Sign up for Englemed updates from TwitterSign up for Englemed updates from Facebook
Contact Englemed
Our contact email address.
We can provide a specialist, tailored health and medical news service for your site.
Click here for more information
RSS graphic XML Graphic Add to Google
About Englemed news services - services and policies.
Englemed News Blog - Ten years and counting.
Diary of a reluctant allergy sufferer - How the British National Health Service deals with allergy.
BookshopFor books on women's health, healthy eating ideas, mental health issues, diabetes, etc click here

WWW Englemed
Copyright Notice. All reports, text and layout copyright Englemed Ltd, 52 Perry Avenue, Birmingham UK B42 2NE. Co Registered in England No 7053778 Some photos copyright Englemed Ltd, others may be used with permission of copyright owners.
Disclaimer: Englemed is a news service and does not provide health advice. Advice should be taken from a medical professional or appropriate health professional about any course of treatment or therapy.
Shear wave scans could improve brain tumour surgery
Mon March 1st - A new ultrasound technique may be the best way to detect cancer tissue missed during removal of tumours from the brain, researchers report today. More
On 09/10/2020 William Haworth wrote:
How long is recovery time after proceedure... on Ablation cuts atrial fibrillat...
On 08/02/2018 David Kelly wrote:
Would you like to write a piece about this to be i... on Researchers unveil new pain re...
On 23/10/2017 Cristina Pereira wrote: on HIV breakthrough - MRC...
On 12/09/2017 Aparna srikantam wrote:
Brilliant finding! indeed a break through in under... on Leprosy research breakthrough...
On 01/07/2017 Annetta wrote:
I have been diagnosed with COPD for over 12 years.... on Seaweed plan for antimicrobial...

COVID-19 immunity could last at least eight months

Friday January 8th 2021

Almost all COVID-19 survivors have the immune cells necessary to fight re-infection for at least eight months after the initial infection, according to a US study.

The research at La Jolla Institute for Immunology, San Diego, California, is believed to be the biggest study, for any acute infection, that has measured all four components of immune memory – antibodies, memory B cells, helper T cells and killer T cells at the same time.

The team, co-led by Professor Alessandro Sette with Professor Shane Crotty, research assistant Professor Daniela Weiskopf, analysed 188 COVID-19 survivors and found that although antibodies decline over time, they had T cells and memory B cells to fight re-infection.

“Our data suggest that the immune response is there and it stays,” said Prof Sette, whose findings are published in Science.

It means COVID-19 survivors could have protective immunity against serious disease from the SARS-CoV-2 virus for months, perhaps years after infection. However, the authors caution that protective immunity varies significantly between individuals.

They found that virus-specific antibodies remain in the bloodstream months after infection and that memory B cells could reactivate and produce SARS-CoV-2 antibodies to fight re-infection.

When they looked for memory B cells specific for the SARS-CoV-2 spike, they found that they increased in the blood six months after infection.

COVID-19 survivors also had T cells ready to fight re-infection, while memory CD4+ "helper" T cells and many memory CB8+ "killer" T cells also remained, ready to destroy infected cells.

The researchers said the different parts of the adaptive immune system work together, which meant that COVID-fighting antibodies, memory B cells, memory CD4+ T cells and memory CD8+ T cells in the blood more than eight months following infection was a good sign.

“This implies that there's a good chance people would have protective immunity, at least against serious disease, for that period of time, and probably well beyond that,” said Prof Crotty.

However, the researchers saw a 100-fold range in the magnitude of immune memory, which could mean that people with a weak immune memory may be vulnerable to a case of recurrent COVID-19 or could be more likely to infect others.

Finding that immune memory against SARS-CoV-2 is possible is also a good sign for vaccine developers, say the authors.

“It is possible that immune memory will be similarly long lasting similar following vaccination, but we will have to wait until the data come in to be able to tell for sure,” said Prof Weiskopf.

“Several months ago, our studies showed that natural infection induced a strong response, and this study now shows that the responses last. The vaccine studies are at the initial stages, and so far, have been associated with strong protection. We are hopeful that a similar pattern of responses lasting over time will also emerge for the vaccine-induced responses.”

The researchers are to continue analysing samples from COVID-19 patients and hope to track their responses 12 to 18 months after the onset of symptoms. They are also examining how immune memory differs across people of different ages and how that may influence COVID-19 case severity.

Dan JM, Mateus J, Kato Y et al. Immunological memory to SARS-CoV-2 assessed for up to eight months after infection. Science 7 January 2021; doi: 10.1126/science.abf4063

Tags: Flu & Viruses | North America

Printer friendly page Printer friendly page

Comment on this article:

<a>,<b> & <p> tags allowed
Please enter the letters displayed:
(not case sensitive)