What a 4th COVID shot can do for you — and what it can’t – CBC

Less than half of Canadians have gotten a 3rd dose as BA.5 variant spreads rapidly

Jul 16, 2022

Fourth doses of COVID-19 vaccines are rolling out to more Canadians as eligibility opens up across the country, but research suggests there are limitations to the impact they can have on the highly contagious BA.5 Omicron subvariant fuelling Canada’s first summer surge.

After growing pressure from health-care workers and the general public for access to additional shots, some provincial governments have expanded eligibility from just immunocompromised and older Canadians to anyone over the age of 18.

But the move contradicts the National Advisory Committee on Immunization (NACI)’s recent recommendations that a second booster should only be given now to those at highest risk of severe COVID-19, while younger Canadians could wait until the fall.

Data shows that while a third dose offers a significant increase in protection against infection, hospitalization and death — a fourth dose gives only marginal benefit against severe COVID-19 for most, including short-lived protection against infection, even in vulnerable groups.

Read more: https://www.cbc.ca/news/health/fourth-dose-covid-vaccine-canada-omicron-ba5-1.6521937