COVID-19 booster injections are well tolerated by pregnant and breastfeeding women

A new study published September 8 in JAMA Network Open concludes that COVID-19 booster shots are well tolerated by pregnant and breastfeeding women.

The University of Washington Medicine-led study of more than 17,000 participants showed that “there are very few birth concerns after patients receive boosters,” noted lead author and Dr. Alyssa Kachikis at UW Medicine OB-GYN.

Additionally, the American College of Obstetricians and Gynecologists released a practice advisory today encouraging pregnant or breastfeeding women to receive the latest COVID-19 booster dose, which has been modified to protect against the BA.4 and BA.5 variants. This booster became available last week.

This shot is recommended for all individuals who have had 2 months since their last booster dose. And if you’re pregnant, that includes you. If you’re postpartum, that includes you.”

Dr. Linda Eckert, Obstetrics and Gynecology, University of Washington

Eckert said this study supports the importance of pregnant and breastfeeding women getting their boosters. Eckert, professor of obstetrics and gynecology at the University of Washington School of Medicine, was the study’s lead author.

“The majority of pregnant and lactating women performed really well with a booster dose of COVID-19. In fact, most participants reported that symptoms with a booster dose or a third dose were less severe than with the initial COVID-19 vaccine series,” Kachikis added.

As such, it is important that primary care providers continue to recommend both the primary vaccine series and the booster for pregnant and breastfeeding women. She added that findings from this study are now particularly relevant with the new COVID-19 booster becoming widely available this month.

Kachikes and her team collected data from a follow-up survey sent to just over 17,500 participants last October. These participants were part of an ongoing cohort survey to monitor the reaction of pregnant and lactating individuals to the initial vaccine and, in this study, the booster shots.

Just over 97 percent of the group completed the follow-up survey on reinforcers. In this cohort group, 11 percent were pregnant; Sixty percent were lactating and 27 percent were not pregnant or lactating at the time of the survey. Most (82 percent) reported injection site soreness; With 68 percent reporting other symptoms such as fatigue or fever

Importantly, when it came to a COVID-19 booster dose or a third dose, pregnant participants were significantly more likely to include a healthcare professional as an important source of information and receive a recommendation to receive a booster dose. This suggests that clinicians may play an important role in vaccine acceptance and as a source of vaccine information.

The original study, which was launched in January 2021, was designed to monitor the reaction of pregnant and lactating women to initial COVID-19 vaccinations. The average age of the group was 33, with 92 percent of the group identifying as white and 99 percent as female. When Kachikis designed this online cohort study of women, it included women who were pregnant or breastfeeding and those who were not pregnant or breastfeeding.

This follow-up study of the online group, where they receive booster doses, continues to support the finding that pregnant and lactating individuals tolerate the COVID booster vaccines well, and that they should be included in clinical trials of other related vaccines, Eckert said.

Aside from the CDC vsafe record, this is the largest US study on this issue. Canada has established a registry based on the Kachikis model.

According to the CDC, 71.3 percent of pregnant women in the United States have received at least the primary COVID-19 vaccine series before or during pregnancy. ACOG estimates that 55% have received a booster dose. This study provides important reassurance to pregnant and breastfeeding individuals who need a booster dose. Kachikis hopes that this study, along with other reassuring studies, will encourage pregnant and breastfeeding women to boost and vaccinate, if they haven’t already.

This research was supported by the National Center for the Development of Translational Sciences (UL1 TR002319) and by the National Institute of Child Health and Human Development and the Women’s Reproductive Health Research Award (2 K12HD001264-21) for study design and conduct purposes; Data collection, management, analysis and interpretation. The UW Institute for Translational Health Sciences provided management research electronic data capture support for this project and was supported by grants UL1 TR002319, KL2 TR002317, and TL1 TR002318 from NCATS.

The content of the study report is the sole responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.


Journal reference:

Kachikis, A.; et al. (2022) Analysis of vaccine interactions after COVID-19 vaccine booster doses among pregnant and lactating women. JAMA Network is open.