A COVID-19 cluster in Provincetown that prompted officials there to issue an indoor mask-wearing advisory earlier this week has grown to 256 confirmed cases, a town official said.
On Monday, town officials said from July 1 through July 16, 132 positive COVID-19 cases had been identified, a “vast majority” in fully vaccinated people. But as of Tuesday, the number of cases had nearly doubled, Town Manager Alex Morse wrote in a Facebook post. Officials are investigating the vaccination status of those who tested positive, he said.
Of those who tested positive, 190 are Massachusetts residents, 109 of whom live in Barnstable County, Morse said. The rest live outside Massachusetts. Those who were fully vaccinated and tested positive are largely experiencing mild symptoms, officials said.
“Public health authorities continue to strongly urge Provincetown’s residents, local businesses, and visitors to follow the precautions outlined in the advisory released Monday, July 19 regardless of vaccination status,” Morse said.
The town is advising people to wear masks indoors “where social distancing cannot be achieved.” The advisory also urges businesses to require customers to show proof of vaccination when social distancing is not possible.
Officials are encouraging “anyone experiencing even mild symptoms” and anyone who has had close contact with someone who tested positive to get tested, regardless of vaccination status. Morse said more than 3,000 COVID-19 tests have been administered in town since July 1.
Morse said a mobile COVID-19 testing unit will remain at the Veterans Memorial Community Center parking lot, where vaccines are also being administered, until July 30.
On Tuesday, public health officials in Boston recommended that residents who have traveled to Provincetown since July 1 be tested for COVID-19, self-isolate, and avoid gatherings for at least five days, regardless of vaccination status, after 35 local cases were traced back to the cluster. The “overwhelming majority” of the people who tested positive had been fully vaccinated.
A number of local public health experts said they suspected the large number of breakthrough cases is caused by the highly transmissible Delta variant. The outbreak also demonstrates how vaccines are highly effective in preventing serious illness and hospitalization, they said, saying the situation would be significantly worse in a community with a lower vaccination rate than Provincetown.
Morse said on Monday that 114 percent of the eligible population has been fully vaccinated, a number that accounts for vaccination rates among part-time residents. According to state data, 76 percent of eligible Barnstable County residents are fully vaccinated.
Provincetown officials said Monday that the infections were not attributable to a single super-spreader event, and at least 32 different businesses have cases associated with them.
Dr. William Hanage, an associate professor of epidemiology at the Harvard T.H. Chan School of Public Health, told the Globe on Tuesday that multiple exposure opportunities could indicate the presence of the Delta variant because of its “rampant ability to be infectious and get into the next host.”
The outbreak comes as Provincetown, an LGBTQ+ summer hotspot, is at the height of its tourist season. During the summer, the town’s population balloons from 3,000 to 60,000, Morse said.
Dr. Cassandra Pierre, a hospital epidemiologist at Boston Medical Center and an assistant professor at Boston University, said Tuesday she thinks implementing an indoor mask mandate in Provincetown would be appropriate because of the possibility that unvaccinated people are transmitting the virus.
“There are concerns that I have that this event does potentially represent that unvaccinated individuals are also in the mix, removing masks, being in close proximity, being in indoor settings, and not potentially being as careful about risk and exposure,” Pierre said. “Reintroducing that mask mandate would provide that additional layer of protection that will provide safety to vaccinated individuals but much more to unvaccinated individuals.”
On Monday, Steve Katsurinis, chair of the Provincetown Board of Health, said officials are monitoring the situation closely and suggested more restrictions could be forthcoming if the outbreak is not contained.