SAN DIEGO — A new COVID-19 subvariant known as omicron BA.2 is beginning to become more present in the U.S., making up about 25 to 30% of current cases.

“Let’s not be surprised,” said Dr. Christian Ramers, an infectious disease expert and chief of population health at Family Health Centers of San Diego. “Let’s not forget that COVID is real and still is with us. It’s definitely not behind us.”

IRamers says this variant likely may be responsible for the current surges happening in Asia and western Europe. It’s inching toward becoming the dominant strain in the U.S., especially in the Northeast and the West.

“Does seem to be taking over and it also does seem to be a little more infectious,” he said. “It’s about 30 to 40% more infectious than omicron, which is more infectious than delta, which was more infectious than the original strain.”

Ramers notes cases are trending upward in San Diego County with wastewater monitoring also showing more presence of the virus in the community.

However, he believes we are in a much better spot than two years ago.

“We have relatively good vaccination rates,” he said. “We have a lot of people that have already been infected and have some natural immunity, that will help them. Of course, the best immunity is having natural immunity, plus vaccine.”

This latest variant comes as the idea of a fourth dose of the vaccine is being discussed. Both Pfizer and Moderna are now petitioning the FDA for approval of a fourth shot. Pfizer’s request is for those 65 and older, with Moderna’s potentially applying for everyone 18 and older.

“Even from natural infection or from immunity from a vaccine the immunity does wane. Viruses tend to really surge during the winter, the open question is whether people’s immunity will last that long,” he said.

Ramer says for that reason, another dose is reasonable in his professional opinion.