The number allowed to meet outdoors and indoors has been slashed as renewed pandemic restrictions were imposed in Northern Ireland.
The country has one of the highest rates of spread in the UK and the most recent reproductive estimate for coronavirus is 1.3.
Totals socialising indoors at households will be reduced to six from no more than two households after Stormont ministers met on Thursday to rubber stamp the change.
The limit on those attending outdoor gatherings will fall from 30 to 15.
Health Minister Robin Swann said there would be focused Police Service of Northern Ireland enforcement in infection hotspot areas.
He added: “Unless we take action now I fear it would soon have been too late to arrest further extensive spread of the virus.”
A meat plant in Co Antrim is to close for a deep clean following a coronavirus outbreak, Mr Swann said.
Cranswick Country Foods in Cullybackey processes pigs.
Mr Swann told a press conference at Stormont that at least 35 cases have been identified associated with the factory.
He added: “All the workers and recent visitors to the factory should be required to self-isolate.”
Another 51 people in Northern Ireland have tested positive for coronavirus, according to the Department of Health on Thursday.
Chief medical officer Dr Michael McBride said there was a significant increase in the number of cases among younger people.
He said that partly explained why a similar increase in hospital admissions had not yet been seen.
The medic said some of the evidence about people’s behaviour was anecdotal.
“We are seeing increased social mixing, close contact occurring in domestic settings.
“What we now need to do is act on that evidence and act on it in a proportionate way.”
He backed the Stormont Executive’s decisions around restrictions.
“I believe they send a signal to the community as a whole.
“They reflect all our concerns at the growing numbers of Covid-19 cases.”
Mr Swann attacked “armchair experts” who believed they knew better and had decided to ignore official advice.
One person has been arrested and is in police custody over “personal abuse” directed at the minister, he confirmed.