More and more health experts believe that provinces should vaccinate their populations more massively against COVID-19, rather than reserving currently available doses for the second scheduled injection.
A good idea, as long as Canada is able to guarantee a supply of enough vaccine within the 21-28 days scheduled to deliver the second dose, as the Pfizer / BioNTech and Moderna protocols provide, believes. retired virologist Jacques Lapierre.
“People need to be vaccinated fairly quickly for the second dose,” he recalls. If they are given the first dose – that’s going to protect them at around 40% or 50% – and they need the second to get to [une efficacité de] 90% or 95% is a choice to make, but make sure you have the second dose supplied. ”
Projections by researchers at the University of Toronto, unveiled last week by the Globe and Mail, demonstrate that administering the vast majority of doses available now – rather than keeping half for the second injection – would significantly curb COVID-19 contamination.
According to experts from the United States Medicines Agency (FDA), the Pfizer / BioNTech vaccine is very effective in preventing severe forms of COVID-19 after two doses, but also in preventing COVID-19 after the first dose.
In the case of Moderna’s vaccine, it was shown to be 50.8% effective within two weeks of the first injection and 92.1% after the first 14 days.
Although the second injection is absolutely necessary to ensure long-term immunity, some experts believe that a possible delay in the supply would not render the second dose to zero.
“It won’t cancel out, but you’re going to have limited protection then. The expected effect of the vaccine is really by respecting the vaccination protocol that it is obtained, insists Jacques Lapierre, however. When we vaccinate, we must seek the maximum protection that we are able to have with the vaccine. “
Major General Dany Fortin, who is leading the logistics of the federal vaccination campaign, said last week that provinces can expect a reliable and steady supply from suppliers over the coming weeks.
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