The teaching union say they are deeply concerned at the reports
Two women without facemasks were seen handing out leaflets to parents and children outside the primary school.
Parents and guardians are said to be angry after the two women began handing out fliers.
INTO General Secretary John Boyle says measures including a ban on gatherings at school gates are in place to ensure schools can open safely and says it's vital that everyone acts in a responsible manner to protect students and staff.
The leaflet claims the flu vaccine does more harm than good.
The HSE states the flu vaccine is the best way to avoid the illness and says they have been given to millions of people over the past 60 years including pregnant women.
The union is now asking for an investigation into the incident and say steps need to be taken to ensure such gatherings do not take place in the future