Good, realistic piece here on preclinical trial data for the Oxford vaccine. https://www.biocentury.com/article/305211 

This part especially: “Setting expectations could be as important as creating vaccines and therapies. Vaccines will do no good if they are shunned by a public that is confused about the efficacy or disappointed by anything less than complete protection.”

Nice article here from last year about vaccines and how long they provide protection: https://www.sciencemag.org/news/2019/04/how-long-do-vaccines-last-surprising-answers-may-help-protect-people-longer#