Studies suggest people who have been infected with the novel coronavirus may produce 10 to 45 times the antibodies after the first dose of the Pfizer-BioNTech or Moderna vaccines, compared with those who haven’t had COVID-19. The research is yet to be peer-reviewed. (AP Photo/Esteban Felix)

Studies suggest people who have been infected with the novel coronavirus may produce 10 to 45 times the antibodies after the first dose of the Pfizer-BioNTech or Moderna vaccines, compared with those who haven’t had COVID-19. The research is yet to be peer-reviewed. (AP Photo/Esteban Felix)

People infected with COVID-19 may need just one dose of vaccine, studies say

People who have had COVID-19 appear to produce 10 to 45 more times the antibodies after 1st vaccine dose

Scientists at the National Advisory Committee on Immunization are reviewing research that suggests people who have been infected with COVID-19 can turbocharge their antibodies with just one dose of a vaccine.

The committee is “actively reviewing evidence on the protection offered by one dose for those previously infected, and whether a second dose continues to be necessary,” says a statement from the panel.

Caroline Quach-Thanh said the committee is “debating” the question of how many vaccine doses someone who has been infected with COVID-19 requires.

“France and Quebec have said only one,” said Quach-Thanh, chair of the committee, in an email.

Studies have suggested people who have had COVID-19 may produce the required antibody response with just one dose of a vaccine.

A letter in the New England Journal of Medicine earlier this month says the question of whether one dose is enough “requires investigation.” It’s written by 32 researchers from the Icahn School of Medicine at Mount Sinai in New York after conducting a small study.

It suggests people who have been infected with the novel coronavirus may produce 10 to 45 times as many antibodies after the first dose of the Pfizer-BioNTech or Moderna vaccines compared with someone who hasn’t had COVID-19. The research is yet to be peer-reviewed.

Quach-Thanh said data shows that the response to the first dose of vaccine is strong for those who have been infected with the virus.

“Like a booster dose,” she said.

Those who have been infected and get a second shot may also have stronger side-effects, such as fever, aches and feeling tired, which are signs their immune system is already primed, Quach-Thanh said.

“The question that remains is: is that true for everyone or at least for the vast majority?”

Dr. Bonnie Henry, British Columbia’s provincial health officer, said early data from around the world suggest people who have had a lab-confirmed positive test for COVID-19 get a good response from just one dose of a vaccine.

“The jury is still out but more and more it is looking like they get a really strong booster effect from a single dose and a second booster may not be necessary,” she said.

Quebec’s public health director, Horacio Arruda, told a news conference earlier this week that immunization experts believe a single dose of vaccine, when given three months after recovery from the disease, provides the same amount of immunity as two doses.

A second dose, Arruda explained, is not recommended for people who have had COVID-19 because “it doesn’t give more immunity, and it brings more significant adverse effects,” such as flu-like symptoms.

Prof. Fiona Brinkman of Simon Fraser University’s molecular biology and biochemistry department said the number of antibodies produced by a person may depend on how severe their COVID-19 infection was.

That does not mean people need to get an antibody test done before getting a vaccine, although that may change, she added.

“Right now, the policy is that we’re just vaccinating everybody and doing that first dose.”

However, Quach-Thanh warned that the presence of antibodies is not, in itself, a sign of protection and they are all not created equal.

“Some people without much antibodies will have protection, while others with antibodies may not be that well protected,” she said.

Brinkman said it’s also possible that there may be a difference in the kind of antibodies produced after a COVID-19 infection and a vaccine.

“The most important thing is to have these certain antibodies — what we call neutralizing antibodies — that we really want,” she said, adding the vaccines have been shown to produce them.

The experts said there is no harm in those who have been infected with COVID-19 getting both shots.

The statement from the committee said it is also evaluating how long someone previously infected with COVID-19 could wait before getting a vaccine, based on emerging evidence.

Brinkman said one of the concerns researchers have is how long immunity might last.

“This disease literally hasn’t been around long enough to allow us to appropriately assess how long you have antibodies and an immune response that will be effective against this virus, if you’ve either been vaccinated or you’ve had the disease.”

Researchers said it could also potentially mean that the vaccine can be delivered into arms faster because a number of people may only need one dose of the shot.

“It really is good news,” Brinkman said. “If anything, it’s a good thing.”

Coronavirusvaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Photo screen-shot from School District 51’s website
COVID-19 infection confirmed in Boundary School District

Those potentially exposed to the virus have been told to self-isolate, says acting Superintendent

Stock image.
Judge tells Grand Forks man accused of theft to guard his personal property

Edward ‘Joe’ Wright is accused of a break and entering at a flood-damaged property in North Ruckle

Photo: Laurie Tritschler
Greenwood man to stand trial for alleged stabbing

Grand Forks provincial court will set a trial date next month

Grand Forks Mounties look on as a tow truck prepares to haul an SUV involved in a Highway 3 crash near the intersection of Spraggett Road Friday, April 9. Photo: Laurie Tritschler
First responders attend Highway 3 crash in Grand Forks

No one appears to be hurt in the two-vehicle crash which highway stopped traffic in both directions

Restaurant patrons enjoy the weather on a patio in Vancouver, B.C., Monday, April 5, 2021. The province has suspended indoor dining at restaurants and pubs until at least April 19 in B.C. due to a spike in COVID-19 numbers. THE CANADIAN PRESS/Jonathan Hayward
B.C. sets new COVID-19 daily record with 1,293 cases Thursday

New order allows workplace closures when infections found

Thursday, Feb. 4: RDKB Chief Engineer Darryl Funk hoists a banner commemorating last year’s championship season by the Bantam House Bruins. Photo: Laurie Tritschler
Bantam Bruins honoured at hair-raising banner ceremony at Grand Forks’ Jack Goddard Arena

Asst. coach Mike Tollis said he reluctantly gave in to the team’s victory wish that he cut his pony tale

In Ontario, COVID-19 vaccine clinics have been set up at local mosques. (Submitted photo: Rufaida Mohammed)
Getting the vaccine does not break your fast, says Muslim COVID-19 task force

Muslim community ‘strongly’ encouraging people to get their shot, whether or not during Ramadan

A plane is seen through the window on the tarmac of Vancouver International Airport as the waiting room is empty. THE CANADIAN PRESS/Jonathan Hayward
100+ international travellers who landed in B.C. refused to quarantine

The Public Health Agency of Canada says it issued $3,000 violation tickets to each

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

A health-care worker holds up a vial of the AstraZeneca Covishield vaccine at a COVID-19 vaccination clinic in Montreal, Thursday, March 18, 2021. THE CANADIAN PRESS/Paul Chiasson
PHAC receives first report of blood clot linked to AstraZeneca

The federal agency says the person is now recovering at home

A real estate sign is pictured in Vancouver, B.C. THE CANADIAN PRESS Jonathan Hayward
1 in 3 young Canadians have given up on owning a home: poll

Data released Monday says 36% of adults younger than 40 have given up on home ownership entirely

Dr. Bonnie Henry gives her daily media briefing regarding Covid-19 for the province of British Columbia in Victoria, B.C, Monday, December 7, 2020. THE CANADIAN PRESS/Jonathan Hayward
B.C. urges people to stay in their neighbourhoods, discourages out-of-household meet-ups

Dr. Bonnie Henry says there should be no travel, even to the next city over

Dr. E. Kwok administers a COVID-19 vaccine to a recipient at a vaccination clinic run by Vancouver Coastal Health, in Richmond, B.C., Saturday, April 10, 2021. THE CANADIAN PRESS/Jonathan Hayward
Most Canadians plan to get COVID-19 vaccine, but safety fears drive hesitancy: poll

This comes as confidence in governments is plummeting in provinces being hit hardest by the pandemic

Marathon of Hope runner Terry Fox is shown in a 1981. (THE CANADIAN PRESS/CP)
Terry Fox’s legacy of resilience resonates during COVID-19 crisis, says brother

Fred Fox said his brother’s legacy of resilience has taken on renewed resonance as COVID-19 rages on

Most Read