Three-quarters of patients who tested positive for COVID-19 after numerous large public events in a Cape Cod town were fully vaccinated, according to a federal study published Friday.
Among the 469 COVID-19 cases identified, 346, or 74%, occurred in fully vaccinated people, the Centers for Disease Control and Prevention report found. Most of the vaccinated patients, 79%, experienced symptomatic breakthrough infections. Testing from 133 patients revealed that the delta variant was responsible for 90% of the cases.
Of the five COVID-19 patients who required hospitalization, four were fully vaccinated. No deaths were reported.
The CDC this month identified 469 cases of COVID-19 among Massachusetts residents linked to summer events and large public gatherings in the Barnstable County town that were held from July 3 to July 17. At the time, 69% of eligible residents were vaccinated.
Starting July 10, the Massachusetts Department of Public Health began receiving rising numbers of reports of COVID-19 cases among individuals, including those fully vaccinated, who live in or recently visited Barnstable County. People who tested positive for COVID-19 said they had attended crowded indoor and outdoor events at venues such as bars, rental homes, guest houses and restaurants.
The state health department had reported a 14-day average of zero coronavirus cases per 100,000 people per day in residents of the Barnstable County town as of July 3, the report says. But two weeks later, the average jumped to 177 cases per 100,000 people per day.
“Findings from this investigation suggest that even jurisdictions without substantial or high COVID-19 transmission might consider expanding prevention strategies, including masking in indoor public settings regardless of vaccination status, given the potential risk of infection during attendance at large public gatherings that include travelers from many areas with differing levels of transmission,” the CDC study authors wrote, noting the high transmissibility of the delta variant.
A big majority of the cases, 85%, occurred in males, with the median age 40. Of the patients who were fully vaccinated and experienced breakthrough infections, 301, or 87%, of them were males with a median age of 42.
Most of the breakthrough infections occurred in people who had received the Pfizer-BioNTech vaccine, which accounted for 46% of the cases. The Moderna vaccine was involved in 38% of breakthrough infections, while Johnson & Johnson made up 16%.
On Tuesday, the CDC released new guidance advising all people, vaccinated or unvaccinated, to wear face masks in indoor public settings in areas with high COVID-19 transmission.
Health, The New York Today