More Vaccinations Needed to Reach Herd Immunity and Stop the Spread of COVID-19

Because people who have been vaccinated against coronavirus can still carry and spread it, health experts say more people need to receive the COVID-19 vaccine to achieve herd immunity and keep it from transmitting

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With a few breakthrough COVID-19 cases being reported after people get their vaccinations, public health experts in Massachusetts and nationwide are urging everyone to take precautions until the state achieves herd immunity.

Gunnar Consol, a senior at Plymouth State University, could not believe it when he tested positive three weeks after he received the single shot Johnson & Johnson vaccine.



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"I was more confused than surprised, but I was surprised, nonetheless," Consol said. "They did tell me it was rare. I was one of three in the whole state."

Consol said he is thankful his symptoms were mild because he had already had the vaccine, but experts warn more cases like his are bound to happen until more people are vaccinated.

"I expect to see more of these little outbreaks," said Dr. Michael Misialek, the associate chair of pathology at Newton-Wellesley Hospital.

NBC10 Boston asked Misialek to weigh in on the recent study from the CDC that shows how one unvaccinated worker set off an outbreak at a nursing home in Kentucky where most of the residents were vaccinated.

"It underscores the importance of getting and immunizing as much of the population as possible so that we can reach so-called herd immunity," Misialek said.

To achieve herd immunity and return to pre-pandemic life, 70% of the population has to be protected against the virus. Gov. Charlie Baker has said that will happen when Massachusetts fully vaccinates 4.1 million people. The state is currently about halfway there, and experts say it is imperative for everyone to keep wearing masks and practicing social distancing until then.

"If you have the chance to get the vaccine, do not hold back. It saved me from having a worse case, and the more people who are vaccinated, the less sources we have for COVID to spread," Consol said.

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