While last week’s announcement of the state’s first known case of a COVID-19 variant wasn’t surprising, it shouldn’t be taken lightly, says a local infectious-disease expert.

“I do not think that we should let this one go as if this is something routine. We should be concerned,” said Dr. Aalok Khole, an infectious-disease physician at Cheshire Medical Center in Keene.

The B.1.1.7 variant — a mutation in the COVID-19 genome, which was first detected in the United Kingdom — is thought to be more contagious, Khole explained, which could increase the risk of infections, hospitalizations and deaths.

State health officials have released few details about New Hampshire’s confirmed B.1.1.7 case, other than to say Friday that it was diagnosed in a Hillsborough County adult.

This person had contact with someone who was diagnosed with COVID-19 after international travel, according to the N.H. Department of Health and Human Services.

The B.1.1.7 variant has been detected in about 40 states, including Maine and Massachusetts, according to the Centers for Disease Control and Prevention.

And while this is its first diagnosed case in New Hampshire, Khole said there could be others that have yet to be reported.

Those who have already received the full vaccination dose need to continue masking, physically distancing, washing their hands properly and traveling only when necessary, he said.

According to the CDC, this is because more research is needed to understand the vaccine’s abilities, such as whether or not it prevents transmission in addition to protecting people from the disease. Other factors, such as how many people get vaccinated and community transmission rates, are also important to consider before easing safety protocols, the agency’s website says.

“If you’ve been vaccinated and you are two weeks out from your [last] dose, we are not giving people a clean check to go on with their lives for this reason,” Khole said.

Dr. William Schaffner, a professor of medicine in the Division of Infectious Diseases at Vanderbilt University in Tennessee, echoed Khole that the variant is worrisome.

“We’re all concerned about the variants,” said Schaffner, who is also a professor of preventive medicine. “Every virus that is more contagious is a concern because it will more readily [infect] more people and ... it could reverse the current trend and once again cause an upsurge.”

And as Khole did, Schaffner stressed the need for people to continue implementing safety protocols.

“They sound tedious,” he said of these precautions, “and we all have COVID fatigue, but they work, and are more important now than ever with this new variant.”

Both vaccines approved by the Food and Drug Administration — one by Pfizer BioNTech, the other by Moderna — have about a 95 percent efficacy rate against the standard COVID-19 strain.

Against the B.1.1.7 variant, the vaccine’s efficacy may go down, meaning that it wouldn’t prevent as many infections, according to Khole. However, he added that the vaccine would still lead to people having less severe cases than they would without a vaccine.

“When you take things into perspective, like the flu vaccine for example, [for] years and years we’ve been OK when the [vaccine] efficacy rates are anywhere between 40 to 60 percent,” Khole said. “So if the 95 percent has led people to believe that that’s gold standard, and anything less than that is not, that shouldn’t be the case.”

B.1.1.7 and the standard novel coronavirus can cause severe complications, including death. And more hospitalizations could lead to overwhelmed facilities across the state, according to Khole.

Cheshire Medical has seen a dip in hospitalized COVID-19 patients over the past two weeks, with fewer new coronavirus cases reported statewide.

As of Monday, 125 people were in New Hampshire hospitals for the viral disease, and 1,135 people had died from complications of it.

“But again, we’re not out of the woods,” Khole said. “We are keeping a close eye on this.”

Olivia Belanger can be reached at 352-1234, extension 1439, or Follow her on Twitter @OBelangerKS.