[aphextron]

>If the vaccine only confers a few months of immunity, like the yearly flu vaccine, how long does it take to develop, produce and distribute the update?

The Pfizer and Moderna vaccines are mRNA based, which means the iteration time is measured in weeks. The production process is massively simplified; it's just a chemical process like any other drug, rather than needing to be incubated in chicken eggs like a flu vaccine. The first mRNA vaccines for SARS-CoV-2 were being administered within 2 months of the outbreak. If these things work (and they do; phase 2 trials have shown immunogenicity 3-4 times higher than COVID convalescent plasma [0]), and they are proven to be safe in widespread usage, it will potentially revolutionize vaccine development. COVID could end up saving lives in the long run for the fact that it sped up the timeline on mRNA vaccines by a decade.

[0] https://www.medrxiv.org/content/10.1101/2020.08.17.20176651v...