In addition to protecting against serious illness and death from COVID-19, the vaccines also protect against long-term Covid, a new study suggests.
Scientists in the UK found that fully vaccinated Britons who got breakthrough cases were about half as likely to report long-term Covid symptoms as unvaccinated people who were infected.
In addition, the researchers found that only 0.2 percent of study patients who were fully vaccinated later tested positive for Covid – showing that the vaccines can prevent infection.
The study was based on self-reported symptoms from a Covid tracking app and further research is needed to substantiate these findings.
But dr. Francis Collins, director of the National Institutes of Health (NIH), called the study “encouraging” in a comment article on Tuesday.
Vaccination protects against long-term Covid in addition to serious illness, a new study finds. Pictured: A Pittsburgh resident gets vaccinated at a clinic run by the Allegheny County Health Department, September 2021
Fully vaccinated patients who received Covid were about half as likely to have prolonged symptoms (longer than 28 days) as unvaccinated patients, researchers found
The Covid vaccines currently available in the US have proven to be highly effective in protecting people from serious illness and death.
from more than 176 million Americans who were fully vaccinated against Covid in early September, only 14,000 had a breakthrough infection leading to hospitalization or death.
To a lesser extent, the Covid vaccines also protect recipients from simply becoming infected with Covid and passing the virus on to others.
But for many clinicians and patients, Covid — the condition in which patients experience Covid symptoms weeks or months after their infection — has long been an unanswered question.
A survey of health professionals in Israel found that long-term Covid is possible after a breakthrough infection.
The Israeli researchers found that one in five breakthrough cases resulted in long-term Covid – but that was a small study, with only 39 breakthrough cases in total.
A new study from the UK similarly shows that long-term Covid is possible after a breakthrough infection – but the risk of long-term symptoms is much lower for vaccinated patients than for unvaccinated.
The study was published in The Lancet Infectious Diseases early September.
For this study, researchers from King’s College London used data from the COVID Symptom Study app, a free mobile app developed by health company ZOE.
This app allows Brits to track their Covid symptoms on a daily basis, while also logging test results, vaccination status and other health information.
More than 1.2 million app users reported being vaccinated between December 2020 – when vaccines first became available in the UK – and July 2021.
Of those 1.2 million, the researchers found, about 6,000 tested positive for Covid two weeks after their first vaccine dose (but before their second dose).
A smaller number — about 2,400 — tested positive for at least a week after their second injection.
In other words, only 0.2 percent of fully vaccinated individuals later developed a Covid infection – demonstrating how well the vaccines work.
App users who had breakthrough cases were less likely to report nearly all major Covid symptoms, with fully vaccinated users reporting milder cases than partially vaccinated users
The researchers compared these app users who had breakthrough cases with both vaccinated users who did not test positive for Covid and unvaccinated users who developed non-breakthrough infections.
When comparing breakthrough and non-breakthrough cases, the researchers found that Covid was generally a milder experience for those who had received their injections.
“In infected vaccinated individuals, almost all symptoms were reported less frequently than in infected unvaccinated individuals,” the researchers wrote in their paper.
These common symptoms include loss of smell, cough, fever, headache, and fatigue.
They also noted that vaccinated individuals were more likely to have an asymptomatic case — while unvaccinated patients were more likely to require hospitalization.
Vaccinated people who got breakthrough cases were also less likely to show signs of long-term Covid — which the researchers defined as symptoms lasting 28 days or longer.
Specifically, fully vaccinated individuals who had breakthrough cases were about half as likely to have long-term symptoms than unvaccinated individuals.
This reduced risk of long-term Covid after a breakthrough case is compounded by the overall reduced risk of getting Covid after vaccination.
The British researchers also analyzed demographic factors of the breakthrough group.
They found that older adults were more likely to have a breakthrough than younger adults.
Older adults themselves were more at risk if they had other vulnerable conditions.
Also at risk: people living in low-income areas and those who are obese.
This study is based on health information that patients self-report, meaning the findings should be taken with a grain of salt.
The researchers noted that users of the COVID Symptom Study app were mostly women in their analysis and lived in high-income areas, which may have biased the findings.
Still, NIH Director Collins said these findings provide “encouraging news” in commentary on the NIH Director’s Blog.
“These latest findings provide the encouraging news that help is already out there in the form of vaccines, which offer a highly effective way to protect against COVID-19 and significantly reduce the chances of getting lung COVID if you get sick,” he wrote.
To further study long-term Covid – including post-vaccination risks – the NIH has launched the RECOVER initiative, which will study tens of thousands of Covid survivors.
This initiative was announced in February 2021 and began awarding grants to researchers this summer.