[nsnick]

If immunity acquired after infection is only for a short period, immunity acquired after a vaccine will also only be for a short period.

[FlyMoreRockets]

Very likely, yes. However, it is much less debilitating to get a shot every three months.

[woeirua]

It's unlikely that would be sustainable for long for various reasons. You're talking about needing literally tens of BILLIONS of shots a year for the forseeable future?

If immunity is not long lasting, then the only path out is global eradication. We have done it before with smallpox.

[catalogia]

Could they really manage to make a new version of the vaccine four times a year? For influenza they only do it twice a year and the vaccines are often only 50% effective (or worse.)