The CEO of Pfizer is saying that we'll need a booster within a year.
From https://www.cnbc.com/2021/04/15/pfizer-ceo-says-third-covid-vaccine-dose-likely-needed-within-12-months.html
From https://www.cnbc.com/2021/04/15/pfizer-ceo-says-third-covid-vaccine-dose-likely-needed-within-12-months.html
Quote:
Pfizer CEO Albert Bourla said people will "likely" need a booster dose of a Covid-19 vaccine within 12 months of getting fully vaccinated. ...
He also said it's possible people will need to get vaccinated against the virus annually.