A medical conference of an American biotechnology company on February 26-27 led to 300,000 COVID-19 cases till October, as per an in-depth analysis published in the journal Science. The virus strain spread to as many as 29 US states and in Australia, Sweden and Slovakia.

Cambridge-based biotech firm Biogen hosted the event in Boston, which saw the participation of guests from multiple countries. At the time when the event was held, the US had 30 confirmed cases of COVID-19, The New York Times data showed.

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Following the conference, several attendees starting falling ill. Although earlier it was believed that the event led to 99 virus cases, an in-depth analysis showed as many as 300,000 people were infected. It spread rapidly in Boston and affected several homeless centres.

The analysis of 28 cases linked to the event showed each of them were infected with a particular strain of coronavirus, C2416T, which was not previously reported in the country.

Before the event, there were just two cases of the the strain in two patients in France. 

The strain was later responsible for 1.9% of the total virus cases in the United States till October, the analysis showed.

Biogen, on Saturday, issued a statement saying that the pandemic “had a very direct and personal impact on the Biogen community — as it has on many communities across the country and world,” The NYT reported.

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“As a company rooted in science, we understand the value of the data that came from the first wave of the pandemic in the Boston area and we hope that information gleaned from these data will help continue to drive a better understanding of the transmission of this virus and efforts to address it,” it added.