It's like only getting a quarter dose of the flu shot, your...

It's like only getting a quarter dose of the flu shot, your immune response would not kick in hard enough leaving your vaccine immune response lacking, they basically have not figured out the correct dose.
On top of that just like the flu shot it won't be any good after a year of flu virus mutations, it takes a year for the flu to mutate because it preferences the winter climate so it's a yearly cycle rolling through the population.
Covid 19 is everywhere all year round mutating constantly, there are quite a lot of current "known" variants each with a multitude of of sub variants of which any could become a new main variant with enough of a mutation to become more infectious.
Even if they get the dose right for the new vaccines we could still need 6 monthly dosing with the latest updated vaccine until the virus calms down enough for yearly vaccination (slower mutations).
In 1918 during the flu pandemic America record 3 separate waves of the pandemic roll through that year alone.
Thanks to vaccines it is little more than a foot note in history and all these "anti vaxers" (most of whom I'm willing to gamble are all vaccinated against the likes of polio ect from when they were children) think the vaccine is worse than the disease, all I can say is once they are sick it's too late to ask for a vaccine.

Even if Recce is a CURE I still think prevention is better in the first place, long covid is shaping up to be very nasty indeed....

https://www.historyofvaccines.org/content/blog/vaccine-development-spanish-flu