Johnson & Johnson’s easy-to-deliver Covid-19 shot is the vaccine of choice for much of the developing world.Yet the American company, which has already fallen far behind on its deliveries to poorer countries, late last year quietly shut down the only plant making usable batches of the vaccine, according to people familiar with the decision.The facility, in the Dutch city of Leiden, has instead been making an experimental but potentially more profitable vaccine to protect against an unrelated virus.The halt is temporary — the Leiden plant is expected to start churning out the Covid vaccine again after a pause of a few months — and it is not clear whether it has had an impact on vaccine supplies yet, thanks to stockpiles.But over the next several months, the interruption has the potential to reduce the supply of Johnson & Johnson’s Covid vaccine by a few hundred million doses, according to one of the people familiar with the decision. Other facilities have been hired to produce the vaccine but either aren’t up and running yet or haven’t received regulatory approval to send what …
