Three cases of a coronavirus variant initially detected in Brazil have been identified in Ireland for the first time, the National Public Health Emergency Team (Nphet) said on Friday night.
All of the cases are directly associated with recent travel from Brazil.
Deputy chief medical officer Dr Ronan Glynn said: “This P1 variant has previously been identified in a small number of European countries, including France, Germany, Italy, the Netherlands and Spain.
“While there is currently no microbiological or epidemiological evidence of any change in transmissibility of P1, this is plausible.
“Further studies are required to determine whether this variant is likely to have an impact on vaccine effectiveness or infection severity.”
The Brazil variant could be much more contagious or easy to catch than the original version of coronavirus.
It has undergone changes to its spike protein – the part of the virus which attaches to human cells.
It first emerged in July.
Dr Glynn said anyone who has recently travelled from Brazil, or 19 other countries designated as “category two”, is required by law to quarantine at home for 14 days.
Earlier on Friday, Nphet reported an additional 28 Covid-linked deaths in the Republic, along with 763 newly confirmed infections.