A first COVID infection can make the body resistant to second infection for atleast five months

If someone had a COVID-19 Coronavirus infection and has recovered from it, then their body develops resistance to a further second infection

The protection is similar to that provided by vaccination. The UK study found that the protection lasts for atleast five months.

Caveats: It is not known how long the protection will last and the study is ongoing.

While a previously infected is protected against 2nd infection, that person can still carry and transmit virus to others. PHE reports that “early evidence from the next stage of the study suggests that some of these individuals carry high levels of virus and could continue to transmit the virus to others”. So the usual COVID-19 precautions are still needed.

The study involved healthcare workers from hospitals across the UK. The study recruited mainly Young and Middle age people ; it is not known whether the study findings would apply to older age people who are the most vulnerable.

The protection is not 100%. The protective effect was noted for only 83% . So there is still a chance someone who has recovered from the 1st infection might still get a 2nd infection.

The other big concern is “the risk of reinfection from the new Covid variants spotted in the UK, South Africa and Brazil”.

The study continues and more information would be available later this year ”


PHE. Press release. Past COVID-19 infection provides some immunity but people may still carry and transmit virus
Study finds past coronavirus (COVID-19) infection provides some immunity for at least 5 months, but people may still carry and transmit the virus. Published 14 January 2021. Public Health England

Guardian Newspaper. Recovering from Covid gives similar level of protection to vaccine
PHE found immunity from earlier infection provided 83% protection against reinfection for at least 20 weeks.
Ian Sample Science editor. @iansample
Thu 14 Jan 2021 06.00

Daily Mail. Previous coronavirus infection gives people immunity for five months – MORE than the Oxford vaccine, PHE study finds. By Joe Pinkstone For Mailonline
00:01, 14 Jan 2021 , updated 11:54, 14 Jan 2021

Telegraph: Brazilian Covid variant may infect people who have recovered from virus
Scientists find new coronavirus strain has mutated to be more infectious and has changes that help it evade immune system
By Sarah Knapton,
14 January 2021 • 3:00pm

SIREN – SARS-COV2 immunity and reinfection evaluation; The impact of detectable anti SARS-COV2 antibody on the incidence of COVID-19 in healthcare workers.

SIREN protocol: Impact of detectable anti-SARS-CoV-2 on the subsequent incidence of COVID-19 in 100,000 healthcare workers: do antibody positive healthcare workers have less reinfection than antibody negative healthcare workers?

BMJ: Covid-19: Past infection provides 83% protection for five months but may not stop transmission, study finds.
BMJ 2021; 372 doi: https://doi.org/10.1136/bmj.n124 (Published 14 January 2021)
Cite this as: BMJ 2021;372:n124

Disclaimer: Please note- This blog is NOT medical advice. This blog is purely for information only and do check the the sources where cited. Please DO consult your own doctor to discuss concerns and options relevant to you.

The views expressed in this blog represent the author’s views held at the time of drafting the blog and may change overtime, particularly when new evidence comes to light. The blog is not necessarily endorsed by any organisation the author is associated with and the authors views are not in way intended to be a substitute for professional advice.