The Omicron variant has spread through much of the United States, and Covid cases have been declining locally and statewide.

But did you know that there's a subvariant of Omicron still spreading? (Sigh.)

The highly contagious subvariant is called BA.2 and is known as the "stealth" variant around the world because it was not as well-reported. Now it accounts for a quarter of Covid-19 cases in the United States, and is causing lockdowns in cities like Beijing.

This subvariant has been around since Omicron was first reported in November 2021. The original strain, BA.1, was the cause of the surge in cases late last year. This subvariant, however, is causing a spike in new cases in countries like Denmark, the Philippines and South Africa. Will it pose a threat to the United States, Florida and Sarasota-Manatee?

Here's what we know so far.

BA.2 will not likely cause a U.S. surge.

Since February, BA.2 has been the dominant strain of Covid-19 worldwide. The number of BA.2 cases in the United States jumped from one to 11 percent in early March, and—according to the New York Times—experts warn that another surge in the U.S. may be "imminent" since the subvariant is spreading so rapidly in Europe. (Past surges there have generally been a preview for what's to come in the U.S.)

BA.2 is more transmissible than original Omicron. But existing vaccines work well against it.

While scientists think that BA.2 is even easier to contract than previous mutations of Omicron, current vaccines are still found to provide the greatest protection against severe disease, hospitalization and death, according to a New York study. This is especially true for those who have received the initial two doses of a Covid-19 vaccine plus a booster.

If you've already contracted Omicron, you might be able to fight off BA.2 better.

Studies have found that the BA.2 subvariant is vulnerable to antibodies made by the immune system from a previous Omicron infection. This is because Omicron has mutations that change the virus's surface, making it hard for antibodies to attach to it.

The World Health Organization made an official statement saying that infection with Omicron's original strain (BA.1) provides strong protection against BA.2.

Monoclonal antibody treatments are ineffective against BA.2, but there are other treatment options available.

The New England Journal of Medicine has reported that if you contract BA.2, monoclonal antibody treatments will not work (the subvariant is able to evade it). There are some drugs, like Evusheld by Astrazeneca, and antiviral drugs like Paxlovid, molnupiravir and remdesivir, that are highly effective against all Omicron variants, however.

Where is BA.2 in the United States now?

Right now, the majority of BA.2 is located in the Northeast region of the United States, like New York and New Jersey, according to the CDC's "Nowcast." The report predicts 39 percent of cases in these states are BA.2 and 38.6 percent of cases in New England are BA.2.

For a list of vaccination and Covid-19 testing sites in Sarasota-Manatee, click here.