SAN DIEGO — County officials said the first two cases of a coronavirus variant from Brazil have been detected in San Diego, one in a resident and one in a non-resident.

The news came in a briefing Wednesday. Dr. Eric McDonald, a leading county public health official, said the P.1 variant — first discovered in Japan in four travelers from Brazil — is listed as a “variant of concern” by the Centers for Disease Control.

McDonald said this is due to evidence that some vaccines may be less effective against it, though he added that there is not currently evidence that the variant is more transmissible or severe. It is possible, however, that someone who’s already had COVID-19 could be sickened again by the strain, he said.

Neither of the cases detected in San Diego led to hospitalization and neither person had been vaccinated.

“This virus evolves all the time,” McDonald told reporters. “This is one of the virus’ variants that’s been detected in the world that’s now been detected for the first time in San Diego and we just need to be very vigilant of all the things that we’re already doing.”

Asked how the news should impact residents’ vaccination plans, the doctor said not at all: “The message on the vaccine is that you should get it when it’s your turn. That message has not changed.”

It is possible, however, that booster shots will eventually become available for certain variants in the future, he added.

Dr. Phillip Febbo, chief medical officer with Illumina, said the Brazilian variant caused a peak in COVID cases in Brazil, which brings up a broader concern.

“The concerning issue there is some people who already had the virus before got sick again,” Febbo said.

He said that’s because the Brazilian strain has the same variation within it found in the South African variant, essentially allowing those who have already had COVID to catch the Brazilian strain.

He also said some vaccines may be less effective, but it’s too early to tell which ones.

Febbo said Moderna and Pfizer are working on bolster vaccines for the future if needed.

“They’re doing clinical studies on boosters that include variants including E484K, which is the troublesome one that the P.1 variant has,” he said.

Other than the household contacts of the county resident, McDonald said, contact tracing did not reveal concerns about widespread exposure locally. The non-resident had traveled internationally, and the county went through the CDC to notify relevant authorities, he added.

The San Diego resident’s case was revealed through a CDC program that tests certain samples for variants. The other person’s case was detected at a local public health lab, McDonald said. They were not thought to be related.

As of Wednesday, 61 cases of the new strain had been reported in the United States, according to the CDC.

You can read more about COVID-19 variants of concerns on the CDC’s website.