Very crafty you are. The topic "very urgent warning" could be a topic about anything. It is vague enough that anything can be said as long as it sounds urgent. You have made a place for yourself. A place where you can be off topic while using exclamation points, bold fonts and all caps.
I know, but the principle is basically the same. Hopefully a vaccine will have the affect it had on smallpox and some of those other little nasties that ran around before. Time will tell.
The problem with the flu is that the vaccine protects against the 3 or 4 most prevalent flu-virus strains from last year. However, since it is by no means certain that those same 3 or 4 strains will cause most flu infections this year, the vaccine doesn't guarantee that you won't catch the flu even after getting a vaccination. Washing hands and wearing a mask might even offer just as much protection (but getting a flu-jab seems like a good idea anyway if you're at risk of complications). Let's just hope the vaccine against Covid doesn't end up like the flu vaccine, offering only partial protection.
The There are discussions in other groups that the vaccines may only offer partial protections and for limited periods of time. We have to wait and see. There's also new advice out that old folks need a stronger dose of the current flu vaccines, so in the future there may be different dosages of flu shots.
You may be aware, the problem is usually 'antigenic drift', but it may 'drift' (or shift) only a little - thus the body may have some immunity to new strains because of a percentage of similarity to past ones (via passive or acquired immunity). With some viruses immunity may be short-lived (and it is looking that way in Covid-19) or very long-term (even a lifetime). Covid-19 could become another 'seasonal flu' like illness and is always with us and changing.
From what I have read, immunity after recovering from Covid-19 is not well understood yet. There has been some research done on antibodies prevalence in former patients and the results don't look promising (hardly anyone with antibodies still present 6 months after recovery). However, that's only part of the immunity story. The human body also has T-cells, which serve as a sort of "memory bank" against previously encountered viruses. These T-cells can quickly mount a defense in case of renewed infection. The very very few cases where people have twice gotten sick with Covid-19 are too insignificant. Significant continued mutation of the SARS-COV2 virus similar to the flu virus, would obviously pose a serious problem for bringing it under control with vaccines. Disclaimer: I'm not an expert, so I may have understood some of this wrong.
Your posts on Covid-19 are actually extremely good. And am I correct that a few months ago you posted that, not having English as a first language, you could not compete with others here? If I remember this correctly, then clearly you very much under-estimated yourself.