A NEW study has revealed that indoor gatherings carry with them the "highest risk" of Covid-19 transmission.
As a result, Christmas parties, whether in the office or at home, look to be well and truly off the cards in Ireland this year.
The study, commissioned by the National Public Health Emergency Team (NPHET), found that places where people are likely to be singing and shouting increase the risk of spreading the virus significantly.
The Health Information and Quality Authority (HIQA) found that most coronavirus clusters happen in household settings.
Under Level Five restrictions, indoor gatherings are banned, while pubs, bars and restaurants remain closed, only offering takeaway services. But things would change if Ireland were to drop down to Level Three.
HIQA say they share NPHET's current stance on the opening of pubs and restaurants, according to Dublin Live.
They say that indoor settings with large groups, as well as poorly-ventilated environments where people engage in 'boisterous behaviour, insufficient use of face coverings and prolonged interaction between people' means there is a higher risk of Covid-19 transmission.
HIQA's review looked at international evidence, although there is as yet no Irish data available.
Representatives of the hospitality industry have frequently hit out at the lack of proof that Covid-19 outbreaks are caused by their sector, and have questioned the necessity for the pubs and bars to remain shut.
HIQA deputy chief executive Dr Mairin said: "The international evidence highlights the main factors that contribute to spread of Covid-19 are indoor settings, crowds and prolonged contact with others.
"Our findings reinforce the importance of adherence to self-isolation guidance, despite the challenges it can pose, for those with Covid-19, those awaiting test results and those with symptoms suggestive of Covid-19.
"This means following the HSE guidance on self-isolation including staying indoors, in a room with a window you can open, and completely avoiding contact with other people, including where possible other household members, for at least ten days."