Pertussis Vaccination In Pregnancy Research Articles

Transplacental transfer of maternal antibodies following immunization with recombinant pertussis vaccines during pregnancy: Real-world evidence

Aim/objectiveThis study investigates placental antibody transfer following recombinant pertussis vaccination in pregnancy in a real-world setting. MethodsThis postmarketing observational study recruited pregnant women vaccinated with monovalent recombinant acellular pertussis (aP) vaccine (aPgen; n = 199) or combined to tetanus-diphtheria (TdaPgen; n = 200), or Td-vaccine only (n = 54). Pregnancy, delivery, and neonatal outcomes were assessed. Cord blood was collected postdelivery and pertussis toxin (PT)-IgG, filamentous hemagglutinin (FHA)-IgG, and PT-neutralizing antibodies (PT-Nab) were assessed. ResultsNo adverse pregnancy, delivery, or neonatal outcomes attributed to aPgen, TdaPgen, or Td vaccination were reported. High anti-PT antibody levels were detected in cord samples from women vaccinated with aPgen (geometric mean concentration [GMC] PT-IgG 206.1 IU/ml, 95% confidence intervals [CI]: 164.3-258.6; geometric mean titer [GMT] PT-Nab 105.3 IU/ml, 95% CI: 81.7-135.8) or TdaPgen (GMC PT-IgG 153.1 IU/ml, 95% CI: 129.1-181.5; GMT PT-Nab 81.5 IU/ml, 95% CI: 66.4-100.0). In the Td-only group, anti-PT antibodies were low (GMC PT-IgG 6.5 IU/ml, 95% CI: 4.9-8.8; GMT PT-Nab 3.8 IU/ml, 95% CI: 2.8-5.1). The same was found for FHA-IgG. Recombinant pertussis vaccination at <27 or 27-36 weeks gestation induced similar cord pertussis antibody levels. ConclusionThis first real-world study confirms that recombinant pertussis vaccination in the second or third trimester of pregnancy results in high levels of passive immunity in infants.Thai Clinical Trial Registry: TCTR20200528006.

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.

Impact of pregnancy vaccine uptake and socio-demographic determinants on subsequent childhood Measles, Mumps and Rubella vaccine uptake: A UK birth cohort study

BackgroundWe examined the association between socio-demographic determinants and uptake of childhood Measles, Mumps & Rubella (MMR) vaccines and the association between pregnant women’s pertussis vaccine uptake and their children’s MMR vaccine uptake. MethodsWe used nationally-representative linked mother-baby electronic records from the United Kingdom’s Clinical-Practice-Research-Datalink. We created a birth cohort of children born between 01.01.2000 and 12.12.2020. We estimated the proportion vaccinated with first MMR vaccine by age 2 years and first and second MMR vaccines by age 5 years. We used survival-analysis and Cox proportional hazard models to examine the association between deprivation, ethnicity and maternal age and pertussis vaccination in pregnancy and children’s MMR uptake. ResultsOverall, 89.4 % (710,797/795,497) of children had first MMR by age 2 years and 92.6 % (736,495/795,497) by age 5 years. Among children still in the cohort when second MMR was due, 85.9 % (478,480/557,050) had two MMRs by age 5 years. Children from the most-deprived areas, children of Black ethnicity and children of mothers aged < 20 years had increased risk of being unvaccinated compared with children from the least-deprived areas, White children and children of mothers aged 31–40 years: first MMR by 5 years, adjusted Hazard Ratios (HR):0.86 (CI:0.85–0.87), HR:0.87 (CI:0.85–0.88) & HR:0.89 (CI:0.88–0.90) respectively. Deprivation was the determinant associated with the greatest risk of missed second MMR: adjusted HR:0.82 (CI:0.81–0.83). Children of mothers vaccinated in pregnancy were more likely than children of unvaccinated mothers to have MMR vaccines after adjusting for ethnicity, deprivation, and maternal age (First and Second MMRs adjusted HRs:1.43 (CI:1.41–1.45), 1.49 (CI:1.45–1.53). ConclusionChildren from most-deprived areas are less likely to have MMR vaccines compared with children from least-deprived areas. Mothers who take up pregnancy vaccines are more likely to have their children vaccinated with MMR. Healthcare services should promote and facilitate access to both maternal and childhood vaccines during pregnancy.

Inequity of antenatal influenza and pertussis vaccine coverage in Australia: the Links2HealthierBubs record linkage cohort study, 2012–2017

BackgroundPregnancy and early infancy are increased risk periods for severe adverse effects of respiratory infections. Aboriginal and/or Torres Strait Islander (respectfully referred to as First Nations) women and children in Australia bear a disproportionately higher burden of respiratory diseases compared to non-Indigenous women and infants. Influenza vaccines and whooping cough (pertussis) vaccines are recommended and free in every Australian pregnancy to combat these infections. We aimed to assess the equity of influenza and/or pertussis vaccination in pregnancy for three priority groups in Australia: First Nations women; women from culturally and linguistically diverse (CALD) backgrounds; and women living in remote areas or socio-economic disadvantage.MethodsWe conducted individual record linkage of Perinatal Data Collections with immunisation registers/databases between 2012 and 2017. Analysis included generalised linear mixed model, log-binomial regression with a random intercept for the unique maternal identifier to account for clustering, presented as prevalence ratios (PR) and 95% compatibility intervals (95%CI).ResultsThere were 445,590 individual women in the final cohort. Compared with other Australian women (n = 322,848), First Nations women (n = 29,181) were less likely to have received both recommended antenatal vaccines (PR 0.69, 95% CI 0.67–0.71) whereas women from CALD backgrounds (n = 93,561) were more likely to have (PR 1.16, 95% CI 1.10–1.13). Women living in remote areas were less likely to have received both vaccines (PR 0.75, 95% CI 0.72–0.78), and women living in the highest areas of advantage were more likely to have received both vaccines (PR 1.44, 95% CI 1.40–1.48).ConclusionsCompared to other groups, First Nations Australian families, those living in remote areas and/or families from lower socio-economic backgrounds did not receive recommended vaccinations during pregnancy that are the benchmark of equitable healthcare. Addressing these barriers must remain a core priority for Australian health care systems and vaccine providers. An extension of this cohort is necessary to reassess these study findings.

Optimising the timing of whooping cough immunisation in mums (OpTIMUM) through investigating pertussis vaccination in pregnancy: an open-label, equivalence, randomised controlled trial

Pertussis vaccination in pregnancy is recommended in many countries to provide protection to young infants. The best timing for this vaccination is uncertain. In the UK, vaccination is recommended between 16 weeks and 32 weeks of gestation. In this trial we aimed to investigate the equivalence of three time periods for pertussis vaccination in pregnancy. In this open-label, equivalence, randomised controlled trial to investigate equivalence of different time windows for pertussis vaccination in pregnancy, participants were randomly assigned (1:1:1 ratio) to receive a pertussis-containing vaccine (Boostrix-inactivated poliovirus vaccine) in one of three gestational age groups, comprising group 1 (≤23 weeks + 6 days), group 2 (24-27 weeks + 6 days), and group 3 (28-31 weeks + 6 days) using a computer-generated randomisation list. The primary outcome was concentration of pertussis-specific antibodies in the infant born at term at birth. Maternal blood sampling was done before and 2 weeks after vaccination and at delivery, together with a cord sample, and an infant sample was collected at least 4 weeks after primary vaccination. Reactogenicity was assessed for 7 days after vaccination. This trial was registered with ClinicalTrials.gov (NCT03908164). Between May 7, 2019, and Feb 13, 2020, of 1010 women assessed for eligibility, 364 women were recruited and 351 received the intervention (120 in group 1, 119 in group 2, and 112 in group 3). Equivalence of time periods was demonstrated for anti-pertussis toxin and anti-pertactin IgG concentrations. The cord blood geometric mean concentrations of anti-filamentous haemagglutinin IgG were higher with increasing gestational age at vaccination, such that for infants in group 1 (≤23 weeks + 6 days), equivalence to group 3 (28-31 weeks + 6 days) was not shown. Reported rates of fever were similar between study groups. Pertussis vaccination at three different time intervals in pregnancy resulted in equivalent concentrations of IgG antibodies in infants against two of the three pertussis antigens assessed. Overall, these findings support recommendations to vaccinate any time between 16 weeks and 32 weeks of gestation. The Thrasher Research Fund and the National Immunisation Schedule Evaluation Consortium through the National Institute for Health and Care Research policy research programme.

Effectiveness of pertussis vaccination in pregnancy to prevent hospitalisation in infants aged

BackgroundPERTINENT is an active hospital-based surveillance system for pertussis in infants. In 2019, four of the six participating European countries recommended pertussis vaccination in pregnancy. Among infants aged <2 months, we measured the vaccine effectiveness (VE) in pregnancy; among infants aged 2–11 months, VE of vaccination in pregnancy and of primary vaccination (PV). MethodsFrom December 2015 to 2019, we included all infants aged <1 year presenting with pertussis-like symptoms. Using a test-negative-design, cases were infants testing positive for Bordetella pertussis by PCR or culture. Controls were those testing negative for all Bordetella species. Vaccinated mothers were those who received vaccine in pregnancy. Vaccinated infants were those who received ≥1 dose of PV > 14 days before symptom onset. We excluded infants with unknown maternal or PV status or with mothers vaccinated ≤14 days before delivery. We calculated pooled VE as 100 * (1-odds ratio of vaccination) adjusted for study site, onset date in quarters and infants’ age group. ResultsOf 829 infants presenting with pertussis-like symptoms, 336 (41%) were too young for PV. For the VE in pregnancy analysis, we included 75 cases and 201 controls. Vaccination in pregnancy was recorded for 9 cases (12%) and 92 controls (46%), adjusted VE was between 75% [95%CI: 35–91%] and 88% [95%CI: 57–96%].Of 493 infants eligible for PV, we included 123 cases and 253 controls. Thirty-one cases and 98 controls recorded both PV with ≥ 1 dose and vaccination in pregnancy, adjusted VE was between 74% [95%CI: 33–90] and 95% [95%CI: 69–99]; 27 cases and 53 controls recorded PV only, adjusted VE was between 68% [95%CI: 27–86] and 94% [95%CI: 59–99]. ConclusionOur findings suggest that vaccination in pregnancy reduces pertussis incidence in infants too young for PV. In infants aged 2–11 months, PV only and both PV and vaccination in pregnancy provide significant protection against severe pertussis.

Women's views and experiences of accessing pertussis vaccination in pregnancy and infant vaccinations during the COVID-19 pandemic: A multi-methods study in the UK

BackgroundCOVID-19 changed access to healthcare, including vaccinations, in the United Kingdom (UK). This study explored UK women’s experiences of accessing pertussis vaccination during pregnancy and infant vaccinations during COVID-19. MethodsAn online cross-sectional survey was completed, between 3rd August-11th October 2020, by 1404 women aged 16+ years who were pregnant at some point after the first UK lockdown from March 23rd, 2020. Ten follow-up semi-structured interviews were conducted. ResultsMost women surveyed were pregnant (65.7%) and a third postnatal (34.3%). Almost all women (95.6%) were aware that pertussis vaccination is recommended in pregnancy. Most pregnant (72.1%) and postnatal women (84.0%) had received pertussis vaccination; however, access issues were reported.Over a third (39.6%) of women had a pregnancy vaccination appointment changed. COVID-19 made it physically difficult to access pregnancy vaccinations for one fifth (21.5%) of women and physically difficult to access infant vaccinations for almost half of women (45.8%). Nearly half of women (45.2%) reported feeling less safe attending pregnancy vaccinations and over three quarters (76.3%) less safe attending infant vaccinations due to COVID-19. The majority (94.2%) felt it was important to get their baby vaccinated during COVID-19.Pregnant women from ethnic-minorities and lower-income households were less likely to have been vaccinated. Minority-ethnicity women were more likely to report access problems and feeling less safe attending vaccinations for both themselves and their babies.Qualitative analysis found women experienced difficulties accessing antenatal care and relied on knowledge from previous pregnancies to access vaccines in pregnancy. ConclusionDuring the ongoing and future pandemics, healthcare services should prioritise equitable access to routine vaccinations, including tailoring services for ethnic-minority families who experience greater barriers to vaccination.

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

IntroductionThe recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalisation rate for pertussis in children under one year of age before and after the implementation of the vaccination programme. MethodsObservational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalisation rate of patients under one year of age of the period prior to the vaccination programme (2008−2013) was compared with the period with vaccination programme (2014−2019) in the total of children under one year of age and in 2 subgroups: children under 3 months and between 3−11 months. ResultsHospitalization rate was significantly lower in the period with vaccination programme in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1000 person-years and 6.47 vs. 13.11 per 1000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36−0.73) for children under one year of age; 0.49 (95% CI 0.32−0.75) for those younger than 3 months and 0.56 (95% CI 0.30−1.03) for those with 3−11 months. No statistically significant differences were observed in the clinical severity between both periods. ConclusionThe introduction of the pertussis vaccination programme in pregnancy was associated with a global lower hospitalisation rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Do intentions lead to action? Results of a longitudinal study assessing determinants of Tdap vaccine uptake during pregnancy in Quebec, Canada

BackgroundIn Canada, vaccination against pertussis (Tdap) during pregnancy has been recommended since 2018, with suboptimal uptake. We aimed to assess the determinants of intention and uptake of Tdap vaccine among pregnant women in Quebec.MethodsParticipants (< 21 weeks of pregnancy) were recruited in four Quebec regions. Two online surveys were administered during pregnancy (< 21 weeks and > 35 weeks). One measured vaccination intention and the other assessed the actual decision. Questionnaires were informed by the Theory of Planned Behaviour (TPB). We used logistic multivariate analysis to identify determinants of Tdap vaccination uptake during pregnancy using responses to both questionnaires.ResultsA total of 741 women answered the first survey and 568 (76.7%), the second survey. In the first survey most participants intended to receive the Tdap vaccine during their pregnancy (76.3%) and in the second survey, 82.4% reported having been vaccinated against Tdap during their pregnancy. In multivariate analysis, the main determinants of vaccine uptake were: a recommendation from a healthcare provider (OR = 7.6), vaccine intention (OR = 6.12), social norms (or thinking that most pregnant women will be vaccinated (OR = 3.81), recruitment site (OR = 3.61 for General Family Medicine unit) perceived behavioral control (or low perceived barriers to access vaccination services, (OR = 2.32) and anticipated feeling of guilt if not vaccinated (OR = 2.13). Safety concerns were the main reason for not intending or not receiving the vaccine during pregnancy.ConclusionWe observed high vaccine acceptance and uptake of pertussis vaccine in pregnancy. The core components of the TPB (intention, social norms and perceived behavioral control) were all predictors of vaccine uptake, but our multivariate analysis also showed that other determinants were influential: being sufficiently informed about Tdap vaccination, not having vaccine safety concerns, and anticipated regret if unvaccinated. To ensure high vaccine acceptance and uptake in pregnancy, strong recommendations by trusted healthcare providers and ease of access to vaccination services remain instrumental.

Effect of pertussis vaccine in pregnancy and COVID-19 pandemic in the cases of wooping cough

BackgroundWhooping cough has had an increased incidence and severity specially in infants and maternal immunization has been implemented as a prevention strategy. COVID-19 pandemic seems to decrease the incidence of other respiratory diseases. MethodsRetrospective study from 2012 to 2021 to assess the influence of pertussis maternal immunizations and the first year of COVID-19 pandemic in the cases of whooping cough. Results960 suspected cases from primary care and hospital, with 130 cases (104 children and 26 adults) being diagnosed of whooping cough. In the post-vaccination period, a reduction in the cases and severity in infants up to 6 months old was observed as well as in the pertussis diagnosis in adult women. There were no whooping cough cases during the COVID-19 period. ConclusionsBoth the pertussis vaccination in pregnancy and the first year of the COVID-19 pandemic have decreased the number of pertussis cases.

Association between social vulnerability and influenza and tetanus-diphtheria-acellular pertussis vaccination in pregnant and postpartum individuals

Despite current guidelines recommending universal vaccination, the frequency of vaccination in pregnancy for influenza and tetanus-diphtheria-acellular pertussis remains low. This study aimed to evaluate the association between community-level social vulnerability and influenza and anticipated tetanus-diphtheria-acellular pertussis vaccinations among pregnant and postpartum individuals. We conducted a cross-sectional survey of vaccine hesitancy in the peripartum period among pregnant and postpartum participants enrolled in prenatal care at a single tertiary care center from March 22, 2021, to April 02, 2021. Participant addresses were geocoded using ArcGIS and linked at the census tract level. The primary exposure was community-level social vulnerability as measured by the US Centers for Disease Control and Prevention's Social Vulnerability Index. This index incorporates 15 census variables to produce a composite score and subscores across 4 major thematic domains (socioeconomic status, household composition and disability, minority status and language, and housing type and transportation). The scores range from 0 to 1, with higher values indicating greater social vulnerability. The primary outcomes were self-reported influenza vaccination during the current influenza season and having received or planning to receive the tetanus-diphtheria-acellular pertussis vaccination in pregnancy. We used multivariable logistic regression and adjusted for age, self-reported race and ethnicity, parity, trimester of pregnancy, and chronic comorbid conditions. Of 456 assessed individuals (95% pregnant individuals and 5% postpartum individuals), the frequency of influenza vaccination was 58% (95% confidence interval, 53-62), and the anticipated tetanus-diphtheria-acellular pertussis vaccination was 72% (95% confidence interval, 68-76). Individuals from communities with a higher Social Vulnerability Index were less likely to report vaccination in pregnancy than those from communities with a lower Social Vulnerability Index. Specifically, for each 0.1-unit increase in the Social Vulnerability Index, the odds of influenza vaccination (adjusted odds ratio, 0.23; 95% confidence interval, 0.11-0.46) and anticipated tetanus-diphtheria-acellular pertussis vaccination (adjusted odds ratio, 0.24; 95% confidence interval, 0.11-0.53) decreased by >70%. By domain, the Social Vulnerability Index subscores of socioeconomic status (influenza adjusted odds ratio, 0.20 [95% confidence interval, 0.10-0.40]; tetanus-diphtheria-acellular pertussis adjusted odds ratio, 0.25 [95% confidence interval, 0.12-0.53]) and housing type and transportation (influenza adjusted odds ratio, 0.41 [95% confidence interval, 0.19-0.84; tetanus-diphtheria-acellular pertussis adjusted odds ratio, 0.39 [95% confidence interval, 0.18-0.87) were inversely associated with a lower odds of influenza and tetanus-diphtheria-acellular pertussis vaccinations. Pregnant and postpartum individuals living in areas with higher social vulnerability were less likely to report influenza and anticipated tetanus-diphtheria-acellular pertussis vaccinations in pregnancy. The Social Vulnerability Index could be used as a tool to improve vaccine equity and address disparities in vaccination in pregnancy.

Determination of Maternal and Infant Immune Responses to Pertussis Vaccination in Pregnancy.

The Bordetella pertussis bacterium is the causative agent of whooping cough (pertussis disease). Following recent outbreaks of pertussis, disproportionately affecting young infants, several countries have introduced maternal pertussis vaccination strategies, aimed at boosting transplacental transfer of protective antibodies during pregnancy. Given historical associations between high maternal antibody and blunted infant responses to vaccination, subsequent research studies have investigated the impact of maternal pertussis vaccine on infant humoral responses. However, far less is known about the potential impact of the vaccine on innate immunity. Here, we describe methods to detect in vitro cellular responses to B. pertussis in mothers and their infants using a B. pertussis stimulation assay and multiplex cytokine assays to address this research question.

Assessment of knowledge and attitude towards influenza and pertussis vaccination in pregnancy and factors affecting vaccine uptake rates: a cross-sectional survey.

Assessment of knowledge and attitude towards influenza and pertussis vaccination in pregnancy and factors affecting vaccine uptake rates: a cross-sectional survey.

Pertussis vaccination in pregnancy - current data on safety and effectiveness.

Whooping cough/pertussis is a respiratory infection caused by the bacteria Bordetella pertussis and Bordetella parapertussis. The World Health Organization (WHO) has identified whooping cough as one of the least controlled diseases in all age groups. Clinically, the catarrhal phase manifests itself as flu-like, nonspecific symptoms: cough, runny nose, mild fever, which, regrettably, makes early diagnosis difficult. The severe course is more specific (an audible inspiratory whoop followed by paroxysmal cough and vomiting). Currently, in Poland the highest percentage of cases is observed in children aged 0-4 years, followed by children over 15 years of age, with peaks among teens and seniors. Notably, hospitalization, morbidity and mortality rates are considerable in children (especially infants). Vaccinating pregnant women against pertussis provides approximately 90% protection to infants in their first two months of life. It is an effective form of preventing pertussis in infants. Moreover, it is safe for pregnant women and their children. The Advisory Committee on Immunization Practices (ACIP) recommends Tdap vaccination to every pregnant woman between 27-36 weeks of pregnancy.

Evolución de los casos de tosferina tras la vacunación de la embarazada y la pandemia COVID-19

BackgroundWhooping cough has had an increased incidence and severity specially in infants and maternal immunization has been implemented as a prevention strategy. COVID-19 pandemic seems to decrease the incidence of other respiratory diseases. MethodsRetrospective study from 2012 to 2021 to assess the influence of pertussis maternal immunizations and the first year of COVID-19 pandemic in the cases of whooping cough. Results960 suspected cases from primary care and hospital, with 130 cases (104 children and 26 adults) being diagnosed of whooping cough. In the post-vaccination period, a reduction in the cases and severity in infants up to 6 months old was observed as well as in the pertussis diagnosis in adult women. There were no whooping cough cases during the COVID-19 period. ConclusionsBoth the pertussis vaccination in pregnancy and the first year of the COVID-19 pandemic have decreased the number of pertussis cases.

Optimising the Timing of whooping cough Immunisation in MUMs: a randomised controlled trial investigating the timing of pertussis vaccination in pregnancy (OpTIMUM): a protocol paper

Background: Pertussis is a highly infectious respiratory illness caused by the bacteria Bordetella pertussis. A resurgence of pertussis, even in countries with good vaccine coverage, has led to an increase in infant deaths. In response to this, many countries have introduced pertussis vaccination in pregnancy. This strategy is effective at preventing infant disease, but there remains uncertainty about what gestational timing is best to ensure maximal protection of the infant. These uncertainties are the rationale for this randomised controlled trial and a sub-study investigating pertussis-specific antibody in breastmilk. Protocol: We will recruit 354 pregnant women and will randomise them to receive their pertussis vaccination in one of three gestational age windows: ≤23+6, 24-27+6 and 28-31+6 weeks of gestation. Vaccination will be with Boostrix-IPV® and participants will be asked to complete a symptom diary for seven days following vaccination. Blood sampling will be performed prior to vaccination, two weeks following vaccination and at the time of delivery. A cord blood sample will be collected at delivery and a blood sample collected from the infant 4-10 weeks after completion of the primary immunisations. Individuals participating in the breastmilk sub-study will provide a sample of colostrum within 48 hours of delivery and samples of breastmilk at two weeks and around five-six months. Blood samples will be analysed using enzyme linked immunosorbent assay (ELISA) techniques for pertussis toxin, filamentous haemagglutinin and pertactin. A subset of serum samples will also be analysed using a functional assay. Colostrum and breastmilk samples will be analysed using functional assays. Discussion: Although pertussis vaccination has been shown to be safe and effective in pregnancy there remains debate about the optimal timing for the administration during pregnancy. This study will investigate antibody responses in serum and breastmilk when vaccination is performed in three different time periods. Clinicaltrials.gov registration: NCT03908164 (09/04/2019)

Impacto de la vacunación de las embarazadas frente a la tosferina en las hospitalizaciones de menores de un año en un hospital de tercer nivel de Cataluña

IntroductionThe recommendation for pertussis vaccination in pregnancy was established in Catalonia in February 2014. The objective of this study was to compare the hospitalization rate for pertussis in children under one year of age before and after the implementation of the vaccination program. MethodsObservational and retrospective study of patients under one year of age admitted to hospital with a diagnosis of pertussis. The hospitalization rate of patients under one year of age of the period prior to the vaccination program (2008-2013) was compared with the period with vaccination program (2014-2019) in the total of children under one year of age and in 2subgroups: children under 3 months and between 3-11 months. ResultsHospitalization rate was significantly lower in the period with vaccination program in children under one year of age and specifically in children under 3 months (2.43 vs. 4.72 per 1,000 person-years and 6.47 vs. 13.11 per 1,000 person-years, respectively). The rate ratios were: 0.51 (95% CI 0.36-0.73) for children under one year of age; 0.49 (95% CI 0.32-0.75) for those younger than 3 months and 0.56 (95% CI 0.30-1.03) for those with 3-11 months. No statistically significant differences were observed in the clinical severity between both periods. ConclusionThe introduction of the pertussis vaccination program in pregnancy was associated with a global lower hospitalization rate for pertussis in children under one year of age and specifically in those under 3 months of age.

Barriers and Facilitators Associated With Vaccine Acceptance and Uptake Among Pregnant Women in High Income Countries: A Mini-Review.

Vaccination during pregnancy is a safe and effective intervention to protect women from potentially severe consequences of influenza and reduce risk of influenza and pertussis in their infants. However, coverage remains variable. In this mini-review we update findings from a 2015 systematic review to describe results from recent studies in high income countries on the uptake of influenza and pertussis vaccination in pregnancy, reasons for vaccine hesitancy and barriers to increasing uptake, from maternal and healthcare provider (HCP) perspectives. Studies reported highly variable uptake (from 0% to 78%). A main facilitator for uptake among pregnant women was receiving a recommendation from their HCP. However, studies showed that HCP awareness of guidelines did not consistently translate into them recommending vaccines to pregnant women. Safety concerns are a well-established barrier to uptake/coverage of maternal immunization; 7%-52% of unvaccinated women gave safety concerns as a reason but these were also present in vaccinated women. Knowledge/awareness gaps among pregnant women and lack of confidence among HCPs to discuss vaccination were both important barriers. Several studies indicated that midwives were more likely to express safety concerns than other HCPs, and less likely to recommend vaccination to pregnant women. Women who perceived the risk of infection to be low were less likely to accept vaccination in several studies, along with women with prior vaccine refusal. Findings highlight the importance of further research to explore context-specific barriers to vaccination in pregnancy, which may include lack of vaccine confidence among pregnant woman and HCPs, and policy and structural factors.

Systematic review: pertussis vaccine in pregnancy

Systematic review: pertussis vaccine in pregnancy

Systematic review and meta-analysis of the effect of pertussis vaccine in pregnancy on the risk of chorioamnionitis, non-pertussis infectious diseases and other adverse pregnancy outcomes

BackgroundSeveral countries have introduced maternal immunisation with pertussis vaccine to provide protection against pertussis in early infancy. There is increasing interest in non-specific effects of vaccines including that non-live vaccines may enhance susceptibility to non-targeted infections in females. Some studies have shown increased risk of chorioamnionitis among women receiving pertussis vaccine during pregnancy. We aimed to conduct a systematic review and meta-analysis of the effect of maternal pertussis immunisation on the risk of chorioamnionitis, as well as the secondary outcomes of non-pertussis infections in women, non-pertussis infections in infants, spontaneous abortion or stillbirth, maternal death and infant death. MethodsWe searched PubMed and Embase for articles published until January 14, 2021. We screened articles for eligibility and extracted data using Covidence. Quality was assessed using Cochrane RoB tool and Newcastle-Ottawa Scale. Data were imported into RevMan for pooling and conduction of a meta-analysis stratified by study type. Outcomes are presented as risk ratios. ResultsWe identified 13 observational studies and six randomized controlled trials eligible for inclusion. We pooled data on chorioamnionitis from six observational studies and found maternal pertussis vaccine (mostly compared with other maternal immunizations with non-live vaccines) to be associated with an increased risk among the pertussis vaccinated women, RR = 1.27 [CI 95%: 1.14–1.42]. We found no difference in the analysis of our secondary outcomes of non-pertussis infections, spontaneous abortion or stillbirth and death. ConclusionWe found an increased risk of chorioamnionitis among women who received pertussis vaccine in pregnancy. The large number of women receiving pertussis vaccine during pregnancy, as well as the growing evidence of non-live vaccines causing increased susceptibility to infections, indicates a need for further randomised trials to assess potential adverse effects of maternal immunisation with pertussis-containing vaccines.