The National Advisory Committee on Immunizations (NACI) has recommended against using the Oxford-AstraZeneca vaccine in people aged 65 and older, although Health Canada has authorized it to be used in adults of all ages.
The committee, which makes recommendations to governments on the use of newly approved vaccines for humans, said in documents posted Monday it does not recommend the vaccine for those 65 and older “due to limited information on [its] efficacy” in that age group.
NACI said its recommendations are based on independent advice and reflect the best current available scientific knowledge.
Health Canada authorized the vaccine on Friday as the third option to protect against COVID-19 along with those from Pfizer-BioNtech and Moderna.
Health Canada said the clinical trial results “were too limited to allow a reliable estimate of vaccine efficacy” in those aged 65 and older, but that it was comfortable approving it based on real-world evidence of its effectiveness in that age group.
One infectious disease specialist says he was taken aback by the different takes of Health Canada and NACI.
The vaccine has had good results preventing hospitalizations and deaths due to COVID-19 in the United Kingdom, says Dr. Sumon Chakrabarti, a specialist at Trillium Health Partners in Mississauga, Ont.
“We’ve seen real-world usage in the U.K., for example, and the results were really good including for people who are even 80 years of age and older. So I’m not certain what to make of this, it’s still approved for people 18 and over, and I just want to see how this plays out. But I would not hesitate to recommend it,” Chakrabarti said on CBC News Network.
Chakrabarti also said it is possible NACI may end up updating its recommendation.
‘Science in real time’
Dr. Isaac Bogoch, an infectious disease physician and member of Ontario’s COVID-19 immunization task force, said not having enough data isn’t the same as saying a vaccine isn’t effective.
He said provinces and their health authorities will ultimately have the final say about which vaccines are administered in their areas.
“This is science in real time,” Bogoch said. “You can have multiple groups look at the exact same data and come to different conclusions.”
People over age 65 are disproportionately at risk of dying or being hospitalized from COVID-19.
“We know that any vaccine that’s currently available in Canada will help now,” he said.
Alyson Kelvin, a virologist working on COVID-19 vaccine candidates at VIDO-InterVac in Saskatoon, said some countries in Europe have been hesitant about approving the vaccine for older individuals.
“I think it’s really important that if a vaccine is available one takes it and that we don’t concentrate too much on small differences in effectiveness between vaccines,” Kelvin said.
Health Canada also said Monday that “the best vaccine for a Canadian is the one they can get. All COVID-19 vaccines authorized by Health Canada will help reduce severe disease, hospitalizations and deaths from COVID-19.”
In a statement to CBC News, Health Canada noted regulators have taken different approaches to the authorization of the AstraZeneca vaccine, but most have granted unrestricted use of the vaccine for adults.
There were no safety concerns for using the vaccine in those over 65 in clinical trials or among the thousands in that age group vaccinated with it so far in other countries, Health Canada said.
More clinical trial data on AstraZeneca’s vaccine is also expected in the coming weeks from the U.S.
NACI’s recommendations also include that the Pfizer-BioNTech vaccine may be offered to those aged 12 to 15.
Health Canada said it is not uncommon for NACI to provide advice that promotes or restricts the use of some vaccines compared with others after Health Canada independently assesses if a vaccine meets the bar for safety, efficacy and manufacturing quality.