Here’s what you should know about the delta variant:

What is the delta variant?

Like all viruses, COVID-19 has changed over time, resulting in different variants. The delta is one of four variants listed as a variant by the Centers for Disease Control and Prevention and WHO. The other three variants of concern are alpha, beta and gamma.

The delta variant was first documented in India in October, according to WHO. In the following months, it’s spread to nearly 100 countries, including the U.S., Mexico, Canada, the U.K., Australia, China and Russia.

WHO designated the delta variant as a variant of concern after receiving evidence that the variant has an increased transmissibility.

Is the delta variant in Ohio?

The state health department reported the delta variant has been detected in Ohio and it is expected to become Ohio’s dominant strain of coronavirus.

From May 23 to June 5, about 1.9% of Ohio’s positive cases were the delta variants, based off genomic sequencing, ODH Chief Medical Officer Bruce Vanderhoff said on July 14. From June 6 to 19 it increased to 15%.

“Delta is moving rapidly to replace B117 or the alpha variant as our dominant form of COVID-19,” he said.

According to the CDC, 80.4% of the cases reported in Region 5, which includes Ohio, Illinois, Indiana, Michigan, Minnesota and Wisconsin, from July 4-17, were of the delta variant. The alpha variant accounted for 11.5% of cases and the gamma variant accounted for 5.3%

On July 26, Vanderhoff said that signs pointed toward the delta variant driving an increase in cases reported in Ohio recently.

Do the vaccines work against the delta variant?

Of the four variants detected in the U.S., delta, alpha, beta and gamma, not one of them is classified as a variant of high consequence. The CDC defines variants of consequence as variants where there is evidence that prevention measures or medical countermeasures, such as vaccines, have reduced effectiveness.

Vanderhoff said that the vaccines approved in the U.S. — Pfizer, Moderna and Johnson & Johnson — all appear to effective against the delta variant and remain the best protection against the virus.

“There are really two ways to protect yourself and others from COVID-19,” he said on July 26. “Vaccination is the best way, but if you choose not to or cannot be vaccinated, masking with layered safety measures is also a very good way to protect yourself and others.”

To get vaccinated against coronavirus, visit https://gettheshot.coronavirus.ohio.gov/.

Do vaccinated people need to wear a mask to protect themselves?

With cases increasing across the country, the CDC announced Tuesday that even vaccinated people should wear masks while in areas with a “high” or “substantial” coronavirus transmission rate.

Local counties meeting that criteria include Butler, Clinton, Greene, Miami, Montgomery and Preble.

Counties with substantial transmission are those reporting 50 to 99.99 cases per 100,000 people in the last seven days. High transmission means a county has reported more than 100 cases.

Los Angeles and St. Louis are two cities that recently decided to mandate masks indoors due to a spike in infections, the Associated Press reported.