Covid Survivors May Need Just One Shot Of 2-Dose Vaccines, Say Studies.

Covid Survivors May Need Just One Shot Of 2-Dose Vaccines, Say Studies

If you already had the virus, your immune response after one vaccine is likely to be even better.

Coronavirus vaccines were just rolling out in December when more than 1,000 staffers at Cedars-Sinai Medical Center in Los Angeles volunteered for a sweeping study. The goal: pinpoint how immune reactions to the jab might vary.

By last month, a clear pattern in the data "popped out at us," said research leader Susan Cheng. Those who had recovered from Covid-19 responded to their first shot so robustly that the results rivaled never-infected colleagues who had received both shots. The implication was clear. If you've had Covid, you may only need one of the two doses recommended by Pfizer and Moderna.

"We did not expect that this was going to jump out like a smoking gun," said Cheng, who co-authored the Nature Medicine write-up. In fact, if you already had the virus, your immune response after one vaccine is likely to be even better than a never-infected person's after two, according to Italian research just out in the New England Journal of Medicine.

The issue of giving only a single dose to people who have had Covid has become all the more urgent since safety concerns have been raised about Johnson & Johnson's and AstraZeneca's vaccines. The implications at a time of strained global supply are striking: giving previously infected people just one mRNA vaccine shot could free up more than 110 million doses worldwide, according to a calculation by University of Maryland School of Medicine immunologist Mohammad Sajadi and colleagues.

'Remembering' Covid

Sajadi co-authored one of the recent studies that fit into a recent flurry of findings all pointing in the same direction: The immune system in people who've had Covid "remembers" the virus, so a first vaccine acts as a powerful booster for existing defenses. "The data is very clear," Sajadi said. "Every study has shown you get a very clear and strong memory response."

o66rtd8o

Healthcare workers administer doses of the Pfizer-BioNTech Covid-19 vaccine at an arena on the campus of San Diego State University in San Diego, California.

Since February, several European countries -- including France, Spain, Italy and Germany -- have adopted policies giving Covid survivors just one dose of the two-dose vaccines.

In Israel, a world leader on coronavirus vaccinations, health authorities initially withheld vaccines altogether from recovered Covid patients, but in February recommended they receive one shot. New research there suggests that the booster vaccine adds protection against newer variants that originated in the U.K., South Africa and Brazil.

"We think that our study supports the recommendation to administer one vaccine dose to recovered individuals to protect against the original and SARS-CoV-2 variants of concern," Michal Mandelboim, head of Israel's National Center for Influenza and Respiratory Viruses, said in an email. A study in "Science" found that in Covid survivors, vaccinations massively boosted immunity against variants.

In the U.S., the Centers for Disease Control and Prevention still recommends two vaccine doses for people who have had Covid, but the mounting evidence that one vaccine could be enough is under discussion. The U.S. has administered enough doses for 31% of its population, while Israel has given enough for 57%, according to the Bloomberg Vaccine Tracker.

Data Needed

In a blog post, National Institutes of Health Director Francis Collins raised the possibility that giving survivors a single dose could "help to extend vaccine supply and get more people vaccinated sooner."

"But any serious consideration of this option will require more data," he cautioned in February.

Since then, one study after another has reinforced the single-vaccine-for-survivors idea, though some skeptics have pointed out that it is logistically simpler to just give everyone two doses than to figure out who needs only one.

In the U.S., vaccine supplies are relatively copious, Sajadi said. But "for other countries, especially places that are having a hard time getting vaccine, this is really still an important question. And it's also an important question in general because you don't want to just give someone a medical intervention they don't need."

If a patient who'd had Covid asked Sajadi at this point whether they needed a second vaccine, he said, he'd say it would make sense to skip it if nothing in their medical history indicated issues with immune responses.

Cheng at Cedars-Sinai said she would still default to the CDC guidance calling for two vaccines, even for people who've had Covid. The data does suggest, however, that one dose could be enough, she said -- and that could be true for other types of people as well: "I think we're just at the tip of the iceberg of figuring out who they are."

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

NDTV News

NDTV.com provides latest news from India and the world. Get today’s news headlines from Business, Technology, Bollywood, Cricket, videos, photos, live news coverage and exclusive breaking news from India.

https://www.ndtv.com/

Related news

3 Injured In Shooting At New York's Times Square

A shooting in New York's bustling Times Square has injured two women and a four-year-old girl, in an incident US authorities were still scrambling to understand, police said Saturday.

NDTV News

Sadiq Khan, London's Feisty Mayor, Wins Second Term.

London Mayor Sadiq Khan, who won re-election Saturday, has risen from humble roots to spar with prime ministers and presidents since taking charge of the British capital five years ago.

NDTV News

Dozens Injured In New Jerusalem Clashes

Dozens more people were injured Saturday as Israeli police fired water cannon and rubber bullets to disperse Palestinian protesters in annexed east Jerusalem, a day after fierce clashes at the city's...

NDTV News

Kamala Harris and Second Gentleman caught kissing with masks, 'Tucker' reacts.

Kamala Harris and Second Gentleman caught kissing with masks, 'Tucker' reacts.

'Watters World' host Jesse Watters asks why kids can be crammed together at the border but couples can't dance on their wedding on 'Tucker Carlson Tonight.' #FoxNews #Tucker Subscribe to Fox News! Watch more Fox News Video: Watch Fox News Channel ...

Examining whether police should enforce traffic stops.

Examining whether police should enforce traffic stops.

ABC News’ Devin Dwyer looks at calls to remove police from traffic enforcement in the wake of violent and deadly encounters from routine stops.

Where does nuclear power fit in as the U.S. begins moving away from fossil fuels

Where does nuclear power fit in as the U.S. begins moving away from fossil fuels

President Biden aims to cut the country's carbon emissions by half by 2030, and move to a net-zero carbon economy by 2050. Central to that plan is investments in renewable energy sources, like wind, solar and hydroelectric power. But what about nu...

Climate expert weighs in on Biden's promise to cut greenhouse gas emissions.

Climate expert weighs in on Biden's promise to cut greenhouse gas emissions.

President Biden is making climate change and the environment one of the key agenda items of his administration. The president has promised to cut greenhouse gas emissions in half by 2030. He says that goal can be reached by passing his $2 trillion...

7 4

«We haven't got over the line, that's quite clear from the ballots».

«We haven't got over the line, that's quite clear from the ballots».

"We haven't got over the line, that's quite clear from the ballots" Shadow transport secretary Jim McMahon "it's pretty clear from the way that the ballots are landing that we are not close to winning this despite our best endeavours."

Trey Gowdy predicts US will 'be drawn back into conflict' in Afghanistan.

Trey Gowdy predicts US will 'be drawn back into conflict' in Afghanistan.

'Special Report' panel discuss how the US should handle Afghan interpreters left behind as troops head home. #FoxNewsSubscribe to Fox News! Watch more Fox News Video: Watch Fox News Channel Live: FOX News Channel (FNC) is a 24-hour all-encompassin...