Re the inOban post: I mentioned earlier (it was deleted for reasons unknown) that I know for a fact that a young couple in my road (nurse and careworker) were ill and tested positive in March and were again ill and tested positive in December. I therefore concluded that this means that there could be a need for two vaccinations per annum, at least in the beginning. This is relevant to this thread if airline passengers will be required to provide proof of vaccination. It might well be that any such proof/certificate will expire after 6 months.