TORONTO – A new study says the COVID-19 vaccine protects pregnant women from getting severely ill or giving birth prematurely.
Researchers led by the University of British Columbia analyzed data on almost 20,000 pregnant people infected with COVID between April 5, 2021 and Dec. 31, 2022.
That time period covered infections with both Delta and Omicron variants in eight provinces and one territory.
The JAMA study found that vaccinated pregnant women were about 60 per cent less likely to be hospitalized and 90 per cent less likely to need intensive care compared to those who were unvaccinated when they got the virus.
The authors say the risk of premature birth was 20 per cent lower during the Delta wave and 36 per cent lower during the Omicron wave among women who were vaccinated.
They emphasize there is no bad time to be vaccinated, as results suggest that COVID vaccination during pregnancy may reduce rates of premature birth even more than getting the shot before becoming pregnant.
The researchers are part of the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) program, which is led by UBC.
The study, published Monday, captured data from pregnancies in British Columbia, Alberta, Manitoba, Ontario, Quebec, New Brunswick, Prince Edward Island, Nova Scotia and Yukon.
This report by The Canadian Press was first published Dec. 15, 2025.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
