Share article:
Share article:

Study: Surviving Covid reduces risk of re-infection by 83%

© Belga

People who have been infected with Covid-19 have 83% less chance of being infected again, according to a study of health care workers in the United Kingdom.

However those conclusions come with a caveat: the study has only been running for five months, so is unable to predict what effect might be felt over a longer time period.

Since the start of the pandemic, stories have emerged in the media of people becoming reinfected with the virus, while a previous infection should have conferred immunity. That has led to doubts in some quarters as to the efficacy of a vaccine and how long immunity might last after vaccination.

The study by Public Health England looked at 20,000 health care workers, 6,600 of whom had previously been infected, and found that only 1% from that group became infected a second time. Some of them, however, carried a large viral load in the nose and throat, making it possible they could infect others, despite having no symptoms themselves.

Reinfection is pretty unusual, so that’s good news,” said immunologist John Wherry of the University of Pennsylvania in Philadelphia, who also took part in the study.

But you’re not free to run around without a mask.”

According to Susan Hopkins, a senior medical adviser at Public Health England who leads the study, the interim results suggest that natural immunity of 83% is almost as effective as the 90% or so achieved by vaccines – at least over a period of five months.

The study, named SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN), is ongoing, and the largest study of Covid reinfection, with systematic screening for asymptomatic reinfection.

Every two to four weeks, participants have blood tests for SARS-CoV-2 antibodies, as well as a PCR test to detect the virus itself.

Over the 5 months, the team found 44 reinfections labelled ‘possible’. In the group of 14,000 participants who had not been previously infected, 318 people tested positive for the virus.

The possible reinfections are subjected to further testing, with only two of the 44 found so far being re-graded to ‘probable’.

In the meantime, the study will turn its attention to the so-called British variant officially labelled B.1.1.7, to determine whether the protection offered by SARS-CoV-2 also works against new variants – a question of major importance to vaccine development.

Alan Hope
The Brussels Times

Latest news

More women take police selection tests in Belgium
The selection tests to become a police inspector have more and more female participants, according to figures released by Interior Affairs Minister ...
‘Absurd’: all Brussels schools should have the same Covid rules
Several city councillors for education in Brussels are calling to abolish the "absurd" differences in coronavirus measures for Dutch-speaking and ...
Massive renovations for iconic venue in the heart of Brussels
Brussels concert hall Ancienne Belgique has announced plans to renovate the AB Café and the AB Salon and is looking for a contractor fit for the job. ...
Display of child’s room in Brussels raises awareness of foster families
An exhibit that features a fictitious child’s bedroom has been on display since Tuesday at the Place d'Armes in Namur, with the support of the ...
Test results show pupils have fallen behind in Flemish schools
Learning delays have been reported in almost all subject areas in Flanders since the start of the pandemic, a trend that continued in 2021, a ...
Belgium considers relaxing testing rules for UK travellers
At the next Consultative Committee meeting, Belgium will look into relaxing the testing and entry policy for travellers coming from the United ...
Jette libraries start giving plants away with books
Visitors to libraries in the Brussels municipality of Jette will soon be able to pick up a free plant along with a book, thanks to the new Plantotek ...
‘Do what you want, but do it as safely as possible,’ experts warn
As the daily number of new coronavirus infections exceeds 3,000 for the first time since May, infectious disease expert Erika Vlieghe and ...
‘We’re running dry’: Brussels teacher shortage reaches critical levels
The teacher shortage in Brussels is affecting schools across language borders, according to Brussels’ Minister for Multilingualism and Dutch ...
New coronavirus infections above 3,000 for first time since May
The number of people testing positive for coronavirus has skyrocketed to the highest rate since the start of May 2021. Between 9 and 15 October, ...
Belgium in Brief: Getting To The Airport
When I saw the news of plans for a tram line and cycle path to connect Brussels' outskirts to the airport, my first reaction was sheer joy.  Let ...
EU should invest €5 trillion in climate plan, says State Secretary for Economic Recovery
The European Union must invest €5 trillion in its climate plan over the next decade to "retain its credibility as a political project," according ...