BIRMINGHAM, Ala. (WIAT) — Health officials say the BA.5 COVID-19 subvariant is sweeping the nation. According to the CDC, it makes up about 78% of new cases nationwide. Many states, including Alabama, are dealing with a surge right now.

UAB infectious disease expert Dr. Michael Saag said this variant is smart and extremely contagious.

“This current variant, BA.5, is at least 100 fold, 100 times more infectious than the original SARS-CoV-2 that we saw in December 2019 and January 2020,” Dr. Saag said.

President Joe Biden tested positive for COVID-19 Thursday. He is vaccinated and double boosted but experts said vaccinated people can still get COVID-19. Dr. Saag says people can also have reinfections because of the way the new variants infect the human body.

“The reason for that is variants emerge under selective pressure. It’s Darwin. It’s survival of the fittest and we’re watching that appear in real time before our eyes with this virus and these variants,” Dr. Saag said.

Dr. Saag stressed that experts are still learning about this virus and that we will continue to see new variants as it mutates. He said now is the time to get vaccinated and boosted if you haven’t already,

As immunity tends to weaken over time, Dr. Sagg strongly encourages getting boosted every six months to a year, in addition to wearing masks and social distancing.