The rollout of the Pfizer/BioNTech and Moderna Covid-19 vaccines in the US is not proceeding smoothly, which is not surprising given the logistical challenges of administering a novel vaccine that requires two doses. There are similar problems in the UK, where the Pfizer/BioNTech and Oxford University/AstraZeneca vaccines are now authorized, the latter gaining authorization just last week.
Accordingly, the British government, without public discussion and in an opaque manner, is varying the protocols for vaccine administration. The second dose of both vaccines can now be given up to 12 weeks after the first dose. And it even is permitting that different vaccines can be used for the first and second doses in some situations.… Seguir leyendo »