The British Islamic Medical Association have issued specific advice urging Muslims observing Ramadan not to delay getting the vaccine, drawing on analysis from Islamic scholars which says that injections for non-nutritional purposes do not invalidate the fast.
Further information is available here: COVID-19 Vaccine Hub - Statements | British Islamic Medical Association (britishima.org)
The Public Assessment Reports contain all the scientific information about the trials and information on trial participants.
For the Pfizer trial, participants included 9.6% black/African, 26.1% Hispanic/Latino and 3.4% Asian.
For the Oxford/AstraZeneca vaccine 10.1% of trial recipients were Black and 3.5% Asian.
There is no evidence either of the vaccines will work differently in different ethnic groups.