The Prime Minister has paid tribute to the collective action taken to defeat coronavirus.
He praised the massive social effort in Northern Ireland.
Boris Johnson toured a facility at Queen’s University Belfast, which is carrying out genomic sequencing on the virus.
He said: “The biggest thing I take away really so far is the amazing ability of people to come together and defeat it; collective action in the form of the lockdown and everyone observing the discipline that they did.
“There has been a massive social effort here in Northern Ireland and across the whole of the country.”
He praised the achievements of science after meeting some of the researchers at Queen’s and said a year ago he could not have imagined several vaccines would be available for Covid-19.
He looked at how scientists are sequencing the Brazil variant during his visit on Friday.
He said: “This is technology that did not exist a few years ago, and it is happening here in Belfast.
“It has been awesome to see the way science has turned the searchlight, the spotlight on the disease and enabled us really to begin to beat it.”
Mr Johnson also toured a mass vaccination centre at a leisure centre in Enniskillen, Co Fermanagh, as part of his one-day visit.
Northern Ireland’s vaccination effort is outstripping expectations.
Those aged 60 and over are receiving the jab, as well as people with underlying health conditions who are vulnerable.
The UK government has agreed to deploy 100 members of the military to Northern Ireland to support the “accelerated rollout” of Covid-19 vaccines.
Medically-trained members of the armed forces have been sent to support health service staff.
The request for military support was made by Stormont’s Department of Health and granted by Defence Secretary Ben Wallace.
He said: “Today I authorised the deployment of 100 defence medics to support the vaccine rollout in Northern Ireland from the end of this month.
“Our armed forces are once again stepping up to support the UK’s response to the pandemic, working around the clock to protect our people in all four corners of the nation.”
Schools have begun to accept their first pupils back after weeks of tough post-Christmas lockdown.
Vaccinations are a key weapon in the effort to reopen society in time for summer.
Northern Ireland Secretary Brandon Lewis said: “As we continue our mass Covid-19 vaccination rollout across the UK, I am pleased medically-trained personnel from our Armed Forces will support health and social care teams in the delivery of this unprecedented programme across Northern Ireland.”
One more person has died with Covid-19 in Northern Ireland. Another 208 people tested positive.