The new P.1 variant of COVID-19 found for the first time in travelers from Brazil has been detected in Massachusetts more than anywhere else in the country, and most of these cases are part of a cluster on Cape Cod, according to researchers.
New data from the Broad Institute of MIT and Harvard showed 54 cases of variant P.1 were reported in Massachusetts – mainly on Cape Cod – during the month following the first reported case of the variant in the state in late February.
“When you see that there are many [P.1] cases in Massachusetts, partly because we’re looking for it, ”said William Hanage, associate professor of epidemiology at the Harvard TH Chan School of Public Health. “It was expected to happen at some point and it certainly did now.”
The research suggests that 43 of these cases form a single cluster that is likely linked to an introduction from Brazil, with the remaining cases of P.1 possibly originating from Nebraska, Italy, and other areas, he said.
“Most of [the 54 total cases] are associated with a single cluster because, as we know … most cases do not transmit, ”said Hanage. “Those who transmit, however, compensate.”
The P.1 cases have not continued to rise in the state, but Hanage expects more to emerge.
Research shows that the variant spreads faster than the original COVID-19 strain, but scientists still need to learn whether it is more deadly or more likely to reinfect those who have already recovered from the virus.
The introduction of the variant is a new source of concern on Cape Cod.
About half of all counties in Barnstable County are at high risk for transmission, according to the state’s weekly public health report COVID-19. Most also saw an increase in case rates and positivity in recent weeks, a sign that a new outbreak could hit the area if those numbers continue to grow.
At the same time, more residents of the Cape were vaccinated than in any other region of Massachusetts.
The state’s weekly vaccination report shows that 44% of Barnstable County residents received at least one dose of vaccine on March 30 – the highest percentage in the state. The county also had 27% of its population fully vaccinated at that point, second only to Martha’s Vineyard.
Hanage said the variant cases on Cape Cod were detected when fewer people in the state had been vaccinated. Although vaccines are likely to be effective against this new strain, he said Massachusetts still has a long way to go before it can repel variants of the virus.
“In order to completely exclude this virus, we need to vaccinate many more people than we have already vaccinated,” said Hanage. “High vaccination rates [right now] they are not enough to be protective and, if we allow more transmission, we will have more cases ”.
Caroline Enos can be contacted at [email protected]. Follow her on twitter @CarolineEnos.