Longer wait between doses of Pfizer COVID-19 vaccine for Canadian kids recommended
TORONTO -- Canada’s National Advisory Committee on Immunization is recommending an eight-week interval between doses for the newly approved Pfizer-BioNTech COVID-19 vaccine for children between five and 11 years of age, rather than the three weeks approved by Health Canada. It will ultimately be up to provinces to decide which interval is best.
On Friday, Health Canada authorized the Pfizer vaccine for children, making it the first in the country to receive regulatory approval for that age group. A total of 2.9 million doses are expected arrive by the end of next week.
Although Health Canada, and Pfizer, say the vaccine can be offered three-weeks apart, the National Advisory Committee on Immunization (NACI) has recommended an eight-week interval between doses.
NACI notes that while there is no direct evidence on an optimal interval for children, it cited evidence in adults that a longer gap may improve immune response.
"We see that NACI has made a different recommendation based on … their own analysis of the data," Fabien Paquette, vaccines lead for Pfizer Canada, told CTV News.
"So at the end of the day, either from a NACI standpoint or for any … provincial jurisdictions, it remains their decisions to apply the immunization programs the way they feel is most appropriate for their population."
Paquette said through discussions with federal authorities, particularly the U.S. Food and Drug Administration (FDA), a three-week interval was agreed upon for Pfizer's clinical programs, as was the case for adolescents and adults.
Asked whether it would make any difference to the effectiveness of the vaccine, he said that data isn't available.
"What we have in our own data sets is really an interval of three weeks. A longer interval has not been studied with this age group," he said.
"Now, we can make some assumptions based on what we've seen in the … adult groups, and that's probably the way the analysis has been done by the public health authorities. But related to what we see right now, the data available are really with an interval of three weeks."
Paquette said it's too early to say whether pediatric vaccines for COVID-19 will be offered annually, but that more data will be gathered to ensure "the best decisions will be taken in that regard."
Paquette also called the Health Canada authorization a "day that many parents across the country have been eager to wait for" and a likely "game-changer" to further protect Canadians against COVID-19.
He said Pfizer submitted a "significant" amount of data to Health Canada, namely for the Phase 2 and 3 trials, with more than 4,600 children participating, resulting in 91 per cent effectiveness and few side effects.
He said there were no cases reported of myocarditis, a side effect noted with mRNA vaccines resulting in inflammation of the heart muscle, during the clinical trials. But he added that Pfizer is taking this seriously and will pay attention to any reporting that comes out as the vaccines are used in Canada and around the world.
Asked about parents on the fence about vaccinating their child, Paquette said it is "totally understandable."
"If you have children, five to 12 years of age, you want the best for them, and the best for them from what we see right now with the science available is clearly to present them with a vaccine that has been officially authorized by Health Canada. And I would say talk to your health-care providers," he said.
As far as vaccine mandates for children, Paquette said that is not for a pharmaceutical company to answer, but rather public health authorities.