not a biologist, but my current understanding: immunologically naive means that your body has no prior exposure to a virus (or its variants). basically it mean

not a biologist, but my current understanding: immunologically naive means that your body has no prior exposure to a virus (or its variants). basically it means it has NFC how to deal with it. so it basically has to brute force its way to a defense against the strain. This is why you saw people with early covid cases having their immune system go haywire and a lot of the treatments for covid focused on dampening the immune system to prevent it from killing the patient. once you've seen a virus and its variants a few times your body has 'remembers' strategies on how to fight the virus. and launches those strategies against it. sometimes depending on the mutations those strategies are less effective (omicron) and your body has to create new strategies. B-cells and T-cells are how the body store and deploy these strategies.