Canada authorised Moderna's bivalent COVID-19 shots for adults on Thursday (Sep 1), in the country's first approval of a vaccine adapted for the highly contagious Omicron variant of the coronavirus.
COVID vaccines were originally developed to target the coronavirus strain first detected in China in 2019. Several new variants have since been detected, with Omicron considered one of the most contagious.
The new so-called bivalent shots target two variants of the coronavirus. Moderna's bivalent vaccine approved by Health Canada targets BA.1 version of Omicron and the original 2019 virus.
Moderna's bivalent Spikevax booster was found to be safe and effective in Health Canada's review, the health authority said in a statement.
The vaccine dose was also found to generate a "good immune response" against the Omicron BA.4 and BA.5 sub-variants, Health Canada added.
Ahead of an anticipated rise in COVID-19 and other seasonal respiratory illnesses with the arrival of colder winter weather, health authorities in Europe and North America have started to recommend bivalent vaccines, which are also made by Pfizer and BioNTech.
The United States authorized boosters from Pfizer-BioNTech and Moderna that were retooled to target Omicron BA.4 and BA.5 subvariants for everyone aged 12 and older on Wednesday. The European Union's drug regulator also backed two bivalent vaccine boosters for the same age group on Thursday.
Health Canada was reviewing a bivalent vaccine made by Pfizer and BioNTech, chief medical adviser to the federal health ministry, Supriya Sharma, said at a briefing.
"To ensure we have as many options as possible for dealing with current and future variants, we have reached out to both Pfizer-BioNTech and Moderna to request that they file submissions for vaccines specifically targeting the BA.4 and BA.5 subvariants," Sharma said.