Medical Experts Urge Caution Between Vaccine Doses

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Connecticut residents 16 and older are now eligible to register for the COVID-19 vaccine. Once you get the first dose, your immune system starts building protection.

“That starts happening approximately a couple of weeks after the first dose,” said Dr. Saad Omer director of Yale Institute for Global Health.

Omer says during that period, some studies show there’s as much as 80% protection between the first and second dose. Pfizer reports that could be as soon as 12 days after the initial vaccination.

“Even after one dose there seems to be increasing levels of protection, but that protection is further enhanced after the second dose,” said Omer.

The data comes from a new CDC study this week that tracked nearly 4,000 US healthcare workers and first responders between doses of the M-RNA vaccines. They were 80% effective after the first dose and 90% after the second.

“It appears the vaccinations are also protecting against asymptomatic infection which is also very important,” said Dr. Manisha Juthani of the Yale School of Medicine. She says that’s because it shows the vaccine is working against unknown cases of COVID-19.

She also says the key to this study is that it’s among frontline workers who follow COVID-19 prevention protocol.

“These are people that in general are mask wearing and doing what they’re supposed to do,” said Juthani. “This is not people gathering at parties with masks off.”

So, while you may be tempted to throw caution to the wind after your first or second dose, experts say don’t do it. With cases on the rise, it’s still possible to be infected even after you’re fully vaccinated.

Pfizer and Moderna both report effectiveness of about 95% after a second dose, and Johnson & Johnson reports 85% effectiveness. That leaves a small percentage of possibly contracting COVID-19.

“Some of the people I have seen in the hospital are people who come in between dose one and dose two,” said Juthani. “Many people have let down their guard because they’ve heard that vaccination gives you some protection.”

An infection after the first dose will delay getting a second, so Summer McGee, dean of the University of New Haven's School of Health Sciences, says you should plan for the next six weeks.

“That is a really critical time when you want to be absolutely sure you’re taking all of the appropriate precautions and then up to two weeks after that final dose you still don’t have your full immune response yet,” said McGee.

Omer says with COVID cases still rising it’s important for people to be aware of the risks and stay safe.

“The first couple of weeks you should do exactly what you were doing before,” said Omer. “Wait a week or two after your second dose and then start complying with CDC guidelines for vaccinated people.”

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