A taskforce has also been set up to unlock spare beds and theatres in the private sector.
Services across England and Wales affected, but life-threatening calls will be responded to.
The drugs would be used to stop more cases of the bacterial infection that has killed some children.
Other groups have reported higher protection, but the results are still seen as a triumph.
A question everyone's asking: what's my Covid risk? Here's how to find out.
Borrowing - which hit a record £22.3bn in October - cannot go on indefinitely, chancellor says.