People in Northern Ireland are being urged to take part in a study which will help decide how antiviral drugs will be used to treat Covid-19.
More than 12,000 people across the UK have already signed up.
People who are over-50 or younger adults with pre-existing conditions can sign up if they receive a positive Covid-19 test and have experienced symptoms in the previous five days.
The study is currently using the drug Molnupiravir.
It was licensed for use by regulators in 2021, after trials showed promising results in reducing the risk of serious illness or death.
Prof Nigel Hart, lead investigator for the Panoramic study in Northern Ireland, said although vaccines remained the first line of defence against Covid-19, treatments were still required.
"It is important that we do have therapies that will help us to manage people who catch Covid-19 to prevent them from deteriorating, being admitted to hospital and perhaps needing to go to intensive care.
"The first drug being assessed is Molnupiravir, it's a drug which would be prescribed by a GP if the evidence came forward to say it could be prescribed."
The drug has previously been used to treat the flu.
Co-clinical lead of the Northern Ireland Clinical Research Network, Claire Leathem, said :"Of course what we don't know is how effective is it for Covid, especially in a vaccinated population and we are hoping that these antivirals will be of great benefit.
"The only way we can do that is through this trial, there is no point in anybody taking an antiviral without us really knowing - 'is it going to make a difference?'"
More than 400 people in Northern Ireland have signed up so far, but researchers are encouraging as many as possible to come forward.
'I felt exponentially better'
Elizabeth McLaughlin, a healthcare worker from Newtownabbey in County Antrim, was referred to the trial by her local GP practice.
"I began the antivirals on day five, I received them in the post. You have to take the four tablets twice a day at 12-hour intervals.
"My nurse had suggested that because I have other issues with my health that I would be an ideal candidate for it.
"I continued taking the antivirals from day five until day 10, you take them and it seems to catch just at the right time.
"I felt on day seven I was feeling exponentially better in myself, I didn't have the aches and pains that I'd had."
The study's results will help scientists understand how to roll-out anti viral treatments when they are deployed more widely later this year.
To sign up to the trial, visit the Department of Health website here.