B.C. mulls COVID-19 vaccine booster shots for immunocompromised, vulnerable seniors

British Columbia health officials say they’re planning for the potential rollout of a third vaccine “booster shot” for those most vulnerable to COVID-19.

Provincial health officer Dr. Bonnie Henry confirmed Tuesday that officials are developing plans for a rollout to immunocompromised people, as well as people living in long-term care or assisted-living facilities.

Henry said the province could unveil plans for a booster for people with weakened immune systems within the next week or two.

The timeline for people in long-term care could see shots delivered sometime around October and potentially be delivered along with the flu shot, she added.

“And we’ll be coming up with our recommendations around the best options and the best timing in the coming weeks in terms of whether everybody needs a third dose,” Henry said.

Horacio Bach, a clinical assistant professor in the division of infectious disease in UBC’s faculty of medicine, said research around the globe is demonstrating that the protection provided by vaccines fades over time.

“We know that around four, five or six months the level of protecting antibodies or neutralizing antibodies we develop as a result of the two doses of the vaccine, they start to fade,” Bach said.

Studies have shown that the average protection offered by the vaccines could fall as far as 33 per cent, he added.

He said people who have compromised immune systems, are transplant recipients, or are on certain anti-cancer drugs are particularly at risk, as their immune systems aren’t able to produce the same response from the vaccine.

Israel, the United States and Alberta, among others, have announced plans or already begun to offer third doses to certain groups people.

Henry said B.C.’s decision to increase the length of time between first and second doses of the vaccine appears to have generated a longer period of effectiveness for the immunization.

“So the data that we’re seeing right now doesn’t show that we need a booster dose yet,” she said. “It may be sometime in the new year for the average person, starting with age probably.”

Bach said one advantage of a third dose is that it can be formulated around the specific spike protein in the Delta variant, potentially providing better protection than the current vaccine, which was developed around the original COVID-19 variant.

“We need to re-engineer in our bodies the antibodies against this variant and not the previous one,” he said.

“Just a little change to make sure the antibodies and the protein work like a key and lock.”

Henry said the issue of booster shots remains under study by both the federal National Advisory Committee on Immunization, as well as B.C.’s own Immunization committee.