Superspreader events, in which one person infects a disproportionately large number of others, are the primary means by which the coronavirus spreads, new research suggests.

The researchers also found 70% of people infected with the coronavirus didn't pass it to anyone else and that all superspreading events involved indoor social gatherings.

"Now we know which measures might give you the most bang for your buck — if we could stop the superspreading from happening, we'd benefit the most people," Cowling said.

A South Korean churchgoer infected 43 others in February, a singer infected 53 people at a choir practice in Washington a month later, and a New York lawyer was responsible for passing the coronavirus to more than 100 others in his community.

Within the community-spread cases, more than half were connected to six superspreading events.

The term "superspreader" refers to an infected person who transmits the virus to more people than a typical infected person would.

But in the case of these Hong Kong superspreading events, one person infected at least three times that many people.

In fact, 20% of cases caused 80% of transmissions, a majority of which were linked to superspreading events at a wedding, temple, and multiple bars in the city's Lan Kwai Fong district.

The remaining 20% of transmissions were result of another just 10% of cases, when infected patients passed along the virus to one, or at most two, other people — generally someone in their households. .

"Social exposures produced a greater number of secondary cases compared to family or work exposures," the study authors wrote, adding that reducing superspreading events could have a considerable effect in lowering the virus' R0.

Coronavirus superspreader events have shared a few key characteristics: They've involved indoor gatherings in which a lot of people from different households were in close, extended contact.

Instead, there's a type of activity that gives people access to a greater number of people in areas conducive to the virus' spread, Cowling said.

"You can't have a superspreading event unless there are a lot of people around, so you have to be very careful still about gatherings of people of any size — that includes religious services," William Schaffner, an infectious-disease expert at Vanderbilt University, previously told Business Insider

Japan's success stems from adherence to the "3 C's rule." The government told people to avoid closed spaces, crowded places, and close-contact settings — all of which are ripe for superspreading events