Delaying second COVID vaccine dose could lead to new variants: experts

In this Wednesday, June 24, 2020 file photo, a volunteer receives an injection at the Chris Hani Baragwanath hospital in Soweto, Johannesburg. (Siphiwe Sibeko/Pool via AP, File)

Experts say delaying the second dose of some COVID-19 vaccines could lead to the emergence of new variants of the virus -- but there's no sign it has happened yet.

Federal government COVID-19 task force member Dr. Andre Veillette describes the possibility as theoretical but realistic.

Quebec has responded to Canada's vaccine shortage by delaying the second dose of the two-dose vaccines -- a delay that could be more than twice the 42-day period recommended by a federal government committee.

McGill University immunology professor Jorg Fritz says the delay could lead to the emergence of variants, but he says he's more worried about variants emerging among people who get chronic symptoms of COVID-19.

While Veillette says he doesn't support Quebec's vaccine delay, he says his biggest concern around new variants is that they'll emerge as the virus continues to spread around the world.

He says it's a mistake to think that just vaccinating people in wealthy countries will make the disease go away.


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