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

Police are looking for the driver of this truck after it nearly hit a group of kids in Esquimalt on Thursday. (Photo courtesy of Victoria Police)
Victoria police looking for driver of truck that nearly missed kids before crashing in Esquimalt

The truck’s driver, a man, fled the scene after the truck crashed into a house’s fence

Rainbow trouts thrashing with life as they’re about to be transferred to the largest lake of their lives, even though it’s pretty small. These rainbows have a blue tinge because they matched the blue of their hatchery pen, but soon they’ll take on the green-browns of their new home at Lookout Lake. (Zoe Ducklow/News Staff)
VIDEO: Lookout Lake stocked with hatchery trout to delight of a seniors fishing club

The Cherish Trout Scouts made plans to come back fishing soon

A driver stopped by Saanich police following a road rage incident on April 15 was found to be impaired, in violation of a license restriction and in a damaged vehicle. They received a 90-day driving prohibition and a 30-day vehicle impound. (Saanich Police Traffic Safety Unit/Twitter)
Driver stopped on Pat Bay Highway after road rage reports fails breathalyzer test: police

Several witnesses reported driver to Saanich police, school officer intercepted

Police escorts for Victoria bylaw workers entering encampments in parks will continue for this month, after council approved a $25,000 budget request from VicPD. (Black Press Media file photo)
Victoria bylaw staff encampment work to include police escort through April

Taxpayers to see modest increase in property taxes for 2021

Victoria’s bylaw restricting businesses from providing most plastic checkout bags came into effect on April 15. (THE CANADIAN PRESS/Paul Chiasson)
Victoria’s bylaw banning plastic bags back in effect

The bylaw restricts businesses from providing most plastic checkout bags, charges for alternatives

A woman wears a protective face covering to help prevent the spread of COVID-19 as she walks past the emergency entrance of Vancouver General Hospital in Vancouver, B.C., Friday, April 9, 2021. COVID-19 cases have been on a steady increase in the province of British Columbia over the past week. THE CANADIAN PRESS/Jonathan Hayward
Top doctor warns B.C.’s daily cases could reach 3,000 as COVID hospitalizations surge

There are more than 400 people in hospital, with 125 of them in ICU

(Black Press Media file photo)
POLL: Do you have a plan in place in the event of a tsunami?

Tsunamis have claimed the lives of more than 250,000 people between 1998… Continue reading

Anyone with information on any of these individuals is asked to call 1-800-222-TIPS (8477) or visit the website victoriacrimestoppers.ca for more information.
Greater Victoria Crime Stoppers wanted list for the week of April 13

Greater Victoria Crime Stoppers is seeking the public’s help in locating the… Continue reading

The District of Sooke will continue to flower with Communities in Bloom. (Pixabay)
Sooke will bud but not bloom in provincial competition

Council scales back participation in Communities in Bloom

An armed officer walks outside Cerwydden Care on Cowichan Lake Road near Skinner Road Wednesday, April 14 around 5:30 p.m. (Kevin Rothbauer/Citizen)
Police standoff at Duncan apartment ends peacefully

Officers surround building as homeowner held in apartment for nearly four hours by adult son

Latest modelling by public health shows cases generated by COVID-19 infections into places where it can spread quickly. (B.C. Centre for Disease Control)
Industrial sites, pubs, restaurants driving COVID-19 spread in B.C.

Infection risk higher in offices, retail, warehouses, farms

Hwy. 4 was shut down in both directions for 10 hours on March 23 as a rock bluff was blasted as part of Kennedy Hill’s ongoing construction. Commuters can expect five more 10 hour closures on five consecutive Wednesdays beginning April 28. (Photo courtesy of Ministry of Transportation and Infrastructure)
Five 10-hour Pacific Rim highway closures planned in the next 6 weeks

Closures needed for rock blasting as part of the Kennedy Hill Safety Improvement project.

Bulldogs forward Stephen Castagna flips the puck into the Clippers zone during a game on Oct. 24. (ELENA RARDON / ALBERNI VALLEY NEWS)
Island BCHL game postponed due to ‘potential positive’ COVID-19 test

Nanaimo Clippers team suspends activities, players isolating pending further test results

Most Read