PENNSYLVANIA (WHTM) — The delta variant is now the dominant strain of COVID-19 in the United States. Experts worry that the variant is more contagious than previous iterations of the coronavirus, possibly threatening to reverse the progress toward normalcy the country has made in recent months.

“We do know that the delta variant is present in Lancaster County and in Pennsylvania,” Dr. Joseph Kontra, chief of infectious diseases at Penn Medicine Lancaster General Health, said. “Our caseload, in general, is low — very low in Pennsylvania, in fact — which is great news. But I’m concerned that because the variant is here, we may begin to see a rise in cases.”

Researchers are still looking into whether the delta variant causes more severe cases of COVID-19, but its increased infectiousness has clearly caught experts’ attention.

“Instead of one person with COVID infecting two or three people, we probably have one person with COVID infecting four to six,” Dr. John Goldman, infectious disease specialist at UPMC Pinnacle, said. The delta variant has been spreading especially rapidly in places with low vaccination rates, noted Kontra.

Fortunately, the COVID-19 vaccines still seem to be protecting people from serious illness even with the presence of the delta strain.

“What we’ve really found is that the vaccines, even against the delta variant, are extremely effective against having people get very sick, end up in the hospital, or die. And in fact, more than 90% of the people in the hospital right now with COVID haven’t been vaccinated, and 99% of the people who have died haven’t been vaccinated,” Goldman said.

Kontra and Goldman agree that vaccinated individuals have a reduced risk of getting seriously sick from the delta variant as well as the other existing strains of COVID-19.

Unvaccinated individuals may want to revisit previous public health measures like masking and social distancing to stay safe, though, said Kontra.

“If you’re going into a crowded area, you should wear a mask, you should try and social distance, you should wash your hands a lot. Without the vaccine you have to fall back on some basic public health maneuvers, which do provide some protection but are not as good as getting vaccinated,” Kontra said.

The WHO advises everyone, regardless of vaccination status, to continue masking and taking other precautions. This recommendation came just days before Pennsylvania’s mask mandate was lifted.

Kontra said that if Pennsylvania starts to see a rise in coronavirus cases due to the delta variant, people — especially those who are unvaccinated — may want to consider breaking their masks out for public excursions again.

Goldman also encourages unvaccinated individuals to wear masks in public and continue taking other precautions, and he advises other people to consider masking based on their individual risk factors. For example, Goldman said breakthrough infections tend to occur in older individuals or people with suppressed immune systems.

Additionally, Goldman said individuals should consider where they’re going to be when deciding whether or not to mask up. In more crowded indoor places or in areas with a higher rate of infection, individuals may want to wear their masks.

So far, COVID-19 infections are down in Pennsylvania, but Kontra said that could change. “The virus is taking a little bit of time off for the summer. It will be back in the fall,” Kontra said.

“This is an opportunity for us to go out and get vaccinated now so that when the delta [variant] begins to expand in Pennsylvania, as it has done in many, many other states across the country, we will have already become more vaccinated and have it less likely to spread among our population,” Kontra said.