WATCH | When is the best time to get a 4th COVID-19 vaccine? When should you get your 4th COVID-19 vaccine? Duration 4:29 Infectious diseases specialist Dr. Zain Chagla explains who should get a second COVID-19 vaccine booster, and when. A new Canadian study published in the BMJ analyzed the effectiveness of a fourth dose on Ontario long-term care residents. "That fourth dose is maybe incremental, maybe just a modest benefit, but the third dose I think it's very clear.

Source: CBC News July 17, 2022 11:51 UTC