Coronavirus (COVID-19) Discussion Thread

[vivster]

curl-6 said:

SvennoJ said:

curl-6 said:

It's not as cut and dried as that; antibodies naturally diminish over time as they're no longer needed once an infection is cleared; what's more important to lasting immunity are Memory T Cells and B Cells as these last much much longer and 'remember' past pathogens so that a fast and effective immune response can be mounted if it is ever encountered again.

It's still not quite clear how long Acquired Immunity lasts for COVID, including after vaccination, but there is some evidence for lasting and durable immunity thanks to these memory cells.

https://www.news-medical.net/news/20200908/Memory-B-cells-indicate-durable-immunity-in-COVID-19.aspx

Unfortunately there is also evidence that people can get re-infected and even someone who died after getting covid-19 for a second time.

The problem is, it simply takes time to find this out.

There have been instances of reinfection yes, but given how few they are in relation to the tens of millions of people who've contracted COVID, it's still quite probable that immunity applies in the vast majority of cases, otherwise surely we'd be seeing far more reinfections in places where the virus is rampant. But yes, time will tell.

I still maintain it is far too early to give up on immunization when we have dozens of vaccines in trials, using a wide variety of different methods, several of which have shown promising early data. 

There are a number of factors why we're seeing very few cases of reinfection.

1. The majority of covid cases have happened very recently

2. covid survivors are more likely to take measures to prevent another infection

3. a second infection may be less likely to have strong symptoms

4. some new infections may already be reinfections but are impossible to detect as such