Hamilton researchers propose study of new high-dose flu shot
Hamilton researchers want to study the new high-dose flu shot that the province plans to give seniors next year.
Premier Kathleen Wynne announced in Hamilton Tuesday that seniors will get a different influenza vaccine from the rest of Ontarians starting next flu season.
“In healthy adults, people respond relatively well to the vaccine,” said Dr. Mark Loeb, division director of infectious diseases at McMaster University.
“In older adults, it becomes less effective because of waning of the immune system. They can’t produce a rigorous response to the vaccine and that renders them at risk.”
It’s significant considering flu causes about 12,200 hospitalizations and 3,500 deaths in Canada each year, and those most at risk are the very young and the very old.
“The older you get, the more at risk you are of complications,” said Loeb. “It’s very serious.”
There are two flu shots that have been specifically developed for seniors.
One is the vaccine the province has chosen, which contains higher doses of the protein that leads to an antibody response.
The other is an adjuvant vaccine, which means it stimulates the immune system to enhance the response.
Both have been shown in studies to offer better protection to seniors than the standard flu shot.
In the case of the high-dose immunization, it reduces flu in seniors by about 25 per cent more than the regular vaccine.
“What’s interesting to me is comparing those vaccines,” said Loeb. “We don’t really know which one would be most protective.”
Determining which vaccine works best is the goal of Hamilton researchers, led by Loeb.
They already have a proposal before Public Health Ontario to study the two vaccines head-to-head in a randomized controlled trial. The research would provide the missing piece of the puzzle.
“There have not been comparative trials,” said Loeb. “This is such an important question. A lot of public health people ask themselves this question.”
Loeb has funding from the Canadian Institutes of Health Research for the study, but would need additional support from the Ministry of Health.
The plan is to do the research at Ontario long-term care centres.
“Those are the residents who are the most frail and the most vulnerable and it’s really important to protect them,” said Loeb. “It’s best to do this over several seasons, but we could potentially find an answer over one season because there are so many nursing home beds.”