https://news.yahoo.com/trump-dismisses-covid-19-booster-184022005.html
It sounds like Trump is now beginning to publicly cast some doubt on the vaccines. He's starting cautiously, by questioning the booster shots, but I suspect (hope) that he will be slowly ramping up the questioning and criticism going forward, from here on out.
Here’s the video from an interview with Hannity where he admits receiving it (JnJ I believe), time stamp 3:30: https://nypost.com/2021/04/19/trumps-urges-americans-to-get-vaccines-takes-shot-at-jj-pause/
That's too bad. This may be an area where he could get better advice.