Mass. hospitals see significant number of COVID breakthrough cases

Massachusetts General Hospital (MGH), a Boston teaching hospital. (Hadley Green for WBUR).
Massachusetts General Hospital (MGH), a Boston teaching hospital. (Hadley Green for WBUR).

If you’re vaccinated and you get COVID-19, the chance you’ll need hospital care is still very rare. In Massachusetts, the rate of all vaccinated people who have been hospitalized is 0.05%. But as COVID cases surge, hospitals are reporting a significant portion of patients who’ve had their initial vaccine shot — or shots — and a few who’ve received a booster as well.

At major hospitals around the state, anywhere from 25% to 43% of patients tested positive this week for the coronavirus, according to daily numbers provided by the hospitals. In a few cases, the main reason for hospitalization was something other than COVID-19. It is also worth noting that the vast majority — in some cases 75% of COVID patients — reported that they are unvaccinated.

Within Mass General Brigham, the state’s largest hospital network, one daily census taken this week found 30% of COVID patients were vaccinated, 70% were not. In the network's ICUs, 22% were vaccinated, 78% were not.

Among patients at Beth Israel Lahey Health, the state’s second largest hospital system, a recent daily count found 43% of COVID patients were vaccinated, 57% were not. In ICUs, it was 27% vaccinated and 73% not.

“Here we are in one of the most vaccinated states in the country dealing with another surge of COVID,” said Dr. Eric Dickson, president and CEO of UMass Memorial Health, where a daily survey taken this week found 40% of COVID patients had been vaccinated, so had 25% in the ICU.

“The only way that could really happen is if there’s waning immunity from the vaccines that most of us received last year, and that’s clearly happening,” Dickson said.

Hospitals have not done a thorough assessment of the types of vaccinated patients who are hospitalized, but Dr. Erica Shenoy, the associate chief of infection control at Mass General, says patients whose immune systems are weakened by cancer treatment or frail elders are still at greater risk for a serious case of COVID-19 even after they are vaccinated.

“We know vaccines are very effective at preventing hospitalization and death, but they’re not 100%,” said Shenoy. “The benefits are very, very clear. I can’t stress that enough.”

Ellie Murray, an assistant professor of epidemiology at Boston University School of Public Health, says the math helps explain why the percentage of vaccinated patients in the hospital is rising — there are just many fewer unvaccinated people in the state. In Massachusetts, 87% of residents, including children, have had at least one shot, and 72% are fully vaccinated. Murray says serious illness is still much more likely for residents who have not been jabbed.

“Despite fewer than 13% of adult Massachusetts residents being completely unvaccinated, the unvaccinated individuals make up 57-75% of hospitalized COVID cases,” Murray said in an emailed exchange. “When viewed from that perspective we can see that unvaccinated people are much more at risk of being hospitalized from COVID than vaccinated people.”

And they face a higher risk of landing in an ICU. At Tufts Medical Center, 25% of COVID patients are vaccinated. None are in an ICU. At Boston Medical Center, 32% of COVID patients are vaccinated, and just one is the ICU.

Dickson, at UMass Memorial, says the hospital numbers show a need for increased vigilance: more vaccinations, boosters, masks indoors (he recommends a KN95), limited time in large crowds and testing at the first sign of symptoms.

“Every single one of us has a role we can play in stopping the spread of this horrible disease,” Dickson said.

This article was originally published on December 10, 2021.


Martha Bebinger Reporter
Martha Bebinger covers health care and other general assignments for WBUR.



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