County health officials determined yesterday that more parishioners at Our Lady of Lourdes Church in Massapequa Park may have been exposed to tainted communion wafers from a Christmas Mass. Officials are now asking anyone who received communion on Christmas Day or Dec. 26 to receive a free Hepatitis A vaccination.

Mary Ellen Laurain, spokeswoman for the Nassau County Health Department, said the transmission was from someone who handled the communion wafers. Hepatitis A is a generally nonfatal disease with nasty side effects. It can be treated within two weeks with a vaccine.

Health officials are offering vaccinations in the Our Lady of Lourdes Church School Auditorium today from 7 a.m. to noon, and by afternoon appointment at the Department of Health in Uniondale.