Coronavirus re-infection and immunity

Many Viral infections give some sort of immunity to the person infected. For example, if a child has chicken pox, then the child develops immunity to further chicken pox. This immunity can even be life long for many children.

But some viral infections don’t result in significant immunity to further infection. For example, Flu and Common Cold viruses infections do not result in effective long immunity. That’s why flu vaccines are given yearly to vulnerable people.

It was hoped that a Coronavirus infection could result in at least some sort of long immunity to further infections.

A recent report of man who developed Coronavirus/ COVID-19 for the second time is worrying. If this is a widespread phenomenon and not an isolated case, then it has significant implications for the current pandemic.

Herd immunity, whereby many people are immune to further Coronavirus infection either through previous infection or Vaccination, was suggested as the way of ending the current pandemic.

This report, if confirmed to be true across significant sections of population, would indicate a much more longer duration of COVID-19 pandemic.


1. BBC news: Covid reinfection: Man gets Covid twice and second hit ‘more severe’
By James Gallagher
Health and science correspondent

2. Lancet Infectious diseases. Genomic evidence for reinfection with SARS-CoV-2: a case study. Richard L Tillett, PhD, Joel R Sevinsky, PhD, Paul D Hartley, PhD, Heather Kerwin, MPH, Natalie Crawford, MD, Andrew Gorzalski, PhD, et al.
Published:October 12, 2020. DOI:

3. Lancet Infectious diseases. What reinfections mean for COVID-19. Akiko Iwasaki
Published:October 12, 2020. DOI: AWD

4. Edridge AWD, Kaczorowska et al.Seasonal coronavirus protective immunity is short-lasting.Nat Med. 2020; (published online Sept 14.) in Article

5. Tillett RL et al. Genomic evidence for reinfection with SARS-CoV-2: a case study.Lancet Infect Dis. 2020; (published online Oct 12.) in Article

6. To KK-W et al. COVID-19 re-infection by a phylogenetically distinct SARS-coronavirus-2 strain confirmed by whole genome sequencing.Clin Infect Dis. 2020; (published online Aug 25.) in Article

7. Van Elslande J et al.Symptomatic SARS-CoV-2 reinfection by a phylogenetically distinct strain.Clin Infect Dis. 2020; (published online Sept 5.) in Article

8. Prado-Vivar B et al.COVID-19 re-infection by a phylogenetically distinct SARS-CoV-2 variant, first confirmed event in South America.SSRN. 2020; (published online Sept 8.) (preprint) in Article

9. Dearlove B et al. A SARS-CoV-2 vaccine candidate would likely match all currently circulating variants.Proc Natl Acad Sci USA. 2020; 117: 23652-23662View in Article

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 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 is likely to change overtime, particularly when new evidence comes to light. The blog is not necessarily endorsed by any organisation the author is associated with and views are not substitute for professional advice.