By Ismail Shakil
(Reuters) -Canada on Thursday authorized Moderna Inc's bivalent COVID-19 shots for adults, adding the first Omicron-adapted vaccine to its arsenal just as falling temperatures are poised to force people indoors where the risk of infection is higher.
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.
Moderna's so-called bivalent vaccine targets the original 2019 virus and the BA.1 version of Omicron, which caused a sudden, exponential rise of infections in Canada last winter.
"As winter comes and as people get pushed back indoors, there is a real risk of another serious wave of COVID," Prime Minister Justin Trudeau told reporters in Winnipeg, Manitoba.
"If we are able to hit that 80-90% of Canadians up to date on their vaccinations, we'll have a much better winter with much less need for the kinds of restrictions and rules that were so problematic for everyone over the past years," he said.
Health authorities in Europe and North America have also recommended bivalent vaccines, which are also made by Pfizer Inc and BioNTech.
Regulator Health Canada said in a statement that Moderna's bivalent Spikevax booster was safe and effective, while also generating a "good immune response" against the Omicron BA.4 and BA.5 sub-variants.
Canada has secured 12 million doses of the new vaccine booster, and Moderna will start delivering them from Friday.
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.
Chief medical adviser to the federal health ministry, Supriya Sharma, said at a briefing that a bivalent vaccine made by Pfizer and BioNTech was under review, and Health Canada was expecting vaccine makers to also submit applications for boosters targeting the BA.4 and BA.5 sub-variants.
By mid-August, more than 90% of Canadians over 12 had taken the primary series of a COVID vaccine, while about 57% in the same age group had taken a booster, according to official data.
Staying up-to-date on booster shots would also help to significantly reduce hospitalizations linked to COVID by winter, said Health Minister Jean-Yves Duclos.
"Vaccine protection is like a phone battery: it needs to be recharged from time to time," he said.
(Reporting by Ismail Shakil in Ottawa; Editing by Chizu Nomiyama, Bernadette Baum and David Gregorio)