The Equality and Human Rights Commission (EHRC) said it understood firms will want to protect their staff and their customers by requiring employees to be vaccinated, but it advises them to take other factors into consideration.
In the UK, Transport Secretary Grant Shapps has suggested it is a good idea for people to be double jabbed before returning to the office but it will not be required by legislation.
An EHRC spokesman said: “Employers are right to want to protect their staff and their customers, particularly in contexts where people are at risk, such as care homes.
“However, requirements must be proportionate, non-discriminatory and make provision for those who cannot be vaccinated for medical reasons.”
Professor Stephen Reicher, a member of the Scientific Pandemic Insights Group on Behaviours (Spi-B), which advises the Government, also told The Guardian that making vaccines mandatory may be reasonable for those in jobs where they are responsible for the physical care of others, but the negatives outweighed the benefits for other employers.