Yet another COVID-19 subvariant is spreading steadily throughout Maine as hospitalizations continue to ebb and flow in the virus’s latest show of unpredictability.

This latest strain — a subvariant of the omicron variant called BA.5 — is now the dominant strain in the nation, according to estimates released by the U.S. Centers for Disease Control and Prevention earlier this month.

While the CDC said BA.5 does not appear to cause more severe illness compared to other variants, it does appear to be much more transmissible.

Researchers in South Africa, which experienced a surge in BA.5-related cases in the spring, found that the virus spread quickly despite the approximately 98% of the population that had some antibodies, either from vaccination or previous infections, or both.

Cases also spread quickly in some European countries earlier this year, even though the initial omicron waves swept across the continent only a few months earlier.

The more people that are infected, the more people that may end up hospitalized with COVID. Those patients may be there for COVID-related symptoms or for something else but happen to be COVID-positive as well.

Hospital leaders in Maine said that high volumes of COVID patients — who need to be isolated from other patients — regardless of the severity of their disease, can present logistical challenges and stress on their systems.

As of the latest genomic sequencing report from the Maine CDC, omicron accounted for 100% of all samples taken in June and BA.5 accounted for about 25% of all samples.

Hospitalizations statewide have been on the rise over the past few weeks: 140 people were hospitalized with COVID-19 as of Wednesday, a 23% increase compared to one week prior and 12% more than two weeks ago.

There was an average of 135 patients hospitalized every day for the week ending Wednesday.

Central Maine Medical Center in Lewiston had eight COVID patients on Wednesday, nearly three times as many compared to one week earlier.

The latest hospitalization numbers were not immediately available from St. Mary’s Regional Medical Center, also in Lewiston.

And although the omicron subvariants have shown an ability to evade antibodies, data from the U.S. CDC continues to show that getting vaccinated remains the best protection against severe illness or death.

As of the latest estimates, in May unvaccinated people 5 years and older were at twice the risk of testing positive for COVID compared to people with at least their primary vaccination series, and at six times the risk of dying.

For people 50 years and older, those who were unvaccinated were at four times the risk of dying compared to those with at least one booster and 29 times the risk of dying compared to those with at least two booster shots.