Vaccination against COVID-19 offers significant protection for both expectant mothers and their infants. A comprehensive study led by researchers at the University of British Columbia (UBC) and published in JAMA reveals that pregnant individuals who received the COVID-19 vaccine were substantially less likely to face severe health issues or premature delivery.
This pivotal research examined data from nearly 20,000 pregnancies across Canada, demonstrating a strong correlation between vaccination and reduced risks of hospitalization, intensive care unit (ICU) admissions, and preterm births. Remarkably, these protective effects remained consistent even as the virus transitioned from the Delta variant to Omicron and its subsequent subvariants, which continue to circulate today.
"Our research provides robust, population-level evidence indicating that COVID-19 vaccination is beneficial for both pregnant individuals and their babies, mitigating serious complications," stated Dr. Deborah Money, a professor of obstetrics and gynecology at UBC and the study's senior author. "Even with the virus's evolution, vaccination has consistently delivered significant advantages for mothers and their children."
Conducted by the national CANCOVID-Preg surveillance network, this study represents one of the largest datasets globally concerning COVID-19's impact on pregnancy. The findings revealed that vaccinated individuals were approximately 60% less likely to be hospitalized and 90% less likely to need intensive care compared to those who were unvaccinated at the time of infection. Vaccination also correlated with a notable decrease in premature births—by 20% during the Delta wave and 36% during the Omicron wave.
Interestingly, the analysis indicated that those who were vaccinated during their pregnancy experienced even lower rates of preterm birth and stillbirth compared to those vaccinated prior to conception.
"There is no wrong time to get vaccinated—whether you're currently expecting or planning to become pregnant," emphasized Dr. Elisabeth McClymont, the study's lead author and an assistant professor in UBC's obstetrics and gynecology department. "However, our findings suggest that receiving the vaccine while pregnant may offer additional benefits."
These findings are particularly relevant as vaccine guidelines for pregnant individuals are evolving in various regions. In the United States, the Advisory Committee on Immunization Practices (ACIP) recently chose not to include a specific recommendation for COVID-19 vaccination during pregnancy in its updated adult immunization schedule. In contrast, public health authorities in Canada and the World Health Organization continue to advocate for COVID-19 vaccination for pregnant individuals.
The researchers believe that their findings provide crucial evidence to inform ongoing policy debates. "The evidence overwhelmingly supports the conclusion that COVID-19 vaccination is both safe and effective during pregnancy," remarked Dr. Money. "This latest research offers vital information for expectant mothers and their healthcare providers, reinforcing public health recommendations advocating for vaccination during pregnancy."
This nationwide analysis encompassed data from nine provinces and one territory in Canada. The team utilized population-based health data to assess outcomes from nearly 20,000 pregnancies affected by SARS-CoV-2 between April 2021 and December 2022.
Even after accounting for factors such as age, body mass index, and pre-existing conditions like hypertension or diabetes, the study found that vaccination was linked to significantly lower hospitalization risks.
Beyond its implications for COVID-19, this research highlights the necessity of including pregnant individuals in vaccine research and planning for future respiratory virus outbreaks. "Pregnancy is a distinct period of vulnerability but also presents a unique opportunity for preventive measures," Dr. McClymont noted. "This study reaffirms how vaccination can profoundly impact maternal and infant health."
This important study received funding from the Public Health Agency of Canada through the COVID-19 Immunity Task Force, as well as the Canadian Institutes of Health Research and the BC Women's Health Foundation.
