COVID-19 is rising again. How effective was the vaccine? How severe is this strain?

Unlike the flu, which tends to peak in the winter months, COVID-19 can start to spike in late summer and early fall as past years have taught. Over the past month, COVID hospital visits have begun to increase again.

However, the cases are much less deadly than in the first years of the pandemic. Some of the new strains, like JN.1, are likely more contagious but less severe than previous versions.

Still, more than 1,600 Hoosiers a week visited emergency rooms with COVID-19 with COVID-19 symptoms in July, an increase from the 800 a week seeking care in June, according to the Indiana Department of Health. The number of Hoosiers hospitalized for COVID-19 increased to more than a hundred a week, an increase from the 30 or so a week who were getting hospitalized in early summer.

The wide use of vaccines and previous infections have built more immunity among Americans so the virus isn't as deadly as it had been in 2020 and 2021, said Brian Edward Dixon, a public health researcher at Regenstrief Institute.

How effective is the vaccine?

The last COVID-19 booster shot, which is becoming an annual shot as the virus changes, is about 50% effective.

That means the vaccine cuts the chances of getting seriously sick with COVID-19 by about half, Dixon said. That's about comparable with the flu vaccine.

The COVID-19 vaccine is expected to be updated for the 2024-2025 season, to better match the changing strains. The new version will be available later this year.

How does COVID-19 compare to the flu?

While the flu circulates in the winter months in the United States, typically from about October to May, COVID-19 doesn't seem to have the same pattern.

COVID-19 tends to peak in the winter months, but also has spiked in the fall and spring since it first emerged in the United States in 2020.

While COVID-19 has become less deadly since then, it's still about twice as deadly as the flu, Dixon said.

What are the symptoms?

COVID-19 symptoms can include fever, chills, cough, shortness of breath, sore throat, congestion, loss of taste or smell, fatigue, muscle or body aches, headaches, nausea of vomiting, according to the U.S. Centers for Disease Control and Prevention.

Binghui Huang can be reached at 317-385-1595 and Bhuang@gannett.com

This article originally appeared on Indianapolis Star: COVID-19 rises across U.S. Here's what to know.