[EvaH (OP)]

Joan wants to know:

Please advise me if it is possible that survivors of this virus were protected, even to a limited extent, by having had a regular flu jab in recent years? It occurs to me, as a layman, that there may have been an element in past jabs containing protection, however small. Are they testing for that?

Can you help?

[Colin2B]

Joan wants to know:

..is (it) possible that survivors of this virus were protected, even to a limited extent, by having had a regular flu jab in recent years? ............Are they testing for that?

There are currently studies going on that look at what is known as bystander immunity. This is where a previous infection of flu or another Coronavirus eg cold might give some immunity. Although there is no clear proof there are indications that this might be the case and it has been suggested that one reason children seem to get less intense reactions to CV19 is because they more often get flu and colds. There is certainly evidence that a Sars1 infection creates T cells that are still active after 17 yrs and these may infer some immunity against CV19 even though they are not antibodies.
A very interesting area to watch.

[set fair]

There are currently studies going on that look at what is known as bystander immunity. ...
A very interesting area to watch.

Any links please Colin?

[Colin2B]

There are currently studies going on that look at what is known as bystander immunity. ...
A very interesting area to watch.

Any links please Colin?

This is one coming out on T cell immunity rather than antibody https://news.ki.se/immunity-to-covid-19-is-probably-higher-than-tests-have-shown