A resurgence in coronavirus cases is "inevitable" as the current restrictions are eased, a Dáil committee has heard.
TDs have been warned there needs to be a significant step up in testing and contact tracing if a reintroduction of restrictions is to be avoided later this year.
It comes as the Cabinet is expected to approve moving to phase three of the easing of lockdown restrictions and allowing 'air bridges' to other countries.
Face coverings are also set to be made mandatory on public transport, amid plans to increase the capacity of buses, trains and trams.
At the Dáil special committee today, Professor Paddy Mallon - infectious diseases consultant at St Vincent's and UCD - said the health service needs to be prepared for an increased spread of the virus.
He explained: "I and others in the infectious diseases clinical community believe it is inevitable that we will experience a resurgence of cases as we relax restrictions and permit more travel.
"In this context, control of [the virus] within our communities through a highly effective programme of rapid testing, contact tracing and community actions becomes a priority in maintaining our national biosecurity."
He said countries or areas can go from being largely COVID-19 free to having to introduce significant restrictions for large swathes of the population in a "matter of days".