The move could complicate the nation’s vaccination efforts at a time when many states are confronting a surge in new cases and seeking to address vaccine hesitancy.
At the news conference, Dr. Marks drew a connection between the two vaccines, saying the cases involving rare blood clots were very similar.
Federal officials stressed Tuesday that there have been no significant safety concerns about either of those vaccines.
But while shipments of the Johnson & Johnson vaccine have been much more limited, the Biden administration had still been counting on using hundreds of thousands of doses every week.
In addition to requiring only a single dose, the vaccine is easier to ship and store than the other two.
With the Johnson & Johnson setback, federal officials expect there will only be enough to cover fewer than 230 million adults, roughly 30 million shy of the total adult population.
But a certain percentage of adults are expected to refuse shots, despite public campaigns to convince them, so the supply may cover all the demand. »