Fish said in order for a COVID-19 vaccine to work in older people, they may need a higher dosage of the vaccine, require additional booster shots every couple months or have to use it in combination with another treatment.
It is unclear who will be the first to get the vaccines, but the ones most at risk of getting infected would likely be inoculated first, according to Kerry Bowman, a clinical ethicist at the University of Toronto.
Bowman said Wednesday that health-care workers, other first responders, and the elderly could be among the first.
However, given that older people's immune systems are weaker, Bowman said it may be more effective to vaccinate everyone who may come into contact with the elderly.
"What can be done is to immediately create a protective zone around older people… Make sure that people working in long-term care facilities are immediately vaccinated so that you're protecting those older people. And then families that have older people that they're caring for or visiting regularly," Bowman said in a phone interview with CTVNews.ca.
While this could help protect the elderly, Fish said it will only be successful if the vaccine is effective.
"We have to be confident that we have a vaccine that's 100 per cent effective so you can build that wall of immunity," Fish said. "Until we know what's going on with the vaccine and how effective it is, we don’t know for sure how it will impact the elderly."
Bowman said of those vaccines that are moving towards human trials, none are using older people in their research because of the potential risks.
When Canada gets a vaccine, Bowman said the demand will be high and there will be ethical questions about who will get it first.
"If we get a vaccine, it'll be helpful but it may not be helpful for some of the most vulnerable people," Bowman said.
It is not yet known what level of immune response will be required to protect humans against COVID-19, but Fish said developing vaccines to fight the virus is still important.
"Imagine if we have one or two vaccines in the next 6 months? That will change the face of COVID-19 regardless of who takes it," Fish said.