New COVID vaccine offers ‘boosted protection’ against new variants: doctors – National

Public health officials say the number of COVID-19 infections is rising again — just in time for respiratory virus season in the fall and winter, when respiratory syncytial virus and the flu also come into play.

Health Canada recently authorized an updated COVID-19 mRNA vaccine, manufactured by Moderna, that targets the XBB.1.5 Omicron subvariant currently circulating. The federal government sends the new vaccine to provinces and territories, which are responsible for rolling it out to the public.

“I think the timing is right,” said Dr. Jeffrey Pernica, head of the division of infectious diseases at McMaster University in Hamilton.

“The incidence of COVID-19 has started to rise. »

But it’s clear that many Canadians are tired of getting vaccinated against COVID-19: according to the Public Health Agency of Canada, only 22 per cent of people aged five and older have received the bivalent booster dose. , which offered protection against the Omicron variant in addition to the original strain of the coronavirus.

So why should Canadians roll up their sleeves again? Here’s what doctors and scientists say you need to know.

Moderna’s Spikevax mRNA COVID-19 vaccine, updated to target Omicron’s XBB.1.5 subvariant, is approved for people aged six months and older.

But Health Canada is also reviewing updated versions of two other COVID-19 vaccines.

One of them is Pfizer-BioNTech’s Comirnaty vaccine, designed to target XBB.1.5 and approved by the FDA in the United States earlier this month.

The other is a non-mRNA option. Novavax has updated its protein subunit vaccine to also target XBB.1.5. The company is still awaiting FDA approval in the United States.

The updated vaccines specifically target the coronavirus subvariants currently circulating, which are “quite different from the original recipe,” said Angela Rasmussen, a virologist with the Vaccine and Infectious Disease Organization at the University of Saskatchewan.

The latest boosters were bivalent formulas targeting both the original coronavirus strain and BA.1 or BA.5, which are subvariants of the Omicron variant.

But the XBB subvariants, which are the main strains currently appearing in Canada, are derivatives of Omicron BA.2 — and that subvariant was not targeted by the previous bivalent booster, Rasmussen said.

So even if you get the bivalent booster, it’s still worth targeting the new shot at XBB.1.5, she said.

“It’s going to give people two things. This will provide them with a temporary boost in protection against infection,” Rasmussen said. “These will be antibodies that the booster will produce that will be more specific than the ones they already have from the vaccines they have received so far.”

More importantly, the vaccine will provide “additional longer-term protection against the development of severe disease,” she said.

Dr. Lawrence Loh, executive director of the College of Family Physicians of Canada, agrees.

“The fact is that the variants have changed. So it’s best if he’s aware of what’s going on… right now,” said Loh, who is also a family doctor and former medical officer of health for Peel Region, west of Toronto.

It’s true that many people may have some hybrid immunity (double protection from a combination of vaccination and infection) against COVID-19, doctors say.

But immunity wanes over time – so if six months or more have pa*sed since your last infection or booster, then getting the updated vaccine is a good move to restore your protection this fall and winter, said Dr. Theresa Tam, public sector manager. Canada’s public health officer, during a press conference on September 12.

Additionally, the effect of infection on boosting immunity varies from person to person, Rasmussen said.

“If you have been infected in the past year, you have likely been infected with one of the XBB subvariants. But for some people it will act as a booster (injection), but for others it may not. And you don’t know which one you’re going to be,” she said.

“Getting this booster ensures that you will have this extra protection.”

In addition to the COVID-19 vaccine, flu vaccines will be available across the country this fall.

Like the updated COVID vaccine, the flu vaccine is formulated to match as closely as possible the strains of the virus that are expected to be circulating. Although some people can still get the flu if they are vaccinated, it still protects against serious illness, doctors say.

It is safe to receive both the COVID-19 booster and the flu vaccine, the Public Health Agency of Canada said.

Receiving both vaccines will not affect their immunological effectiveness, Rasmussen said, noting that health care providers can administer one shot in each arm simply to minimize pain.

Health officials hope the convenience of receiving both vaccines at the same time will increase uptake of both vaccines.

“I think what we kind of forget when we think about why people aren’t getting vaccinated is the logistics,” said Dr. Kumanan Wilson, scientific director at the Bruyère Research Institute in Ottawa and immunization researcher. “Make access as easy as possible.”

Health care professionals are hoping to avoid the “tripledemia” that overwhelmed hospitals and doctor’s offices last fall.

However, there is currently no RSV vaccine for children, who were hit hard by the virus last year. A new RSV vaccine called Arexvy, made by GSK, is available this year for adults 60 and older. But it’s not yet clear how widely available this will be.

The exact timing varies by province and territory, but the flu vaccine and updated COVID-19 vaccine should be available in most of the country sometime in October.

Some provinces and territories, including Ontario, Saskatchewan and the Northwest Territories, are starting by vaccinating high-risk populations, including seniors living in long-term care facilities and retirement homes, before make COVID and flu vaccines available to the general public.

Doctors and scientists agree that it is especially critical that vulnerable populations like these be prioritized for vaccination.