Immunity and the new strain

[Stokey]

We have all tested positive for coronavirus in the past week. Pretty sure it's the new strain as it started with my Y6 and a third of her classmates caught it. But we're 90% sure my husband had it back in April. No testing back then, but he was really ill for a week with a temperature over 40. This time he hasn't felt half as bad, still a temp but around 38 mark. So does that mean that immunity from the original strain does not carry over? Or was it just so long ago that he is no longer immune?

Tests still ongoing for clarification

Did your dc do singing indoors at school?

My son has previously tested positive for antibodies and currently has it again. He is in central London.

Were just going through our second bout too OP This time only ds1 and I are showing any symptoms - he's super mild and I'm having a far easier time than last time (was really sick end of March then long covid).

I had a few antibodies detected in July, these were gone by September so I'm not shocked that zI caught it again. However, it was so much milder this time that I clearly have retained some sort of immunity, even if not perfectly. I guess that's the case in your household too.

Immunity isnt a yes/no thing, esp where different strains of a virus are concerned, sometimes you can have partial immunity - which is better than nothing.