Muhammad Ali Bukhari, CNMNG News

Toronto, March 23: The top Canadian scientists did not support the delay between the two doses of the corona vaccines, which have been used for 4 months in the elderly. Their argument is that there is no specific study, not even a prerequisite for that population.

In early March, the National Advisory Committee on Immunization, in short, NACI issued guidance, which allows interval between doses of the Pfizer-BioNTech, Moderna, and AstraZeneca vaccines extended up to four months while still being effective.

As a result, several Canadian provinces, particularly Ontario, Manitoba and British Columbia, have followed that policy to include another age group in the immunization program. This means that the time limit approved by the vaccine manufacturer for the second dose has been significantly delayed.

So, yesterday (Monday), Canada’s chief science adviser, Mona Nemer said that in the case of the elderly, there is a risk of adverse effects due to this prolonged delay between the two doses. She said, “I’m not aware of data showing that there is efficacy beyond two months of the first dose. In the past few weeks, we’ve seen different studies come out showing that the response to the first dose of the vaccine in the people who are elderly, in the people who are immuno-compromised is actually not that good and it wanes quite rapidly.”

A preliminary study in the UK last week found that in 95 percent of cancer patients, especially the elderly, taking a second dose within three weeks of the first dose of Pfizer quickly develops physical antibodies. And this result has occurred in only 43 percent of patients at five-week intervals.

However, the delay between these two doses was initially set by Health Canada at 21 days for Pfizer-BioeNTech vaccine, 28 days for Moderna and 12 weeks or three months for Astra-Zeneca.

But the National Advisory Committee on Immunization or NACI says the break has been prolonged by the kind of high-capacity resistance to scientific research and “real-world efficacy.” And with the supply of vaccines available at the time, this first dose has been recommended instead of waiting for the second dose to bring more people under the vaccination.

For such, Canada’s chief science adviser, Mona Nemer said the latest research data is open to both Health Canada and NACI, which means the new recommendation, is coming as usual. She said they are both following it and implementing it for model recommendation purposes. Because, “As data emerges about what it takes to protect [seniors and immune-compromised people], we need to be reviewing what we’re doing.”

Good to know, Canada is hopeful about 2 million doses of Pfizer and Moderna vaccines will arrive this week, as well as 1.5 million doses of Astra-Zeneca at the end of this month.