Effectiveness of the BNT162b2 mRNA COVID-19 vaccine in pregnancy

Dagan, Noa; Barda, Noam; Biron‐Shental, Tal; Makov-Assif, Maya; Key, Calanit; Kohane, Isaac S.; Hernán, Miguel A.; Lipsitch, Marc; Hernández–Dı́az, Sonia; Reis, Ben Y.; Balicer, Ran D.

doi:10.1038/s41591-021-01490-8

Cited by 239 publications

(254 citation statements)

References 12 publications

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“…Moreover, the number of SARS-CoV-2 specific memory B cells, IFN-g + and/or IL-2 + T cells was lower in vaccinated people over 80 years old than in younger people (87). Besides, BNT162b2 vaccine indicated high efficacy in pregnant women and immunized adolescents aged 12 to 15 years, and the efficacy was similar to that in the general population (88,89). Interestingly, in a study in the UK, antibody responses to BNT162b2 showed that women and the individuals young and previously infected with SARS-CoV-2 had higher IgG levels afterward vaccination (90).…”

Section: Bnt162b2 Mrna Vaccinementioning

confidence: 70%

Immune Evasive Effects of SARS-CoV-2 Variants to COVID-19 Emergency Used Vaccines

et al. 2021

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Coronavirus disease 2019 (COVID-19) pandemic is a serious threat to global public health and social and economic development. Various vaccine platforms have been developed rapidly and unprecedentedly, and at least 16 vaccines receive emergency use authorization (EUA). However, the causative pathogen severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has continued to evolve and mutate, emerging lots of viral variants. Several variants have successfully become the predominant strains and spread all over the world because of their ability to evade the pre-existing immunity obtained after previous infections with prototype strain or immunizations. Here, we summarized the prevalence and biological structure of these variants and the efficacy of currently used vaccines against the SARS-CoV-2 variants to provide guidance on how to design vaccines more rationally against the variants.

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Section: Bnt162b2 Mrna Vaccinementioning

confidence: 70%

Immune Evasive Effects of SARS-CoV-2 Variants to COVID-19 Emergency Used Vaccines

et al. 2021

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“…Observational studies have addressed, fully or partially, each of these limitations of RCTs by comparing rates in unvaccinated people to those in vaccinated people to assess effectiveness during periods of predominance of the Delta (B.1.617.2) variant 22 – 24 , comparing effectiveness between Delta and prior variants 25 – 27 , comparing different vaccine products 22 , 26 , 28 – 31 , or following vaccinated individuals post-vaccination to assess waning 23 , 24 , 27 . Observational studies can also achieve higher sample sizes, thereby making precise estimates of vaccine effectiveness in small subgroups of the population, for example, in distinct 10-year age groups 32 , 33 , in patients with solid organ tumours 34 or in pregnant women 35 .…”

Section: Measuring Breakthrough Infectionsmentioning

confidence: 99%

Section: Measuring Breakthrough Infectionsmentioning

confidence: 99%

“…In settings with well-followed cohorts, such as integrated health-care organizations or cohorts of health-care workers, it has been possible to emulate randomized efficacy trials with cohort studies 27 , 28 , 33 , 35 , 36 . In some such studies, vaccinated and unvaccinated persons are matched on a number of potential confounders in order to make them as similar as possible apart from their vaccine status 33 , 35 . The availability of ‘gold-standard’ evidence from a randomized trial that the effect of Pfizer-BioNTech COVID-19 vaccination begins 10–14 days after the first dose 9 provided a negative control outcome 37 whereby investigators could assess how well vaccinated and unvaccinated individuals had been matched by showing that no difference in the rate of breakthrough infections occurred in this early post-vaccine period 33 , 35 , 36 .…”

Section: Measuring Breakthrough Infectionsmentioning

confidence: 99%

“…In some such studies, vaccinated and unvaccinated persons are matched on a number of potential confounders in order to make them as similar as possible apart from their vaccine status 33 , 35 . The availability of ‘gold-standard’ evidence from a randomized trial that the effect of Pfizer-BioNTech COVID-19 vaccination begins 10–14 days after the first dose 9 provided a negative control outcome 37 whereby investigators could assess how well vaccinated and unvaccinated individuals had been matched by showing that no difference in the rate of breakthrough infections occurred in this early post-vaccine period 33 , 35 , 36 . This approach found consistently high effectiveness in the early months after the second dose across various disease outcomes and across multiple subgroups in the population, with some small exceptions.…”

Section: Measuring Breakthrough Infectionsmentioning

confidence: 99%

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SARS-CoV-2 breakthrough infections in vaccinated individuals: measurement, causes and impact

et al. 2021

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Breakthrough infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in fully vaccinated individuals are receiving intense scrutiny because of their importance in determining how long restrictions to control virus transmission will need to remain in place in highly vaccinated populations as well as in determining the need for additional vaccine doses or changes to the vaccine formulations and/or dosing intervals. Measurement of breakthrough infections is challenging outside of randomized, placebo-controlled, double-blind field trials. However, laboratory and observational studies are necessary to understand the impact of waning immunity, viral variants and other determinants of changing vaccine effectiveness against various levels of coronavirus disease 2019 (COVID-19) severity. Here, we describe the approaches being used to measure vaccine effectiveness and provide a synthesis of the burgeoning literature on the determinants of vaccine effectiveness and breakthrough rates. We argue that, rather than trying to tease apart the contributions of factors such as age, viral variants and time since vaccination, the rates of breakthrough infection are best seen as a consequence of the level of immunity at any moment in an individual, the variant to which that individual is exposed and the severity of disease being considered. We also address key open questions concerning the transition to endemicity, the potential need for altered vaccine formulations to track viral variants, the need to identify immune correlates of protection, and the public health challenges of using various tools to counter breakthrough infections, including boosters in an era of global vaccine shortages.

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COVID-19 mRNA Vaccines During Pregnancy

Kharbanda

Vazquez‐Benitez

2022

JAMA

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SARS-CoV-2 infection during pregnancy is associated with increased risk for maternal morbidity and adverse birth outcomes. 1,2 COVID-19 vaccines are effective for preventing severe disease, including in pregnant populations. 3 Although more than 100 countries recommend COVID-19 vaccination during pregnancy, 4 COVID-19 vaccination in pregnant people has lagged behind that for age-matched, nonpregnant adults. 5,6 As of February 2022, the US Vaccine Safety Datalink estimated that 68% of pregnant individuals have completed the primary COVID-19 vaccine series. 6 Persistent wide disparities in COVID-19 vaccination during pregnancy by race or ethnicity are likely to exacerbate longstanding disparities in maternal morbidity and mortality. 6 Vaccine hesitancy during pregnancy was understandable when COVID-19 vaccines were first authorized, 7 because pregnant people were excluded from the initial COVID-19 vaccine trials. Thus, initial data on pregnancy or birth outcomes after maternal COVID-19 vaccination were limited to inadvertent exposures among trial participants early in pregnancy. The mRNA vaccines were novel and their safety in pregnancy was presumed, but not yet proven. Over the past 14 months, a substantial body of evidence supporting the safety of the mRNA COVID-19 vaccines in pregnancy has accumulated. Observational studies from Norway, Israel, and the US have reported that the mRNA COVID-19 vaccines administered during pregnancy were not associated with increased risk for miscarriage, preterm birth, or other select obstetric and birth outcomes. [8][9][10][11] In this issue of JAMA, 2 population-based observational retrospective studies evaluating outcomes in more than 250 000 pregnancies from 3 countries together provide the strongest evidence to date regarding the safety of COVID-19 vaccines in pregnancy. 12,13 Fell and colleagues 12 used data from the Ontario birth registry, linked with the provincial immunization information system, to identify 97 590 pregnancies eligible for COVID-19 vaccination and with an expected delivery date or live birth from December 14, 2020, to September 30, 2021. Of these pregnant individuals, 23% were vaccinated during pregnancy; most were vaccinated in third trimester. Compared with those vaccinated after pregnancy and, in separate analyses, compared with those who were unvaccinated during pregnancy, COVID-19 vaccination during pregnancy was not associated with increased risks for postpartum hemorrhage, chorioamnionitis, cesarean delivery, neonatal care admission, or low Apgar score.

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Effectiveness of the BNT162b2 mRNA COVID-19 vaccine in pregnancy

Cited by 239 publications

References 12 publications

Immune Evasive Effects of SARS-CoV-2 Variants to COVID-19 Emergency Used Vaccines

Immune Evasive Effects of SARS-CoV-2 Variants to COVID-19 Emergency Used Vaccines

SARS-CoV-2 breakthrough infections in vaccinated individuals: measurement, causes and impact

COVID-19 mRNA Vaccines During Pregnancy

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