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UPDATE: This story has been edited with calculations reflecting a shift from first doses to second doses in the future.

TORONTO – More than 60% of eligible Canadians have been vaccinated with their first doses of COVID-19 vaccine in Canada. But the rate at which the second doses are given is still far behind that of the first dose.

The federal government has previously declared that anyone eligible and willing to receive the vaccine can be fully immunized by September, but over the past seven days, Canada has vaccinated an average of almost 1% of Canadians with their first dose. and 0.11 percent of Canadians on their second dose.

If that vaccination rate continues through the summer, the country would have 20 percent of its eligible population – those 12 and older – fully vaccinated by early October.

Canada currently administers an average of 356,304 vaccines per day. About 90% (319,531) of these are first doses, of which 10% (36,773) are second doses. Assuming the overall immunization rate holds, how long would it take to transition to second doses to see a significant proportion of Canadians fully immunized by the end of the summer?

Suppose Canada maintains its current rate until 90% of Canadians receive a first dose, then switches to focusing each dose on a second vaccination. The country is expected to reach 90% with a single vaccine by June 26 and 8.5% of them would be fully vaccinated by that day. Administering our current number of vaccines as a second dose would increase the second dose rate to 1.07% of eligible Canadians per day. This would see the country strike:

• 20% fully vaccinated by July 7
• 50% by August 4
• 80% by September 1
• 90% by September 11

These calculations assume that the number of vaccines given each day remains the same – if the overall rates change, those projections also change.

The graph below shows projections based on our current rates and will be updated daily as rates change. Graphic projections don’t account for future rate changes, and the graph does not recalculate the second dose projections even if the first dose projection has reached 100%. But it is useful for an updated answer to the question “If each dose stays at your current rate, when are we going to meet that goal?” “

Currently, for second doses, this response is further away than it actually will be – but as the rate of second doses increases, this graph will reflect this increased rate.

The gap between the first and second dose rate was a decision made individually by the provinces, but after a recommendation from the National Advisory Committee on Immunization (NACI) to extend the time between the first and second dose from four to four. 16 weeks.

“The idea was to partially vaccinate more people to reduce the likelihood of them transmitting the virus and getting sick from it,” Dr. Brenda Coleman, infectious disease epidemiologist at Sinai Health in Ontario, told CTVNews.ca , adding that after a dose of vaccine, the effectiveness is about 80%.

To date, Canada has received more than 25.39 million doses of COVID-19 vaccine from manufacturers and, according to Brig.-Gen. Krista Brodie, confirmed more than 40 million doses at the end of June.

Dr Coleman says that with the increased doses Canada receives, up to 75 percent of adults can be fully immunized by the end of the summer.

“The number of doses scheduled by the end of August will likely be mostly used to give people a second injection,” Coleman said. “If so, 70-75% of adults should get both vaccines by the end of the summer if we can get them in people’s arms.”

With a large proportion of adults fully vaccinated, Coleman says this would significantly reduce the transmission rate of a herd immunity approach, but a full vaccination of 80 to 90 percent would help end the pandemic in Canada.

While the first doses are well advanced for adults, immunizations are only just beginning in young Canadians.

Earlier this month, Health Canada approved the Pfizer-BioNTech vaccine for children 12 years of age or older, citing clinical trials that showed the vaccine to be 100% effective in people aged 12 to 15.

“One of the reasons 12 to 17 year olds go to school is because they are in school, visiting friends and doing these kinds of things. So if we can get them vaccinated, we’ll reduce transmission, ”Coleman said.

If the wait time between the first and second dose is shortened, Coleman suggests prioritizing people with high transmission, including those 12 to 17 years old.

“We have to prioritize the people who are there and see a lot of people. So the people who work in the factories, the people in the health sector, the teachers, ”she said. “One of the other groups will be our kids going back to school… they can’t help but be in small rooms with lots of people around. So while they tend not to get as sick as the elderly, we don’t know what to expect from these mutations.

## Correction:

The article previously included a section on the full vaccination rate for the general Canadian population based only on current second dose rates. It has been deleted because the story has been edited to better reflect a reality where second doses will increase after the first doses are given.