People testing negative for Covid-19 despite exposure may have 'immune memory'

[marmar]

(Guardian UK) We all know that person who, despite their entire household catching Covid-19, has never tested positive for the disease. Now scientists have found an explanation, showing that a proportion of people experience “abortive infection” in which the virus enters the body but is cleared by the immune system’s T-cells at the earliest stage meaning that PCR and antibody tests record a negative result.

About 15% of healthcare workers who were tracked during the first wave of the pandemic in London, England, appeared to fit this scenario.

The discovery could pave the way for a new generation of vaccines targeting the T-cell response, which could produce much longer lasting immunity, scientists said.

Leo Swadling, an immunologist at University College London and lead author of the paper, said: “Everyone has anecdotal evidence of people being exposed but not succumbing to infection. What we didn’t know is whether these individuals really did manage to completely avoid the virus or whether they naturally cleared the virus before it was detectable by routine tests.”

The latest study intensively monitored healthcare workers for signs of infection and immune responses during the first wave of the pandemic. Despite a high risk of exposure 58 participants did not test positive for Covid-19 at any point. However, blood samples taken from these people showed they had an increase in T-cells that reacted against Covid-19, compared with samples taken before the pandemic took hold and compared with people who had not been exposed to the virus at all. They also had increases in another blood marker of viral infection. ............(more)

https://www.theguardian.com/world/2021/nov/10/people-exposed-to-covid-yet-not-falling-ill-may-have-immune-memory-finds-study

[Throck]

1. Is this the first sign of herd immunity?

[cadoman]

3. I think the article is saying we'll be able to receive new vaccines that help our T-Cell immunity

Or maybe it will be packaged up into the existing ones somehow?

[FakeNoose]

2. I've heard of false positive readings on Covid tests

... however this is the first I've heard of false negative readings.

If it's happening often enough, maybe we'll never beat this thing.