(Ottawa) The first-ever COVID-19 vaccine for infants and very young children is under review by Health Canada.
Posted at 11:19 a.m.
Updated at 1:06 p.m.
Moderna Canada President Patricia Gauthier said Friday the company submitted an application Thursday evening to the Canadian regulator for a vaccine to protect children aged six months to five years against SARS-CoV-2. and COVID-19. Health Canada confirmed Friday that it has begun reviewing Moderna’s application for authorization.
The pharmaceutical company says a clinical trial in 6,700 children determined the vaccine was safe and produced an antibody response similar to that seen in adults.
A single dose for children under six years old is 25 micrograms, one-quarter the dose given to adults and adolescents, and half the dose given to children six to 11 years old. Moderna proposes that its vaccine be given in two doses, four weeks apart.
The clinical trial in young children was conducted mostly during the wave of the Omicron variant, and the vaccine was found to be less effective in preventing infection in children than in previous clinical trials conducted in adults.
Vaccine effectiveness against infection in adults also dropped during the Omicron wave, although the vaccine maintained excellent protection against serious illness, hospitalization, and death.
The company said the vaccine was 51% effective at preventing symptoms in children aged six months to two years, and 37% effective against symptoms in children aged two to five years. Moderna said these results are similar to those seen in terms of efficacy against the Omicron variant for adults.
Because children rarely suffer from severe symptoms due to COVID-19, the clinical trial could not determine the impact on preventing serious illness in this cohort.
Moderna’s COVID-19 vaccine was first approved for use in adults in December 2020, then for ages 12 to 17 in August 2021, and finally for children aged six to 11 last March. .
No vaccine has yet been authorized in Canada for children under five years of age. Pfizer-BioNTech’s pediatric vaccine is licensed for children five to eleven years old, at a dose that is one-third the dose given to adolescents and adults.
Pfizer’s clinical trial for children under five found that two doses that were one-tenth the adult dose were not enough to generate a good enough antibody response. The company then expanded the clinical trial to include a third dose. The results of this trial are expected in May.
Nationally, 40% of children aged five to eleven are fully immunized, as are 84% of children and adolescents aged 12 to 17 and 88% of adults.