I sincerely hope the concerns raised about the Oxford/Astra Zenica vaccine, and indeed any other vaccine can be quickly resolved to the satisfaction of the regulators.
All the announced vaccines apparently have superseded the WHO's, 50% efficacy target, and by considerable margin.
The particular peculiarity of the Ox/A-Z Vaccine where by the 50% first dose combined with the second dose seems to have led to better results than two full strength doses is a strange and very interesting result. I am sure that will lead to further testing to see how the dose size affect efficacy.
Assuming any of these vaccines do receive a licence, testing won't stop. As the number of recipients increases, the data about efficacy will continue to be recorded, and firmer information will develop about infection prevention, and how long theses vaccine's will provide effective protection.
We must also bear in mind there is already evidence of the virus mutating, and that might mean the present vaccines may lose efficacy. But as we now have a starting vaccine, if or when we need to modify a vaccine to meet a mutation, we do now have starting point and that should help kickstart the development of a revised vaccine.