Complete COVID-19 vaccination standards may soon change
Experts believe that a third dose is necessary for everyone.
Most of the SARS-CoV-2 vaccines available in Canada were originally designed and tested for two doses (with the exception of Johnson & Johnson).
Canada has approved the following vaccines:
- AstraZeneca Vaxzevria;
- Janssen/Johnson & Johnson;
- Moderna Spikevax;
- Novavax Nuvaxovid;
- Pfizer-BioNTech Comirnaty;
- Medicago Covifenz.
For travelers who are entering Canada, the list of recognized vaccines is longer:
- AstraZeneca/COVISHIELD (ChAdOx1-S, Vaxzevria, AZD1222);
- Bharat Biotech (Covaxin, BBV152 A, B, C);
- Janssen/Johnson & Johnson;
- Medicago Covifenz;
- Moderna (Spikevax, mRNA-1273), including for children ages 6 to 11;
- Novavax (NVX-COV2373, Nuvaxovid, Covovax);
- Pfizer-BioNTech (Comirnaty, tozinameran, BNT162b2), including for children ages 5 to 11;
- Sinopharm BIBP (BBIBP-CorV);
- Sinovac (CoronaVac, PiCoVacc).
The Chinese University of Hong Kong published earlier this year the results of a meta-analysis based on 53 studies involving more than 100 million people. It showed that three doses of the mRNA vaccine were highly effective in protecting against COVID-19 in 96% of cases, and in 95%, relieved the disease to the point that hospitalization was not needed.
The study concludes that three doses of the COVID-19 vaccine are needed to protect against infection with the Omicron strain. Not so long ago, however, it was claimed that two doses protected 92%.
"Hypothetically, if we had a vaccine that prevented long-term COVID, hospitalization and death, but didn't prevent infection, I'd call it highly successful; we'd all get colds ... but no one would get really sick, - Colin Furness, an epidemiologist at the University of Toronto, explained to reporters. — No doubt we don't have that, but three doses of the COVID-19 vaccine gets us closer to that. When we talk about full vaccination, we have to talk about three [doses]."
55.5% of Canadians aged 12 years and older have been vaccinated with three doses of the COVID-19 vaccine — an estimated 18.5 million people. Although there have been differing opinions during the pandemic about the need for a third dose of the vaccine, many provinces have officially recommended taking advantage of the opportunity to further protect themselves.
