The British Islamic Medical Association have issued statements to recommend that both vaccines are suitable for use in the Muslim community.

Pfizer vaccine:

Position Statement on the Pfizer/BioNTech Covid-19 Vaccine | British Islamic Medical Association (britishima.org)

AZ vaccine:

https://britishima.org/covid19-vaccine-az/

Islamic Medical Association Recommends Oxford/AstraZeneca Vaccine for Muslims | About Islam