Dataset Information

Effectiveness of BNT162b2 Vaccination During Pregnancy in Preventing Hospitalization for SARS-CoV-2 in Infants.

ABSTRACT:

Objective

To Assessthe clinical effectiveness of the BNT162b2 vaccine during pregnancy in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hospitalizations of infants.

Study design

A retrospective, multicenter, 1:3 case-control (test-negative) study. Symptomatic hospitalized infants <6 months, with positive SARS-CoV-2 polymerase chain reaction (PCR) test between 1/3/2021-31/11/2021 were matched by age and time to negative controls, hospitalized with symptoms compatible with SARS-CoV-2 infection. Mothers were defined as fully vaccinated; received 2 doses of BNT162b2 with the second given 2 weeks to 6 months before delivery, or partially vaccinated; received only one dose or 2 doses with the second given >6 months or <2 weeks before delivery. Severe SARS-CoV-2 was defined as need for assisted ventilation.

Results

116 SARS-CoV-2 positive infants were matched to 348 negative controls with symptoms compatible with SARS-CoV-2 infection. The effectiveness of fully vaccinated mothers was 61.6% (CI: 31.9-78.4) and the effectiveness of partially vaccinated mothers was not significant. Effectiveness was higher in infants 0-2 vs. 3-6 months of age. The effectiveness (57.1%, CI: 22.8-76.4) was similar when excluding mothers who were infected with SARS-CoV-2 during pregnancy. OR of severe infection in infants born to unvaccinated versus fully vaccinated mothers was 5.8.

Conclusions

At least 2 doses of BNT162b2 vaccine administered during the second or third trimester of pregnancy had an effectiveness of 61.6% in reduction of hospitalization for SARS-CoV-2 infection in infants <6 months.

SUBMITTER: Danino D

PROVIDER: S-EPMC9568274 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effectiveness of BNT162b2 Vaccination During Pregnancy in Preventing Hospitalization for Severe Acute Respiratory Syndrome Coronavirus 2 in Infants.

Danino Dana D Ashkenazi-Hoffnung Liat L Diaz Alejandro A Erps Amir Dov AD Eliakim-Raz Noa N Avni Yonat Shemer YS Greenberg David D Givon-Lavi Noga N Youngster Ilan I

The Journal of pediatrics 20221015

<h4>Objective</h4>To assess the clinical effectiveness of the BNT162b2 vaccine during pregnancy in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hospitalizations of infants.<h4>Study design</h4>A retrospective, multicenter, 1:3 case-control (test-negative) study. Symptomatic hospitalized infants less than 6 months of age, with a positive SARS-CoV-2 polymerase chain reaction test between January 3, 2021, and March 11, 2021, were matched by age and time to negative contro ...[more]

PMID: 36252864

Similar Datasets

Project description:ImportancePregnant women are recommended to receive COVID-19 vaccination to reduce risk of severe COVID-19. Whether vaccination during pregnancy also provides passive protection to infants after birth remains unclear.ObjectiveTo determine whether COVID-19 vaccination in pregnancy was associated with reduced risk of COVID-19 in infants up to age 4 months during COVID-19 pandemic periods dominated by Delta and Omicron variants.Design, setting, and participantsThis nationwide, register-based cohort study included all live-born infants born in Norway between September 1, 2021, and February 28, 2022.ExposuresMaternal messenger RNA COVID-19 vaccination during second or third trimester compared with no vaccination before or during pregnancy.Main outcomes and measuresThe risk of a positive polymerase chain reaction test result for SARS-CoV-2 during an infant's first 4 months of life by maternal vaccination status during pregnancy with either dose 2 or 3 was estimated, as stratified by periods dominated by the Delta variant (between September 1 and December 31, 2021) or Omicron variant (after January 1, 2022, to the end of follow-up on April 4, 2022). A Cox proportional hazard regression was used, adjusting for maternal age, parity, education, maternal country of birth, and county of residence.ResultsOf 21 643 live-born infants, 9739 (45.0%) were born to women who received a second or third dose of a COVID-19 vaccine during pregnancy. The first 4 months of life incidence rate of a positive test for SARS-CoV-2 was 5.8 per 10 000 follow-up days. Infants of mothers vaccinated during pregnancy had a lower risk of a positive test compared with infants of unvaccinated mothers and lower risk during the Delta variant-dominated period (incidence rate, 1.2 vs 3.0 per 10 000 follow-up days; adjusted hazard ratio, 0.29; 95% CI, 0.19-0.46) compared with the Omicron period (incidence rate, 7.0 vs 10.9 per 10 000 follow-up days; adjusted hazard ratio, 0.67; 95% CI, 0.57-0.79).Conclusions and relevanceThe results of this Norwegian population-based cohort study suggested a lower risk of a positive test for SARS-CoV-2 during the first 4 months of life among infants born to mothers who were vaccinated during pregnancy. Maternal COVID-19 vaccination may provide passive protection to young infants, for whom COVID-19 vaccines are currently not available.

Project description:ImportanceData about the safety of vaccines against SARS-CoV-2 during pregnancy are limited.ObjectiveTo examine the risk of adverse pregnancy outcomes after vaccination against SARS-CoV-2 during pregnancy.Design, setting, and participantsThis registry-based retrospective cohort study included 157 521 singleton pregnancies ending after 22 gestational weeks from January 1, 2021, until January 12, 2022 (Sweden), or January 15, 2022 (Norway). The Pregnancy Register in Sweden and the Medical Birth Registry of Norway were linked to vaccination and other registries for identification of exposure and background characteristics.ExposuresData on mRNA vaccines-BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)-and 1 viral vector vaccine-AZD1222 (AstraZeneca)-were collected from national vaccination registries.Main outcomes and measuresThe risk of preterm birth and stillbirth was evaluated using Cox regression models, with gestational day as the time metric and vaccination as a time-dependent exposure variable. The risk of small for gestational age, low Apgar score, and neonatal care admission was evaluated using logistic regression. Random-effects meta-analysis was used to combine results between countries.ResultsAmong the 157 521 singleton births included in the study (103 409 in Sweden and 54 112 in Norway), the mean maternal age at the time of delivery was 31 years, and 28 506 (18%) were vaccinated against SARS-CoV-2 (12.9% with BNT162b2, 4.8% with mRNA-1273, and 0.3% with AZD1222) while pregnant. A total of 0.7%, 8.3%, and 9.1% of individuals delivering were vaccinated during the first, second, and third trimester, respectively. Vaccination against SARS-CoV-2 was not significantly associated with increased risk of preterm birth (6.2 vs 4.9 per 10 000 pregnancy days; adjusted hazard ratio [aHR], 0.98 [95% CI, 0.91 to 1.05]; I2 = 0%; P for heterogeneity = .60), stillbirth (2.1 vs 2.4 per 100 000 pregnancy days; aHR, 0.86 [95% CI, 0.63 to 1.17]), small for gestational age (7.8% vs 8.5%; difference, -0.6% [95% CI, -1.3% to 0.2%]; adjusted OR [aOR], 0.97 [95% CI, 0.90 to 1.04]), low Apgar score (1.5% vs 1.6%; difference, -0.05% [95% CI, -0.3% to 0.1%]; aOR, 0.97 [95% CI, 0.87 to 1.08]), or neonatal care admission (8.5% vs 8.5%; difference, 0.003% [95% CI, -0.9% to 0.9%]; aOR, 0.97 [95% CI, 0.86 to 1.10]).Conclusions and relevanceIn this population-based study conducted in Sweden and Norway, vaccination against SARS-CoV-2 during pregnancy, compared with no SARS-CoV-2 vaccination during pregnancy, was not significantly associated with an increased risk of adverse pregnancy outcomes. The majority of the vaccinations were with mRNA vaccines during the second and third trimesters of pregnancy, which should be considered in interpreting the findings.