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.

References:

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: https://doi.org/10.1016/S1473-3099(20)30764-7

3. Lancet Infectious diseases. What reinfections mean for COVID-19. Akiko Iwasaki
Published:October 12, 2020. DOI:https://doi.org/10.1016/S1473-3099(20)30783-0Edridge AWD

4. Edridge AWD, Kaczorowska et al.Seasonal coronavirus protective immunity is short-lasting.Nat Med. 2020; (published online Sept 14.)https://doi.org/10.1038/s41591-020-1083-1View 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.)https://doi.org/10.1016/S1473-3099(20)30764-7View 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.)https://doi.org/10.1093/cid/ciaa1275View 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.)https://doi.org/10.1093/cid/ciaa1330View 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)https://doi.org/10.2139/ssrn.3686174View 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.

Is Chloroquine useful in treatment of Corona Virus?

Chloroquine and the related drug Hydroxy-Chloroquine are drugs commonly used to prevent and treat Malaria infections; and treat some Joint conditions.

During the initial stages of COVID-19 pandemic, there were some reports of Chloroquine being useful in treating Corona Virus.

A Chinese trial published in British Medical Journal BMJ now reports that ” Administration of hydroxychloroquine did not result in …. any meaningful antiviral benefits… compared to standard of care alone in patients admitted to hospital with mainly persistent mild to moderate covid-19

Chloroquine was not only useless but it had significant side effects in a minority. So Chloroquine or Hydroxy-Chloroquine should not be used routinely outside a clinical trial setting.

References

1. Hydroxychloroquine (HCQ). Wiki. https://en.m.wikipedia.org/wiki/Hydroxychloroquine

2. BMJ. Chloroquine and hydroxychloroquine in covid-19. BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1432 (Published 08 April 2020)

3. Hydroxychloroquine in patients with mainly mild to moderate coronavirus disease 2019: open label, randomised controlled trial. BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1849 (Published 14 May 2020)

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 publication 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.