Doctors explain why the delta variant is worst they have seen

The delta strain of COVID-19 is putting healthcare workers to the test, Florida infectious disease experts explain why the mutation is a game-changer in the pandemic.

"It's about six times more infectious than the original strain, making it and put it at a level of infectivity now and pretty much the same as whooping cough or smallpox. And smallpox is like a highly, highly infectious virus," said Dr. Thomas Unnasch, an epidemiologist with USF Health.

Unnasch said even some symptoms are different, like more nasal congestion and feelings of allergies and less loss of taste and smell. The virus also now multiplies at much higher levels, scientists said. UF Health Chief Hospital epidemiologist Dr. Nicole Iovine shared what that means for your body.

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"In vaccinated people, that viral level dropped pretty quickly in a few days. And that's very different from what happens in unvaccinated people where it stays high for days or even weeks," said Iovine. "And because of that, that's why unvaccinated people are getting really sick and they go to the hospital and dying."

Doctors said people who had covid-19 should not rely on those antibodies.

"So we're seeing a fairly large number of people coming through now with significant symptoms, perhaps turning up in the hospital who have COVID the second time around. So they thought they had it. They thought they were immune, and they thought everything was fine. They didn't need to get vaccinated, and they've been hit again," said Unnasch.

Scientists said the delta variant won’t be the final act as long as there are a lot of unvaccinated people.

"This is definitely the worst one that we've had yet, absolutely. And I don't mean to be alarmist, but as long as there are unvaccinated people, the virus will continue to mutate," said Iovine.

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Doctors said another mutation is avoidable with masks and vaccines. They said those are the best protection, and it’s up to the public to stop the spread.