Safety of and Adverse Reactions to the COVID-19 Vaccine Among Pregnant and Breastfeeding Women

TL;DR

This study found that the COVID-19 vaccine is generally safe for pregnant and breastfeeding women, with most side effects being mild.

Contribution

The study provides new evidence on vaccine safety in pregnant and breastfeeding women in Vietnam.

Findings

Localized pain at the injection site was the most common adverse reaction (26.2%).

Most adverse reactions were mild, with severe events like coma or premature birth being rare.

Factors like age, occupation, and allergy history were associated with adverse reactions.

Abstract

Objectives: This study aimed to evaluate the incidence of adverse reactions to the COVID-19 vaccine among pregnant and breastfeeding women and identify associated demographic and clinical factors. Methods: A cross-sectional study was conducted at a hospital in Hanoi, Vietnam, from November 2021 to March 2022. A total of 1204 participants, including 991 pregnant women beyond 13 weeks of gestation and 213 breastfeeding women, were recruited through convenience sampling. Data were collected using a self-administered questionnaire designed to capture demographic information and adverse reactions occurring within seven to 28 days post-vaccination. Statistical analyses, including chi-square tests, Fisher’s exact tests, and logistic regression, were performed using Stata 16.0, with the significance set at p < 0.05. Results: The most common adverse reactions were localized pain at the injection site (26.2%), dizziness and fatigue (19.2%), and fever below 39 °C (29.1%). Severe adverse reactions, such as a tight throat, coma, and premature birth, were rare. A multivariate analysis identified the significant factors associated with the adverse reactions, including age (aOR = 2.04 for participants aged 36–40 years), occupation (lower odds for farmers and business professionals), urban residency (aOR = 0.64), and a history of allergies (aOR = 1.59). Education level, number of children, and gestational age were not significantly associated with adverse events. Conclusions: The findings support the safety of the COVID-19 vaccine in pregnant and breastfeeding women, with most of the adverse reactions being mild and self-limiting.