A Catholic Church diocese is suspending the "sign of peace" between Mass goers due to the recent surge in flu cases in Northern Ireland.
The Diocese of Down and Connor has also advised priests to disinfect their hands before they distribute Holy Communion.
It says its precautions are based on medical advice.
The handshakes between worshippers, known as the "sign of peace", is an established part of the Mass.
However, it is also one of the easiest ways the flu virus can spread from one person to another.
Earlier this week, health authorities in Northern Ireland said people should prepare for a possible surge in cases of the strain which hit Australia in 2017.
Now the diocese of Down and Connor has suspended the handshakes. It has also said that in the short term wine will not be distributed as part of Holy Communion, because it is done from a shared chalice.
'Huge amount of pressure'
The diocese says its precautions are based on medical advice. The same measures were taken in Catholic churches across much of the UK during the H1N1 swine flu epidemic of 2009.
Parishioners who think they may have flu have been asked to stay away from Mass.
Fr Martin Magill, of the St John's parish in Belfast, said he believed people would understand the need for the precautions.
"I think all of us are aware of the huge amount of pressure that our hospitals are under at this stage and so this idea of doing something that will make a difference," he said.
"It's precautionary more than anything else."