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COVID-19: How long are you protected for if you've already had coronavirus
People who have had COVID are likely to be protected from reinfection for at least 5 months and have a similar defence to someone who's been vaccinated, according to a UK study.
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But does it mean those who have recovered are no longer a risk to others? And could the protection last any longer? Here's what you need to know.
Who did the study follow and is it reliable?
More than 20,000 healthcare workers from 102 NHS trusts across the country, including frontline staff, have been tested since June by the Public Health England (PHE) Siren study. Some 6,614 of them tested positive for antibodies at the start of the research, suggesting they'd had the virus previously in the first wave.
It's a big group of people so its results are valuable - and the study is still ongoing.
How many people contracted COVID a second time?
There were only 44 potential reinfections from the 6,000-plus found to have antibodies.
Two of them were deemed “probable” cases, while 42 were “possible”, based on the evidence available.
What does it mean for the chances of
contracting the virus again?
If all 44 cases are assumed to be confirmed reinfections, the protection rate is 83% compared with those who’ve not had it before.
If only the two “probable” cases are considered, the rate would be 99%, but researchers are going with the headline figure of 83%. However, PHE said in a statement online more work is going on to clarify this range.
How long does the protection last?
It appears to be at least five months, on average, from first getting sick. The analysis of the results was done towards the end of 2020, and the study is still following the participants to see if it lasts longer.
It means people infected in the first wave last spring could now be at risk of getting coronavirus again. The study’s lead, Professor Susan Hopkins, warned the protection “is not total and we do not yet know how long [it] lasts”. Despite the uncertainties, Dr Julian Tang - a clinical virologist - said in a statement online the results were still “useful and reassuring news” for medics on the frontline.
It's also important to note that the study was done before the new UK variant - which transmits far more easily - had become widespread.
How does this 'natural' protection compare
protection after two shots. aren’t sure yet - as the vaccines haven’t been deal with new variants of the virus - such as
on?
They say early evidence suggests some
No - in light of the risk of potentially still being able to spread coronavirus, people must still stick to the law and government guidelines. Scientists are therefore also looking at whether PHE stresses it’s “crucial that everyone "first wave" antibodies provide protection continues to follow the rules and stays at against it. home, even if they have previously had
with vaccines? This means continuing to stick to lockdown Vaccines being rolled out in the UK, such as as social distancing, wearing a face covering the Pfizer and Oxford jab, can offer over 90% and regular handwashing.
In terms of length of protection, scientists and will I show symptoms? around long enough to see how long people The two “probable” reinfection cases in the are immune for. study said their symptoms were less severe The vaccines may also have to be tweaked to sure. the one that’s been identified recently in Brazil. However, if it were to follow other If I’ve had COVID before, can I still pass it out more minor.
COVID-19”. measures and practise safety protocols such
Will COVID be ‘easier’ the second time,
the second time - but it’s too early to say for coronaviruses, a second infection could turn
Professor Lawrence Young, a virologist from It’s very possible, and the study’s authors warn Warwick Medical School, said in a statement that a person with antibodies may still be a studies on common cold coronaviruses clear risk to others. indicate that any reinfection “is unlikely to result in severe disease”. people with immunity could carry high levels of But one notable difference with getting the virus in the nose and throat, and potentially COVID-19 again, appears to be the likelihood pass it on. of not showing any symptoms at all.
Can I be more relaxed if I’ve been infected before?
The study found people who were reinfected were significantly more likely to be asymptomatic (66%) than those contracting COVID for the first time (22%).
