The COVID-19 pandemic has lasted nearly two years. In that time, the virus has evolved into a handful of variants. Like Alpha, Beta, Gamma, or Delta. Delta was the dominant variant this past summer. But it was quickly replaced by a new one: Omicron. (Pronounced: OH-muh-kraan.) Like Delta, the World Health Organization and the CDC dubbed Omicron a “variant of concern.” And just weeks after it was first detected, it became the dominant variant in the US — now accounting for more than 98% of daily cases. There are still some details we don’t know about Omicron. But here’s what experts have found so far… What do we know about the Omicron variant? Like all of the other variants that came before it, Omicron gets its name from the Greek alphabet. On Nov. 24, South Africa first flagged the variant. But days later, Dutch health officials said it reached the Netherlands before South Africa first reported it to the world. Meaning: It was spreading in Western Europe much earlier than experts thought. Omicron carries a high number of mutations — more than 50. For context, Delta has around 20. Not good, since these mutations could make it more transmissible and better at evading the body’s immune system. Quick refresh on how variants form: Variants happen when a virus’s genes change or mutate. And it’s actually normal. As the virus spreads, it makes copies of itself. Not all the same instructions make it into the new copy. That’s how we end up with new variants. Research shows that Omicron is two to three times more transmissible than Delta — with Dr. Anthony Fauci calling it “the most transmissible” variant we’ve seen so far. It's also less susceptible to vaccines. Meaning, breakthrough cases or reinfection are more likely. (More on that below.) The good news? Omicron seems to cause less severe illness than other variants. And early research suggests Omicron doesn’t cause as much lung damage as other variants — which may explain the less severe cases. Instead, it centers on the throat. Watch the video below to find out the top three things to know about Omicron, according to Fauci. But Omicron is breaking COVID records left and right. The US has seen a record-high number of COVID-related hospitalizations — including for pediatric cases. There’s also been an average of more than 760,000 new daily cases — tripling the previous record high from January 2021. Dr. Wafaa El-Sadr, director of ICAP at Columbia University and professor of epidemiology and medicine, said that hospitalizations are higher because cases in general are higher. But, it’s critical to look at who is being hospitalized. “We continue to see that there's a much higher rate of hospitalizations with people who are unvaccinated versus people who are vaccinated,” El-Sadr said. “That maintains the value of vaccination.” Reminder: COVID-19 symptoms include a fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, loss of taste or smell, congestion or a runny nose, and sore throat. The CDC says that the most commonly reported ones for Omicron have been cough, fatigue, and congestion or runny nose. Loss of taste or smell appears to be less common. If you're not sure if you've got a cold, COVID, or the flu, this can help. Another reminder: If you test positive, isolate for at least five days — regardless of your vaccination status. If you live with others, stay in a separate room. Don’t share household items (think remote controls and salt shakers). And if you can, use a separate bathroom. Once your quarantine is done, the CDC says you should continue to wear a mask for an additional five days. If you want to calculate your isolation period, day zero = your first day of symptoms. Day one = the first full day after your symptoms developed. Omicron’s arrival has also reignited the convo on vaccine inequity. Since December 2020, rich countries have been buying up shots. But poorer countries are getting left behind. According to Our World in Data, only 9.5% of people in low-income countries have received at least one dose. While 59.4% of people in high-income countries have received at least one dose. WHO Director-General Tedros Adhanom Ghebreyesus said, “Vaccine inequity is a killer of people and jobs, and it undermines a global economic recovery.” Hopefully countries can start sharing the wealth. Like Israel, which donated 1 million vaccines to African countries in December. How effective are vaccines against Omicron? Early data suggests that current FDA-authorized vaccines are 30% to 40% effective at preventing infection, and 70% effective at preventing severe disease. But booster shots appear to be a huge help: Additional research shows that booster shots provide 70% to 75% protection against symptomatic infection. Pfizer and Moderna are developing updated boosters, specifically for Omicron. Pfizer’s could be ready as early as March, but Moderna’s may not be ready until the fall. In the meantime, officials continue urging people to get vaxxed and boosted. “We knew from day one that these vaccines are not 100% protective against infection…What really scares people about COVID is the risk of getting very sick, needing to be hospitalized, or worse,” El-Sadr said. “And the vaccines are decreasing your risk of getting hospitalized or getting very sick with Omicron.” Only 36% of Americans are fully vaxxed and boosted. And there are concerns that the Omicron variant may increase vaccine hesitancy, given the fact that it’s less severe and more likely to evade antibodies than other variants. But El-Sadr emphasized how important vaccines are for preventing serious illness. “A lot of people who are vaccinated have gotten infected. But thankfully you're much more likely to have either no symptoms at all, or mild symptoms, compared to somebody who’s unvaccinated,” she noted. Where has Omicron spread to? In mid-December, the WHO said Omicron had been detected in 89 countries. But that number could be much higher. The first case of the Omicron variant was confirmed on Dec. 1 in the US. Health officials said the person recently returned from a trip to South Africa and was fully vaccinated. Since then, the variant has been ID’d in all 50 states. Amid the surge, previous COVID-era restrictions have made a comeback. Some states have reimposed indoor mask mandates and many school districts have shifted back to remote learning or delayed reopening schools after the holiday season. World leaders are also going on the defensive. Japan and Israel have brought back travel restrictions against all foreigners. The Netherlands currently won’t allow visitors from outside the EU. And many countries are banning unvaccinated travelers or requiring negative COVID tests. Is Omicron impacting travel? The situation is fluid for those with travel plans abroad. Meaning: Prepare for possible changes. Omicron has caused significant staffing issues for airlines around the US, with more and more employees calling in sick. Thousands of holiday travelers experienced flight cancellations — which have continued into January. Meanwhile, the CDC has issued new requirements for people traveling into the US. As of Dec. 6, inbound travelers must show a negative COVID-19 test result within 24 hours of departure. (The prior time frame was 72 hours.) And they have to submit proof of a negative result to the airline before boarding the flight. Those who recently recovered from the virus can provide proof of recovery instead of a negative test. How to Cope With Another COVID-19 Surge As we continue to learn more about Omicron, it’s important to keep perspective. President Biden has said that Omicron is a “cause for concern, not a cause for panic.” Remember, new information on the variant will continue to come in. And could cause health officials to change safety guidelines. So it’s important to keep an open mind and stay updated. With all the uncertainty, there’s no doubt that people are stressed about what’s happening. Here’s some info that can help you out… Check out our resources on keeping your mental health in check and how traumatic events can affect your health If someone in the group chat texts you that they’re positive, get tested. We’ve got info on the different types of COVID-19 testing available. If you aren’t vaxxed and came in close contact with someone who has COVID, quarantine for five days. If you’re fully vaxxed, monitor yourself for symptoms and wear a mask in public for 10 days. If you’re experiencing symptoms, take care of yourself by monitoring how you’re feeling and try to protect others. Rather than take medication advice from TikTok, talk to your doctor about your options. theSkimm The Omicron variant has spread faster than experts predicted — breaking case and hospitalization records. Even with breakthrough cases, vaccines have proven to be worthwhile. But there’s still a lot more to learn about COVID-19’s latest strain. And it’ll take some time before officials have all of the important details. Updated on Jan. 12 to include latest Omicron data and vaccine efficacy. Updated on Dec. 28 to include new CDC isolation guidelines.