% CI 0.071-0.656) for Source 1 and Source 2, respectively. The association was confirmed in Source 3 (median of 1 [IQR 0-2] vs. 0 [IQR 0-0] pertussis cases per month before and after lockdown, respectively, p=0.0048).ConclusionThe drastic reduction of outpatient and hospitalized cases of pertussis strongly suggests an impact of COVID-19 mitigation measures and their consequences on pertussis epidemiology. Pertussis vaccination recommendations should be carefully followed, and disease monitoring should be continued to detect any resurgence after relaxation of mitigation measures.FundingThere was no specific funding for the study.

Background: Bordetella pertussis, a highly contagious respiratory. Notably, the resurgence of pertussis has recently been associated with the lacking production of vaccine virulence factors. This study aimed to screen pertactin (Prn) and filamentous hemagglutinin (Fha) production in Iran with 50 years' whole cell vaccine (WCV) immunization program. Methods: Overall, 130 B. pertussis isolates collected from Pertussis Reference Laboratory of Iran during 2005-2018. Real-time PCR was performed by targeting IS481, ptxP, IS1001 and IS1002 for species confirmation of B. pertussis. Western-blot was used to evaluate the expression of virulence factors (pertactin and filamentous hemagglutinin). Results: All tested B. pertussis isolates expressed Prn and all except two isolates expressed Fha. We have sequenced genomes of these strains and identified differences compared with genome reference B. pertussis Tohama I. Conclusion: Many countries reporting Prn and Fha-deficiency due to acellular vaccine (ACV) pressure. Our results demonstrate in a country with WCV history, Fha-deficient isolates may rise independently. However, Prn-deficient isolates are more under the ACV pressure in B. pertussis isolates. Continues surveillance will provide a better understanding of the effect of WCV on the evolution of the pathogen deficiency.

Previous studies from low-resource countries have highlighted concerns surrounding non-specific effects of whole-cell pertussis vaccination, particularly in females. We sought to examine the effects of sex and birth weight on health services utilization following first exposure to whole-cell pertussis vaccine. Using a self-controlled case series design and by calculating relative incidence ratios (RIRs), we compared the relative incidence of emergency department visits and/or hospital admissions between sexes and between birth weight quintiles. Females had a higher relative incidence of events following vaccination compared to males (RIR = 1.13, 95% CI: 0.99, 1.30), which persisted after adjustment for birth weight (RIR = 1.12, 95% CI: 0.97, 1.28). We also observed a trend of increasing relative incidence of events over decreasing quintiles of birth weight; infants in the lowest quintile had a 26% higher relative event rate compared to the highest quintile, which was robust to adjustment for sex (Unadjusted RIR = 1.26, 95% CI: 1.01, 1.56; Adjusted RIR = 1.23, 95% CI: 0.99, 1.53). The risk of all-cause health services utilization immediately following vaccination, was elevated in female infants and infants having lower birth weight. Further study is warranted to determine if vaccine dosing should take infant weight into account.

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

ZusammenfassungKeuchhusten wird bei Patienten nach Erfahrung des Autors häufig übersehen, da viele Ärzte anscheinend nicht mehr mit dem Auftreten der Erkrankung rechnen. Die Inzidenz des Keuchhustens ist jedoch ansteigend, und selbst eine erfolgte Impfung oder eine früher durchgemachte Erkrankung sind keine Garantie für eine lang andauernde Schutzwirkung. Ziel dieses Artikels ist daher, einen Überblick über die Erkrankung, ihre Diagnostik und Therapiemöglichkeiten zu geben, sowie auf mögliche Gründe hinzuweisen, warum der Keuchhusten oft übersehen wird. Anhand mehrerer Fälle aus meiner Praxis wird schließlich die homöopathische Behandlung des Keuchhustens näher betrachtet.

Introduction: The objective was to estimate the effectiveness of maternal pertussis vaccination in protecting infants aged < 2 months. Methods: We performed a case-control study. Laboratory-confirmed cases aged < 8 weeks at disease onset were identified and 2-4 matched-controls born within +/- 15 days of the case were included. Information was obtained from healthcare providers and maternal interviews. Odds ratios (OR) were calculated using multivariable conditional logistic regression. Vaccine effectiveness (VE) was estimated as (1 - OR) x 100%. Results: 47 cases and 124 controls were studied. The mean age (in days) (39.8 +/- 12.7 vs. 40.8 +/- 13.2), weeks of gestation (38.8 vs. 39.1, p = 0.43) and mean birth weight (3.309 vs. 3.253 kg, p = 0.55) were comparable between cases and controls. Mothers of cases were less frequently vaccinated in the third trimester (59.6% vs. 83.9%, p < 0.001). The VE of maternal vaccination in pregnancy was 88.0% (95%CI 53.8%-96.5%), and was slightly higher in those vaccinated before the 32nd week of gestation (88.5% vs 87.8%). Conclusion: Pertussis vaccination in pregnancy is very effective in reducing pertussis in children aged < 2 months. Vaccination before and after the 32nd week of pregnancy are equally effective in reducing the risk of pertussis. (c) 2021 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Altres ajuts: acords transformatius de la UAB Aims and Objectives: To identify how pregnant women perceive pertussis and influenza and the factors that influence their decision to be vaccinated. Background: Suffering from influenza during pregnancy increases complications in the pregnant woman, foetus and newborn. Pertussis in children under six months of age causes severe complications. Maternal vaccination against influenza and pertussis is effective and safe. However, vaccination rates are insufficient. Design: We conducted a qualitative descriptive study, using semi-structured interviews. This research adheres to the COREQ guidelines and checklist. Methods: We carried out 18 semi-structured face-to-face interviews with pregnant women, using intentional sampling and thematic analysis. Results: We identified an overarching theme, 'factors that influenced participants' decision to be vaccinated or not', which was composed of four subthemes that were in turn made up of 12 categories. The factors that influenced participants' decision to be vaccinated against influenza and pertussis were related to their knowledge of and their perception of risk for these diseases. Participants perceived the risk of pertussis to be greater, and they focused their concern on the newborn. The recommendations and convictions of nurse-midwives were the most important factors encouraging vaccination. Participants trusted their nurse-midwives and most reported that they would have been vaccinated if their midwife had recommended it. Other factors were linked to lack of information, fear and concerns about economic interests. Conclusions: The convictions and actions of the nurse-midwife in recommending vaccination to pregnant women are decisive. Strategies to improve vaccination rates should be directed to helping health professionals understand how their practice affects the final decision of pregnant women. Relevance to clinical practice: Understanding the factors that limit vaccination rates among pregnant women provides valuable information to nurse-midwives that can help to improve vaccination strategies and practices. Increased maternal vaccination rates would reduce morbidity and mortality among pregnant women and newborns.

The Accelerated Development of VAccine benefit-risk Collaboration in Europe (ADVANCE), a public-private consortium, implemented and tested a distributed network system for the generation of evidence on the benefits-risks of marketed vaccines in Europe. We tested the system by estimating the incidence rate (IR) of pertussis and pertussis-related complications in children vaccinated with acellular (aP) and whole-cell (wP) pertussis vaccine. Data from seven electronic databases from four countries (Denmark: AUH and SSI, Spain: SIDIAP and BIFAP, UK: THIN and RCGP RSC and Italy: Pedianet) were included in a retrospective cohort analysis. Exposure was defined as any pertussis vaccination (aP or wP). The follow-up time started 14 days after the first dose. Children who had received any pertussis vaccine from January 1990 to December 2015 were included (those who switched type, or had unknown type were excluded). The outcomes of interest were confirmed or suspected pertussis and pertussis-related pneumonia and generalised convulsions within one month of pertussis diagnosis and death within three months of pertussis diagnosis. The cohort comprised 2,886,367 children ≤5 years of age. Data on wP and aP vaccination were available in three and seven databases, respectively. The IRs (per 100,000 person-years) for pertussis varied largely and ranged between 0.15 (95% CI: 0.12; 0.19) and 1.15 (95% CI: 1.07; 1.23), and the trends over time was consistent with those observed from national surveillance databases for confirmed pertussis. The pertussis IRs decreased as the number of wP and aP vaccine doses increased. Pertussis-related complications were rare (89 pneumonia, 7 generalised convulsions and no deaths) and their relative risk (vs. non-pertussis) could not be reliably estimated. The study demonstrated the feasibility of the ADVANCE system to estimate the change in pertussis IRs following pertussis vaccination. Larger sample sizes would provide additional power to compare the risk for complications between children with and without pertussis. The feasibility of vaccine-type specific effectiveness studies may be considered in the future.

Background: Whole-cell pertussis (wP) vaccine administration is still advocated for children under 7 years of age in Iran. However, there is no recommendation for the administration of a dose of tetanus, diphtheria, and acellular pertussis (Tdap) vaccine to childbearing age/pregnant women in the Iranian vaccination program and it has increased the risk of infection through waning immunity during women’s childbearing age life. The study aimed to assess the levels of anti- Bordetella pertussis antibodies in childbearing age women of different ages in Iran. Methods: A cross-sectional study was conducted on a total number of 360 childbearing age women divided into six age groups, with 5-year intervals from 15 to 45 years old, in 2018–2019. Then, the levels of immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) antibodies against B. pertussis were evaluated using enzyme-linked immunosorbent assay (ELISA). The IBM SPSS Statistics software (version 16.0) (SPSS Inc., Chicago, IL, USA) was used for data analysis. Results: The mean age of the participants was 30.01 ± 8.35 years (range 14–45 years). All the cases were IgM negative, but two IgA-positive individuals (in the age groups of 14–19 and 30–34 years) were reported. Overall, 239 (66.4%) cases were IgG positive. The mean age of IgG-positive cases was 30.37 ± 8.37 years. The IgG-positive cases were mostly in the age groups of 30–34 and 35–39 years [43 (71.1%)]. The odds of IgG positivity were 1.97. The highest odds of IgG positivity were seen in 30–34 and 35–39 years groups (2.52) and the lowest odds were seen in the 20–24 and 25–29 years groups (1.60). Using the Jonckheere–Terpstra test, the increasing trend of IgG changes in different age groups was not statistically significant (Tπ=5.78, p = 0.09). Conclusion: The infants of women of childbearing age might be prone to pertussis in countries using the wP vaccination schedule. It is suggested to administer a dose of Tdap to women before or during pregnancy to increase the immunity of their infants against this disease during early infancy.

The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public–private collaboration aiming to develop and test a system for rapid vaccine benefit-risk monitoring using existing European healthcare databases. Incidence rate (IR) estimates of vaccination-associated adverse events that are needed to model vaccination risks can be calculated from existing healthcare databases when vaccination (exposure) data are available. We assessed different methods to derive IRs in risk periods following vaccination when exposure data are missing in one database, using estimated IRs and IRRs from other databases for febrile seizures, fever and persistent crying. IRs were estimated for children aged 0–5 years in outcome-specific risk and non-risk periods following the first dose of acellular pertussis (aP) vaccination in four primary care databases and one hospital database. We compared derived and observed IRs in each database using three methods: 1) multiplication of non-risk period IR for database i by IR ratio (IRR) obtained from meta-analysis of IRRs estimated using the self-controlled case-series method, from databases other than i; 2) same method as 1, but multiplying with background IR; and 3) meta-analyses of observed IRs from databases other than i. IRs for febrile seizures were lower in primary care databases than the hospital database. The derived IR for febrile seizures using data from primary care databases was lower than that observed in the hospital database, and using data from the hospital database gave a higher derived IR than that observed in the primary care database. For fever and persistent crying the opposite was observed. We demonstrated that missing IRs for a post-vaccination period can be derived but that the type of database and the method of event data capture can have an impact on potential bias. We recommend IRs are derived using data from similar database types (hospital or primary care) with caution as even this can give heterogeneous results.