Researchers have found that while the benefits of COVID-19 vaccination during pregnancy have waned over time, they remain substantial for public health, publishing their findings in JAMA Network Open.1
Pregnancy was removed as an indication for COVID-19 vaccination in May 2025 by the US Department of Health and Human Services. However, data has highlighted the transfer of maternal antibodies to the infant when vaccination is provided during pregnancy, offering direct protection to newborns during a period where the risk of severe infection is greater.
Key takeaways:
- Study findings published in JAMA Network Open show that COVID-19 vaccination during pregnancy continues to provide meaningful protection for both mothers and infants.
- Maternal antibodies transferred during pregnancy help shield newborns under 6 months, who face a higher risk of severe COVID-19 infection.
- Modeling data from 2024 to 2025 estimated over 1,200 infant and 200 maternal hospitalizations could be prevented with 50% vaccination coverage.
- Effectiveness has declined over time, but researchers stress vaccination still significantly reduces COVID-19 hospitalizations in this population.
- Experts urge reconsideration of vaccine eligibility during pregnancy and highlight the broader importance of maternal immunization for COVID-19, influenza, and RSV.
“Infants younger than 6 months are not eligible for COVID-19 vaccination, and their risk of severe COVID-19 is much higher than other pediatric age groups, often similar to those aged 65 to 74 years in the current epidemiologic era,” wrote investigators.
Assessing avoidable COVID-19 hospitalizations
The study was conducted to identify the number of preventable COVID-19 hospitalizations in pregnant patients and their young offspring through vaccination during pregnancy. COVID-19 hospitalizations between January 2024 and May 2025 were identified through publicly available US surveillance data. Patients were aged 18 to 49 years.
Most COVID-19 vaccines during pregnancy were administered during the second or third trimester. The impact of this regimen on health outcomes was assessed using recent vaccine effectiveness estimates, such as an estimated 35% decline in COVID-19 hospitalization risk in infants aged under 6 months and 33% effectiveness across 4 months in adults.
There were 7148 estimated cases of COVID-19 hospitalization in young infants among a population of 1.83 million between January 2025 and May 2025. Among pregnant patients, 3106 COVID-19 hospitalizations among a population of 3 million were estimated.
Hospitalization estimates and vaccine impact
COVID-19 hospitalization was estimated to be averted in 1251 infants when vaccine coverage was 50%, vs 2502 when coverage was 100%. In pregnant patients, 228 severe COVID-19 cases were averted at 50% coverage vs 456 at 100%. When vaccine coverage was low:
- 375 hospitalizations were averted in infants
- 68 severe cases were averted in pregnant patients
These results indicated significant benefits from COVID-19 vaccination during pregnancy. While these benefits have waned over time, investigators concluded the data highlight a need to reconsider removing vaccine eligibility during pregnancy.
“Continued studies on the COVID-19 risk and vaccine effectiveness in this population are important,” wrote investigators.