Getting an mRNA "booster" when you've had the J&J vaccine

This starts off being about J&J, but then goes on to talk about boosters. It does go on to say

Alberts said he would like to get a dose of one of the mRNA vaccines, but that is not permitted in the United States.

I wonder what “not permitted” means? Is not approved the same thing as forbidden?

That article contains a link to an earlier (July 4) article, which says

Two FDA scientists say that they disagree that boosters are needed. [they’re leaving the FDA, but reading multiple articles, it’s not clear if they’re retiring on their own decision, or if they’re being pushed out, or how much of their leaving is driven by this]

Here’s the actual opinion piece in Lancet:

Seems to me they’re leaving by their own choice.

A former senior FDA leader told Endpoints that they’re departing because they’re frustrated that CDC and their ACIP committee are involved in decisions that they think should be up to the FDA. The former FDAer also said he’s heard they’re upset with CBER director Peter Marks for not insisting that those decisions should be kept inside FDA. What finally did it for them was the White House getting ahead of FDA on booster shots.

Thanks.

I read that Novavax expects to produce 2B doses of its vaccine in 2022.
Novavax expects to make available at least 2 bln COVID-19 vaccine doses in 2022 | Reuters
The other manufacturers continue to chug along. I wonder when we stop having a global shortage of vaccine, and have a global surplus, and how that affects recommendations.

Ah, thanks for finding that.