JPMorgan Chase changed course on its big annual healthcare conference it intended on holding in person in San Francisco next month after key attendees dropped out on Covid fears.

The bank on Wednesday told participants that the 40th Annual J.P. Morgan Healthcare Conference was moving to a virtual format “out of an abundance of caution,” according to emails obtained by CNBC.

“The health and safety of our clients and employees is of the utmost importance and given the on-going COVID-19 pandemic, we have made this decision,” the bank said. “We were not only hopeful to meet in-person but also understand how much this conference means to the San Francisco community, which we fully support.”

The event is known as one of the largest gatherings of healthcare executives in the world and a hotbed for deals activity for the industry. JPMorgan took action after biotech firms including Moderna and Amgen pulled out of the conference, a move reported Tuesday by Stat News.

While the companies didn’t explain why they had pulled out, John Maraganore, outgoing CEO of Alnylam Pharmaceuticals, tweeted yesterday that the JPMorgan conference should go virtual to “avoid a super-spreader event and a PR disaster for our industry.”

JPMorgan had planned on holding the conference on January 10 through 13 at the Westin St Francis. In previous years, the hotel has been so packed with attendees that executives used nearby parks, department stores and even bathrooms to hold meetings.

When it was to be held in person, attendees were required to be vaccinated and masked indoors, according to the bank. But companies have had to take steps amid concern over the more contagious Omicron variant of covid, pushing back return to office targets, for instance.

Now, the bank said that all the conference sessions will be streamed via webcasts “and will take place in Eastern Time.”

With reporting from CNBC’s Bertha Coombs and Jodi Gralnick.