Is a fourth COVID-19 vaccine dose coming?

Could we soon be rolling up our sleeves for a fourth COVID-19 vaccine shot?
The Centers for Disease Control and Prevention has not recommended another dose just yet, but some doctors say it seems likely – especially as the vaccine's effectiveness goes down over time.
The CDC released a new study last week on the vaccine effectiveness after the third dose. It showed that effectiveness went down from 91% to 78% protection four months after getting the booster.
Other countries, such as Israel and Sweden, have both started giving out a fourth dose of the mRNA vaccine. Doctors say results there will be informing the decisions made in the U.S.
An FDA official also suggested a fourth dose of the COVID-19 vaccine might be needed closer to fall – when residents usually line up for the flu shot.