A healthcare worker prepares to administer a Pfizer/BioNTech Covid-19 vaccine at The Michener Institute, in Toronto ( CARLOS OSORIO)

Canadian physician falsely links Covid boosters to higher infection risk

This article is more than one year old.
Published on August 16, 2023 at 22:47
5 min read
By Gwen ROLEY, AFP Canada

A video shows a British Columbia physician presenting data from a study he claimed was proof that each supplemental dose of Covid-19 vaccine increased a person's risk of contracting the coronavirus. This is false; the author of the study said this misinterprets the data -- his main finding was that shots were becoming less effective against new strains of the virus -- and that receiving boosters does not increase risk of infection.

"There was an absolute direct linear correlation that the more shots you got, the more likely you would get Covid and the more like you would spread Covid" says Canadian doctor Charles Hoffe in a Facebook video posted August 10, 2023.

The clip -- which received more than 28,000 views -- comes from Hoffe's testimony in May to the National Citizen's Inquiry (NCI), a group unaffiliated with the government that says it is examining Canada's Covid-19 response, and whose TikTok and YouTube accounts were suspended.

AFP has previously fact-checked its panelists, including Hoffe, for spreading misinformation about the pandemic.

"This new type of vaccine turned out to be a complete failure. In fact, what they had created was not a vaccine but an anti-vaccine," Hoffe says in a different version of the video shared by Children's Health Defense on May 12 on Twitter, which has recently re-branded as "X."

Screenshot of a Facebook post taken August 16, 2023

In the clip, Hoffe alludes to a study (archived here) -- first released as a pre-print -- from the Cleveland Clinic which he claimed demonstrates increased vulnerability to the coronavirus as a person receives more doses of the shots.

The study looked at the frequency of Covid-19 among healthcare workers in Ohio during the height of the Omicron wave in 2022. While it did observe a positive correlation between the number of Covid-19 vaccine doses and infection risk, its author Nabin Shrestha, previously told AFP that this did not necessarily prove the vaccine is the cause of increased risk of contracting the disease.

"We certainly found such an association, but that does not prove that the more vaccines you get, the more likely you are to get Covid," said Shrestha, an infectious disease physician, in an interview on August 14.

"It was not something we wanted to hide, it was certainly an association, but of course we cannot talk about causation in a study like that," he said.

He said the main observation of the study was that bivalent vaccines, an updated version of the inoculation which includes components of the Omicron variant, were only moderately effective in preventing infection from the more recent strains of the virus.

Shrestha said there needs to be further research into the association he observed between higher vaccine doses and a higher number of infections, as well as the effectiveness of updated vaccines against new strains of the virus.

But he also said it is clear that Covid-19 vaccines do not decrease immunity to infection and have been effective in reducing severe illness and hospitalization.

"People go around saying that you should not get a vaccine because the vaccine causes Covid, which is absolutely wrong -- a vaccine like this cannot cause Covid," he said.

Screenshot of a post on X. taken August 16, 2023

Carlione Quach Thanh, an immunology professor at the University of Montreal and the physician in charge of infection prevention at Sainte-Justine Hospital, said the study of vaccines' effectiveness over time is part of any inoculation campaign. As new strains of a virus appear, she said a vaccine needs to be updated so immunity can adapt.

"The reason why we're still seeing this virus is because the only way for it to conquer the world -- and that's its goal -- is to either become very competitive or escape our immune response that we've developed either through infection or vaccination or both," Quach Thanh said.

In the future, she said there will likely be adjustments to Covid-19 vaccines each year to offer stronger immunity against the currently circulating strain of the virus.

Vaccines protect

Another piece of data Hoffe cited (archived here) showed a higher level of Covid-19-induced hospital and intensive care visits among vaccinated people in the Australian state of New South Wales in the last six weeks of 2022.

AFP previously fact-checked similar claims in Australia and experts said that in populations with a high proportion of vaccinated people, such as New South Wales, that demographic is more likely to be overrepresented in any general statistic, including hospitalizations and death caused by Covid-19.

"If 90 percent of your population is vaccinated with these two doses, you are of course going to have a greater proportion of your cases in the ICU that are vaccinated because you barely have any cases that are unvaccinated," Quach Thanh said.

Quach Thanh -- like Shrestha -- said being vaccinated is the best way to protect against complications from Covid-19.

"That's been well-demonstrated in all the studies, so if you're at risk of having a complication from Covid, the vaccine decreases that risk markedly," she said.

Physician suspended

This is not the first time Hoffe has spread misleading information about the coronavirus pandemic.

Hoffe was cited by the College of Physicians and Surgeons of British Columbia (CPSBC) in 2022 for promoting ivermectin as a treatment for Covid-19. Experts have previously told AFP that ivermectin is not a proven remedy for the disease and both the US Food and Drug Administration and Health Canada have advised against this use of the anti-parasite drug.

According to the CPSBC website, Hoffe's hearing has since been adjourned and local media reported he was suing a British Columbia health authority for wrongful suspension.