NACI strongly advises boosters for those over 50

OTTAWA - The National Advisory Committee on Immunization has expanded its recommended eligibility for booster shots of COVID-19 vaccines in response to reports of waning protection against the virus.

NACI now strongly recommends boosters for those over 50 and said all adults over the age of 18 may receive one as well. 

The committee has also strengthened its recommendation for several other groups, and now strongly suggests boosters for people who received a full series of the Oxford-AstraZeneca or Janssen vaccine, those in or from First Nations, Inuit and Métis communities and front-line health workers.

 The new recommendation was released after an urgent request from the federal government for information on the role of COVID-19 vaccine boosters in fighting the new Omicron variant, though NACI had already been working on updated advice.

 Omicron came to light late last week, and has sparked tougher border measures around the world.

 The World Health Organization has warned the high number of mutations could signal that it is more transmissible than previous strains.

 Cases of Omicron have already cropped up across the country. Though most involve recent travel, one case, reported in Alberta, involved household transmission.

 "We know that Canadians are asking increasingly about whether they should … receive boosters, and that question is obviously of greater importance now with the new variant," Health Minister Jean-Yves Duclos said in a press conference Tuesday.

NACI recommends people get an booster of an mRNA COVID-19 vaccine six months after their second shot. 

NACI's analysis shows the vaccine offers waning protection against infection and transmission over time, and some studies show decreases in protection against serious infection, and more notably in older adults.

 "The bottom line is that if there is waning immunity over time and an additional dose or boost to your immune system helps, at least in the short term, boost your antibody levels and increase the quality of your overall immune response and the durability of the response," said chief public health officer Dr. Theresa Tam at a briefing Friday. 

There are already emerging indications that immunity is waning, according to Tam's deputy, Dr. Howard Njoo.