Babies younger than 6 months continue to face significant hospitalization rates due to COVID-19, yet there’s currently no vaccine available for this age group. This is one of the reasons the American College of Obstetricians and Gynecologists (ACOG) advocates for COVID vaccination during pregnancy.
Dr. Kevin Ault, a professor of obstetrics and gynecology, points out that studies indicate that vaccinating pregnant women helps transfer antibodies to their newborns, offering them some protection against COVID-19. However, this immunity tends to diminish around 5 months of age.
Last week, ACOG reiterated its recommendation for vaccination during pregnancy following a new study involving over 140,000 infants, which further supports the notion that maternal vaccination offers significant early-life protection against COVID. The findings of this study were published in the journal Pediatrics.
The research revealed that infants who were vaccinated in utero did not exhibit a higher rate of hospital visits for infections overall compared to those whose mothers were not vaccinated. However, those exposed to the vaccine prior to birth were about 50% less likely to require hospitalization for COVID during their first two months. By ages 3 to 5 months, the risk of hospitalization for COVID was 24% lower for these infants.
Surprisingly, the benefits of the vaccine seem to wear off once they reach 6 months. Interestingly, the study discovered that maternal vaccination did not appear to increase the risk of other infections in the infants—even contradicting some claims made by a member of a vaccine policy committee.
According to Dr. Helena Niemi Eide, the lead author of the study, although there’s often an uptick in subsequent infections following viral illnesses, their research found that the COVID vaccine during pregnancy did not lead to higher rates of other health complications in infants.
Dr. Thomas Nguyen, a pediatrician and associate professor, recalls that between 2021 and 2023, the urgency regarding mothers’ vaccination was clear, given the increased hospitalization risk faced by pregnant women infected with COVID. Consequently, medical organizations began endorsing vaccination during pregnancy.
This recent study offers a sense of validation regarding those earlier recommendations and highlights the protective effects of COVID vaccines for young infants.
Data from the CDC indicates that infants under 6 months have hospitalization rates from COVID similar to individuals aged 65 to 74, and about 20% of those infants were admitted to intensive care. Other research has also confirmed the safety and effectiveness of vaccinating during pregnancy.
The new study monitored 146,031 children born between March 2020 and December 2023, tracking their health records for two years. Notably, one in four mothers received the COVID vaccine while pregnant.
While the findings revealed no significant difference in infection-related doctor visits, they did indicate that vaccinated mothers’ infants had far fewer COVID-related hospitalizations during their initial months. Yet, by the time these infants reached 6 months, that protective effect seemed to fade.
Interestingly, babies whose mothers were vaccinated had about a 5% increased likelihood of visiting the doctor for infections, a trend that may actually stem from differing healthcare-seeking behaviors between vaccinated and unvaccinated mothers.
Niemi Eide explains that in Norway, there aren’t costs associated with medical visits or immunizations, which can often skew results in vaccine studies. By narrowing the analysis to mothers with similar health behaviors, they aimed to minimize any bias in the results.
Nguyen emphasized that the comprehensive nature of this study is reassuring, especially with such a large participant pool. He noted that tracking patients is generally easier in countries with universal healthcare systems, unlike the U.S.
The study findings stand in contrast to claims made by Robert Malone, who was appointed to a vaccine policy committee by Secretary of Health Robert F. Kennedy, Jr. A recent federal judge ruled that Malone’s role on the committee is not legally valid, raising concerns about the committee’s legitimacy.
Malone has repeatedly asserted without empirical evidence that the vaccine could lead to “immune dysregulation,” increasing infection risks. Since the current study did not find any heightened risks, these claims appear unfounded.
The research was conducted with funding from the University of Oslo and other Norwegian government agencies, without financial backing from pharmaceutical companies. This work is part of a broader research initiative investigating COVID vaccinations during pregnancy.
