Where Angels Fear to Tread
One thing seems certain about any vaccine that finds preferment: it will not have been trialed for very long  and it will not be possible to determine its long term effectiveness or harms.
Another question is will it have been trialed on the elderly and infirm - the very people who are at most at risk from the disease - or only the healthy and young? If the latter, will it be possible to determine anything about its wider safety and usefulness?
Will the young and healthy be better off acquiring some kind of immunity from the disease than having the vaccine (given the nature of immunity from this disease is anyhow somewhat uncertain)? And surely many will have already had the disease by the time there are such products. This invokes the issue of ‘primum non nocere’.
What is required in such circumstance is open discussion about the benefits and risks of such a programme, and - individually - fully informed consent, which British law requires at present, even if it seems sometimes to be only observed in the breach.
What the public does not deserve is heavy handed talk about herd immunity or compliance. It was not encouraging to read a recent discussion on the topic on MedPage Today . However serious our global predicament this may be even less the way to go than ever.
 Elisabeth Mahase, ‘Covid-19: What do we know so far about a vaccine?’, BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1679 (Published 27 April 2020)
 Ratzan, Larson & Rabin, ‘The Coronavirus Vaccine Race Is On — Someone will win, but then what?’ , MedPage Today 20 April 2020, https://www.medpagetoday.com/infectiousdisease/covid19/86041
Competing interests: AgeofAutism.com, an on-line daily journal, concerns itself with the potential environmental sources for the proliferation of autism, neurological impairment, immune dysfunction and chronic disease. I receive no payment as UK Editor