The Food and Drug Administration appears poised to make available the COVID-19 vaccines that target omicron as a second booster for people with weak immune systems and those ages 65 and older.

Federal health officials are convening with outside advisers April 6 to talk about a vaccine plan, whether that's another booster in the fall, an omicron shot or one that targets more than one strain.

Health officials argue the protection of the COVID vaccine booster wanes over time and say some people need a second booster. But other infectious disease experts say three shots are enough for now.

People who are 50 and older and certain immunocompromised individuals may get a second Pfizer-BioNTech or Moderna COVID-19 vaccine booster four months after they received the first.