Coronavirus cases are rising again for residents, including ‘breakthrough’ cases in the vaccinated (corrected)
Coronavirus cases among Cambridge residents have been rising this month, slowly at first and now much more sharply. And many of those infected were fully vaccinated, the Cambridge Public Health Department said Wednesday in answer to questions from Cambridge Day.
More than half the 35 people who were infected despite being fully vaccinated had symptoms of Covid-19, but none had serious illness or were hospitalized, to the department’s knowledge.
Of 83 new confirmed and probable cases between June 1 and Tuesday, 35 were in residents who were fully vaccinated, or 42 percent of the new cases this month, the department said. Compared to the 74,480 residents who were fully vaccinated as of July 13, it’s only 0.1 percent, similar to state breakthrough case figures, the health department said. Infections among fully vaccinated individuals are called breakthrough cases.
Of the remaining 48 new cases in July, 15 occurred in children under 12 who aren’t eligible for the vaccine and therefore weren’t vaccinated. The department didn’t say how many of the other new cases were in older unvaccinated residents or those who received one shot of a two-shot series.
Susan Feinberg, spokesperson for the department, said “the increasing proportion of breakthrough cases in Cambridge” follows the statewide trend. The reason isn’t clear, she said, suggesting that “the recent increase” in Massachusetts and other states could stem from more prevalence of the exceptionally contagious Delta variant in the United States, “relaxation of mask mandates and other preventive measures, and return to everyday activities.”
Whatever the reason, “the best way to protect yourself from Covid-19 is to get vaccinated,” Feinberg said. “Even among people with breakthrough infections, the vaccines have proven to be extremely effective at preventing serious illness and death. It is important to remember that no vaccine offers 100 percent protection against illness.” Cambridge has not reported a new death since May 10; the total stands at 123.
The city’s daily coronavirus reports showed the upward trend clearly. On Tuesday, the city reported 10 new cases, the most in weeks, and on Wednesday, 19. The seven-day average rate of new confirmed cases per 100,000 population climbed from a low of 0.2 on June 16 to 5.4 on Wednesday.
Not masking up yet
Unvaccinated people and the Delta variant are fueling the increase, scientists and health officials have said. Some have called for reimposing precautions such as mask and distancing mandates. “At this time, the city is not planning to reinstate a mask mandate or other precautions,” Feinberg said. “The city and CPHD recognize that this is a fluid situation.” She added that the health department is watching the trends and “will make recommendations to the city as needed.”
Despite the lack of a mandate, the health department recommends that both vaccinated and unvaccinated people wear a mask “in situations where transmission is likely and around unvaccinated people, including children,” Feinberg said. The city is also offering a second weekly day of free testing starting July 26 at the CambridgeSide mall partly to serve people after working hours and partly because of the increasing cases. Testing will be available from 4 to 8 p.m. Monday, as well as from 11 a.m. to 3 p.m. Thursday.
The city has been struggling to persuade more residents to get vaccinated, like most other communities, although the vaccination rate exceeds the state’s figure and those in other large cities in Massachusetts. On July 14 the city held a “Summer Vaccination Party” at the King Open School where 43 people got a shot, Feinberg said.
As of July 15, there were 74,480 Cambridge residents who had been fully vaccinated and 81,418 had received at least one shot, according to the state. That works out to 73 percent of residents 12 years and older – the ones who can get the vaccine now – who are fully vaccinated and 79 percent with at least one shot.
Who has low vaccination rates
It leaves more than 37,000 residents who are not fully vaccinated and more than 30,000 without a single shot, either because they are too young, medically prevented or just won’t get vaccinated.
Residents in their 20s and older teens from 16 to 19 have the lowest vaccination rates, well below the overall city figure. About 62 percent of 20-somethings and 45 percent of older adolescents are fully vaccinated. City health officials had flagged the low rate for 16- to 19-year-olds last month and pledged to make a special effort to reach out to that age group. Still, the percentage has changed little; it was 42 percent four weeks ago. Those in the 20-to-29 year age group haven’t responded to vaccination entreaties either, with their vaccination rate at 60 percent four weeks ago.
Asked to comment on the trends in cases and vaccinations, councillor Patricia Nolan said it was “worrying,” particularly the low vaccination rate for 16- to 19-year-olds, “which we should address.” Councillor Quinton Zondervan called for a return to mask mandates indoors and masks outdoors in crowds. Schools should require masks as recommended by the American Academy of Pediatrics, he said.
Eyeing the variants
As for the Delta variant, it hadn’t shown up in Cambridge as of July 15, according to information given to the city by the state health department, Cambridge Public Health Department spokesperson Jodie Silverman said last week. That doesn’t mean it isn’t here, since the vast majority of positive Covid-19 test results in Massachusetts are not being genomically analyzed for variants. The state apparently submitted fewer than 300 test results to the Centers for Disease Control and Prevention for the month ending July 3, so it was not included in the CDC’s variant data by state.
In New England, the Delta variant accounted for an estimated 68 percent of new cases in the past two weeks, according to the CDC. It was just 42 percent in the previous two-week period.
A total of 62 cases caused by variants had been reported in Cambridge as of July 15, with 45 identified as Alpha, the more transmissible variant first found in Britain. The second-highest type was Gamma, with six cases. Gamma was first found in Brazil and Japan and has shown some ability in a laboratory study to evade vaccines and to reinfect people who have recovered from Covid-19. The proportion of Gamma variants has been declining in New England, according to the CDC.
This post was updated July 22, 2021, to correct that tests have been made available Monday and Thursday, as a wrong weekday was named, and to adjust some data throughout.