Endocrinology
Partner With Us
Advertisement
From the Journals

Pregnancy COVID Protection Varies by Timing

In a multisite study of 7,677 pregnant people, COVID-19 vaccine effectiveness against urgent care visits dropped dramatically from 52% when given during pregnancy to just 6% when administered 6+ months before pregnancy.

Conexiant

A COVID-19 vaccine dose administered during pregnancy provided 52% protection against emergency department and urgent care visits for COVID-19 infections, whereas prepregnancy vaccination showed diminishing effectiveness, according to new research.

In the VISION Network study, published in Open Forum Infectious Diseases, investigators analyzed 7,677 emergency department and urgent care (ED/UC) encounters from June 2022 to August 2023 across nine states. Vaccine effectiveness dropped to 28% when administered less than 6 months prior to pregnancy and fell to 6% when given 6 or more months prior to pregnancy.

Among participants with COVID-19 infection–like disease, 12% (n = 946) of them tested positive for SARS-CoV-2. The study population predominantly consisted of women aged 25 to 34 years (57%), with 25% aged 18 to 24 years and 19% aged 35 to 45 years. White non-Hispanic participants comprised 40% of the study population, followed by Hispanic (28%) and Black non-Hispanic (8%) participants.

Vaccination patterns revealed that 39% of them were unvaccinated, while 34% received a primary series of monovalent vaccines only. Twenty-two percent received the primary series plus at least one monovalent booster, and 6% received at least one bivalent dose. Among the 443 participants who received bivalent doses, 63% of them received them during pregnancy.

The median interval between vaccination and ED/UC encounters varied significantly: 483 days for doses received 6 or more months prior to pregnancy, 267 days for doses less than 6 months prior to pregnancy, and 91 days for doses during pregnancy.

The study spanned multiple variant periods, with 68% of encounters occurring during BA.4/BA.5 predominance and 32% in the post-BA.4/5 period. Positivity rates were 14% during the BA.4/BA.5 period compared to 10% in the post-BA.4/5 period.

The research included both monovalent and bivalent COVID-19 vaccines from Moderna, Pfizer-BioNTech, and Johnson & Johnson. Study limitations included inability to account for prior infections and possible behavioral differences between vaccinated and unvaccinated groups.

The findings aligned with current U.S. Centers for Disease Control and Prevention guidelines recommending COVID-19 vaccination during pregnancy. The researchers noted that future studies should examine effectiveness against severe outcomes like hospitalization and intensive care admission.

Potential conflicts of interest can be found in the study.