Much of the pandemic-related news in recent days has focused on the rise of the omicron variant, which has created yet another layer of uncertainly to the pandemic. Here’s what we know so far.

What is omicron?

Omicron is the latest variant of concern of the novel coronavirus that spawned a nearly two-year pandemic.

The variant was first detected in mid-November by researchers in South Africa and was declared an official variant of concern on Nov. 24 by the World Health Organization.

Although the variant was detected in South Africa, it could have emerged anywhere, and in a short period it has spread across the globe.

The first U.S. case was detected on Dec. 1, and in less than three weeks it became the dominant strain, supplanting the delta variant.

Why is omicron such a major concern?

The variant is highly transmissible, even more so than delta, which already was far more transmissible than the original coronavirus strain. The reason it’s so highly transmissible, according to researchers, is that its spike protein is more effective at attaching to human cells.

The U.S. Centers for Disease Control and Prevention has estimated that as of this week, the omicron variant accounts for three out of every four new cases nationwide.

Why aren’t there more cases in Maine?

Officially, the state has confirmed five cases. But officials believe there are far more than that.

Only a relatively small number of samples from infected people are screened for omicron, and it takes time for genomic sequencing tests to determine whether they match the omicron variant, so there is a lag.

“Though it is not the dominant variant in Maine right now, it may very well become the dominant variant over the next few weeks,” Maine CDC Director Dr. Nirav Shah said. “The bottom line with omicron, based on what we know, is: It’s concerning. Its greater contagiousness means that it is a new variant that we have to reckon with.”

Shah said Maine people need to take omicron seriously.

“Recent data suggest that it will cause a spike in cases, as it has done in other countries around the globe. And that spike may increase the strain on hospitals,” he said.

Does omicron lead to more severe symptoms?

There is some research that the omicron variant causes milder symptoms than the delta strain. The New York Times reported Wednesday that teams of scientists in South Africa, Scotland and England each has found that omicron infections more often result in mild illness than earlier variants.

That research is encouraging but not conclusive. And even if the variant proves milder, many people could get sick or die, especially if they have other health conditions, simple because of how contagious the variant is.

“There is some chatter out there that omicron might be mild. The bottom line is, we don’t know,” Shah said. “Mild compared to what? Mild for whom? There are still a lot of scientific questions out there that need to be answered before we can make any definitive statements about its severity.”

What is Maine doing to determine whether omicron is spreading?

In order to determine whether a case of COVID-19 is a specific variant, a sample from a patient who tested positive must be subjected to something called genomic sequencing. The Maine CDC does some sequencing at its lab, but the bulk of that work is done by a team of researchers at The Jackson Laboratory in Bar Harbor.

Ryan Tewhey, who leads that team, said this week that it conducts sequencing for the state from Tuesday through Friday and then submits a report. The most recent report, from Monday, showed five confirmed cases, but Tewhey said it’s important to remember that those cases are up to two weeks old.

“This week’s snapshot will be very informative and should tell us what trajectory the state is on,” he said. The Maine CDC is not expected to release those results until next week.

Generally speaking, Maine has lagged behind other states in the appearance of new variants.

Do vaccines protect against the omicron variant?

This, too, is still being studied, but experts believe that people who are fully vaccinated and especially those who have received booster shots, have a strong level of protection against omicron.

That doesn’t mean fully vaccinated and boosted individuals are necessarily 100 percent immune. There will still be breakthrough cases, just as there have been with the delta variant, but the risk of serious illness or death is drastically lower.

“What we do know is that many of the tried-and-true elements of our response so far are effective against omicron,” Shah said. “For example, vaccines, and in particular boosters, continue to be among the best defenses against omicron.”

Shah also said mask-wearing indoors is perhaps even more important now than ever given the ease with which omicron spreads.

What can families do to gather safely for the holiday in light of omicron?

Most families in Maine likely expected this holiday season to be a return to normal after 21 angst-filled months. But that won’t be the reality for most.

Health officials said the best thing people can do to stay safe when they gather is to make sure everyone is fully vaccinated and, where eligible, boosted. Smaller groups are preferable to large gatherings and masks are advised, especially if there are unvaccinated people in attendance or people at high risk.

Finally, people can take a rapid COVID-19 test, if they are able to find one, ahead of any gathering. The tests are sold over the counter in pharmacies, but supplies have been limited and it may require shopping around or checking websites to see who has them in stock.

The Biden administration announced this week that it plans to make 500 million rapid tests available to Americans through the mail, but that won’t happen until after the holiday season. The administration has said it will set up a website for people to request the free test kits, but details have not been announced.