Coronavirus

[Mike T]

Antibodies were found in almost all (96%) of those who had a previous infection confirmed by a swab test. If T cell immune response was important without B cell help - antibodies - I would have expected that % to be rather lower. It is important to differentiate between immunity - implying resistance to infection - and immune response, where infection may still occur but may be milder/asymptomatic.

A Royal College of Physicians survey showed that 25% of doctors who replied had tested positive, despite most having had face to face contact with many cases. So, either PPE works, or test results are falsely low - probably a bit of both. But rising cases in many countries suggests that documented herd immunity has yet to be reached anywhere, apart from perhaps some boroughs in New York.

A Swedish immunologist has been quoted as saying that opening schools would help achieve herd immunity, and that opening schools would be safe - both cannot be right. Sweden has had 3 to 7 times the deaths of its neighbours per head of population.