The Public Health Inspectors Union says public behaviour at vaccination centres is disappointing.
Chairman of the Union Upul Rohana said individuals queuing up for vaccinations are not adhering COVID-19 health guidelines.
He noted failed to follow health regulations will result in a vaccination cluster emerging.
Rohana said large crowds are gathering at vaccination centres, exceeding numbers stipulated.
He added technical committees cannot be deployed to manage crowds.
The PHI Union Chairman said they observed that social distancing was not maintained while face masks were not being worn in the suitable manner.
He claimed that the public may contract COVID-19 even before being vaccinated and strengthening immunity through the vaccine, thereby leading to a vaccine cluster.
He noted that the Delta virus variant is rapidly spreading, with cases rising significantly.
Upul Rohana therefore requested the public to strictly follow health guidelines.