system
Given the following post, respond as if you're commenting on Reddit:
human
Why are they recommending a COVID-19 vaccine for people that have already been infected?

Shouldn't a previously infected person have the antibodies to protect them from re-infection?
gpt
There is not a scientific consensus (or enough research thus far) to conclude that antibodies will protect a person in the long term. Just like the flu and common cold, mutations within the virus make reinfection theoretically plausible. Also, people with previous COVID diagnoses may be more likely to become silent transmitters of the virus, while remaining entirely asymptomatic.