Quebec’s advice on booster shots ‘doesn't make a whole lot of sense,’ public health experts say

Some public health experts are questioning the advice of Quebec’s health ministry, which recommends double-vaccinated people who have just recovered from COVID-19 should get a third dose of the vaccine “as soon as possible.”

In the span of just a couple of months, the province's recommended waiting time between contracting COVID-19 and getting a booster shot went from eight weeks to as soon as your symptoms end.

So, what changed? According to the province, the new guidance is a result of the lack of testing capacity in recent weeks — without the ability to know for sure who had COVID-19, the province wants to err on the side of giving more boosters to more people, even if this goes against the advice of its own medical advisers.

The new advice comes as thousands of new cases have been reported daily through much of December into January during the height of the Omicron surge in the province, but it's puzzling some experts.

“The idea of getting a booster after you had an infection, that's a true COVID infection, doesn't make a whole lot of sense,” said Jamie Scott, a molecular immunologist and professor emeritus at Simon Fraser University.

Scott, whose research focuses on antibody responses to vaccination and natural infection, said someone infected with the novel coronavirus has a “pretty darn huge immune response” and the antibodies in that person would even be far greater than that provided from a third dose based on the scientific literature she has reviewed.

“The other issue is that the booster isn't going to be effective, partly because the antigen made by the vaccine gets cleared. And the other part of it is that since you had your infection, you're developing what are called memory cells," she explained.

"So you’re expanding that [cell] population that was initiated by the vaccine, [it] got expanded by your infection, and that expansion is still happening. And it takes a couple of months for that expansion for those cells to be fully developed.”

Previously, the government-run online booking portal for vaccine appointments, Clic Santé, posted a message on their website for people scheduling their booster shot that said: “If you have had COVID-19, schedule your appointment eight weeks after the beginning of your symptoms or a positive COVID-19 test.”

Now, the website only advises that three months must have passed between someone’s second dose and the third dose, without any guidance on when to book an appointment following a recent infection.

WAITING 2-3 MONTHS RECOMMENDED BY INSPQ, CIQ

Dr. Donald Vinh, an infectious disease specialist at the McGill University Health Centre (MUHC), said the province should be clear about its advice to the public and provide people with consistent health communications during the pandemic.

Both Vinh and Scott agree that booster shots are crucial and key to bolstering the body's defences while the coronavirus is still circulating widely in the community, but say it doesn’t make much sense to rush out and get a booster after symptoms have cleared up from a confirmed COVID-19 infection.

Those people, the experts say, can wait two to three months for a third jab as long as they've already had their two doses. 

“If you've been infected, whether or not you were hospitalized, the benefit of the third dose at that point has sort of passed. The horse is already out of the barn,” Vinh said.

"So for a directive, to say 'If you had a recent infection, once your symptoms are over go get your booster dose,' I think it lacks a little bit of the intellectual thought process here."

Another question is which variant infected which people. Early data from South Africa, one of the locations where Omicron first spread, suggest that antibodies from a previous Delta variant infection will not protect you from Omicron — now the predominant variant circulating in Quebec.

Vinh said in an ideal world, everyone would know which variant they were infected with. On the other hand, he said that based on premilinary data it doesn't appear likely that you can be re-infected with Omicron twice, but more research is needed on this front. 

“So at this point, there's no obvious reason, immunologically or clinically, to say, ‘Well, you know what, you've had two doses, you've had an infection, then go ahead and get a third dose right now," he maintained.

INSPQ, CIQ RECOMMEND A DELAY

The experts who spoke to CTV News aren’t the only ones who agree that waiting two to three months for a booster shot post-infection is sound advice.

The province’s own public health institute, the INSPQ, and Quebec’s immunization expert panel, the Comité d’immunisation du Québec (CIQ), also recommend delaying the shot for that amount of time. 

CTV News asked Quebec’s Ministry of Health and Social Services to explain the shift in guidance on booster shots.

A spokesperson said in a statement that the new guidelines are in part due to the limited testing available to the public. As of right now, PCR testing in screening centres is prioritized for health-care workers, first responders, people who are homeless, and other people in high-risk settings.

During the second half of December, testing sites were overwhelmed almost daily with hundreds of people anxious to get confirmation that they had been infected with the coronavirus.

That means that people often can't be sure if they did really have COVID-19 recently.

“Due to the tightening of access to PCR testing and the limited availability of rapid tests, it is becoming difficult to distinguish between those who have recently had COVID-19 and those who have not," the health ministry's statement said.

Some examples of this are people who develop a respiratory infection other than COVID-19 but can’t get access to a PCR test or one of the sought-after take-home rapid antigen tests to confirm the infection.

Similarly, there are also people who have become infected with the coronavirus, but have little to no symptoms and end up not knowing they were indeed infected.

“In the interest of efficacy, it was therefore decided to remove the delay between infection and the administration of the booster dose," said the ministry.

"It is better to give a booster dose to someone who has recently had COVID-19 than to leave someone who has not had COVID-19 without additional protection."

The statement also acknowledged that if a positive test result is confirmed, that person “could decide to wait three months, the time limit prescribed by the CIQ, before picking up their third dose.”

However, these nuances about testing and positive test results play a key role in someone’s decision of when to book a booster shot, yet they appear nowhere on the provincial government’s website or on Clic Santé.

It’s one of the reasons why some are calling for more transparency on the part of the government when it comes to delivering important health advice to the public.

“I think that a hard reboot may be necessary here to try to figure out what are the different pillars of our strategy here and what are the messages that are going out with respect to these pillars? And are these messages congruent with each other?” Vinh said.

“If you want people to be protected against Omicron, you’ll want to do it before they get infected. But once they get infected, you can't then tell them to go ahead and get vaccinated. It's not really congruent.”