ABSTRACT
There are limited data regarding the safety of COVID-19 vaccines in early pregnancy. This may contribute to vaccine hesitancy in people who are pregnant, or who are planning pregnancy. We conducted a population-level matched cohort study assessing associations between COVID-19 vaccination and miscarriage (pregnancy loss prior to 20 weeks gestation) and ectopic pregnancy. We used electronic health records of all female residents in Scotland who were vaccinated between 6 weeks preconception and 19 weeks 6 days gestation (for miscarriage; n = 18,780) or 2 weeks 6 days gestation (for ectopic; n = 10,570). Primary analyses used unvaccinated women from the pre-pandemic period as controls (historical controls) matched (3:1) on maternal age, gestational age at vaccination, and season of conception; with adjustment for maternal deprivation level, rural/urban status and clinical vulnerability. Supplementary analyses used unvaccinated women from the pandemic period as controls (contemporary controls). Analyses of outcomes following SARS-CoV-2 infection were undertaken with infection rather than vaccination as the exposure. Following COVID-19 vaccination, the rate of miscarriage was 9.1% (n = 1,716) and ectopic pregnancy 1.2% (n = 126). Primary analyses found no association between vaccination and miscarriage (adjusted Odds Ratio [aOR] = 1.02, 95% Confidence Interval [CI] = 0.96–1.09) or ectopic pregnancy (aOR = 1.13, 95% CI = 0.92–1.38). Primary analyses also found no association between SARS-CoV-2 infection and miscarriage or ectopic pregnancy. Results of supplementary analyses were similar to primary analyses. Given that SARS-CoV-2 infection in later pregnancy carries substantial risks to women and babies, our findings support current recommendations that vaccination remains the safest way for pregnant women to protect themselves and their babies from COVID-19.
Subject(s)
COVID-19ABSTRACT
We describe SARS-CoV-2 infection and COVID-19 vaccine uptake in Scotland in a prospective cohort of all pregnant women in Scotland drawn from national databases. As of mid-October 2021, the Covid-19 in pregnancy in Scotland (COPS) cohort included linked data on a total of 139,136 pregnancies in 126,749 women. Up to September 30, 2021, a total of 22,779 COVID-19 vaccinations had been administered to 16,229 pregnant women. Vaccine coverage was substantially lower in pregnant women than in the general female population of reproductive age (23.7% of women giving birth in September 2021 were fully vaccinated compared to 74.9 % in women 18-44 years). Of the 4,274 cases of COVID-19 in pregnancy (confirmed by SARS-CoV-2 viral reverse transcriptase polymerase chain reaction) between December 2020 (the month the COVID-19 vaccination programme started in Scotland) and September 2021 inclusive, 629 women (14.7%) were admitted to hospital and 89 (2.1%) were admitted to critical care. Of the COVID-19 cases occurring in pregnant women, 81.7% (3,491/4,274; 95% CI 80.5-82.8) were in unvaccinated women. Of the COVID-19 associated hospital admissions, 93.0% (585/629; 95% CI 90.7-94.8) were in women who were unvaccinated at the time of COVID-19 diagnosis. Of the COVID-19 associated critical care admissions 98.9% (88/89; 95% CI 93.9-100) were in women who were unvaccinated at the time of COVID-19 diagnosis. The extended perinatal mortality rate for women who gave birth within 28 days of COVID-19 diagnosis was 15.9 per 1000 births (95% CI 7.8 to 31.0; background rate in 2020 6.3 per 1,000 total births [95% CI 5.7-7.1]; background rate 2019 5.7 per 1,000 total births [95% CI 5.0-6.4]). All baby deaths occurred after pregnancies in women who were unvaccinated at the time of COVID-19 diagnosis. Addressing low vaccine uptake rates in pregnant women is imperative to protect the health of women and babies.
Subject(s)
COVID-19ABSTRACT
Background: The BNT162b2 mRNA (Pfizer-BioNTech) and ChAdOx1 (Oxford-AstraZeneca) COVID-19 vaccines have demonstrated high efficacy against infection in phase 3 clinical trials and are now being used in national vaccination programmes in the UK and several other countries. There is an urgent need to study the ‘real-world’ effects of these vaccines. The aim of our study was to estimate the effectiveness of the first dose of these COVID-19 vaccines in preventing hospital admissions.Methods: We conducted a prospective cohort study using the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) database comprising of linked vaccination, primary care, Real-Time Polymerase Chain Reaction (RT-PCR) testing, hospitalisation and mortality records for 5.4 million people in Scotland (covering ~99% of population). A time-dependent Cox model and Poisson regression models were fitted to estimate effectiveness against COVID-19 related hospitalisation (defined as 1- Adjusted Hazard Ratio) following the first dose of vaccine.Findings: The first dose of the BNT162b2 vaccine was associated with a vaccine effect of 85% (95% confidence interval [CI] 76 to 91) for COVID-19 related hospitalisation at 28-34 days post-vaccination. Vaccine effect at the same time interval for the ChAdOx1 vaccine was 94% (95% CI 73 to 99). Results of combined vaccine effect for prevention of COVID-19 related hospitalisation were comparable when restricting the analysis to those aged ≥80 years (81%; 95% CI 65 to 90 at 28-34 days post-vaccination).Interpretation: A single dose of the BNT162b2 mRNA and ChAdOx1 vaccines resulted in substantial reductions in the risk of COVID-19 related hospitalisation in Scotland.Funding: UK Research and Innovation (Medical Research Council); Research and Innovation Industrial Strategy Challenge Fund; Health Data Research UK.Conflict of Interest: AS is a member of the Scottish Government Chief Medical Officer’s COVID-19Advisory Group and the New and Emerging Respiratory Virus Threats (NERVTAG) Risk Stratification Subgroup. CRS declares funding from the MRC, NIHR, CSO and New Zealand Ministry for Business, Innovation and Employment and Health Research Council during the conduct of this study. SVK is co-chair of the Scottish Government’s Expert Reference Group on COVID-19 and ethnicity, is a member of the Scientific Advisory Group on Emergencies (SAGE) subgroup on ethnicity and acknowledges funding from a NRS Senior Clinical Fellowship, MRC and CSO. All other authors report no conflicts of interest.Ethical Approval: Approvals were obtained from the National Research Ethics Service Committee, Southeast Scotland 02 (reference number: 12/SS/0201) and Public Benefit and Privacy Panel for Health and Social Care (reference number: 1920-0279).