Omicron can evade the protection initial vaccines give, but boosters increase efficacy and better protect against the newest variant of concern, Dr. Anthony Fauci said Sunday.

       "If you want to be optimally protected, absolutely get a booster,” Fauci told ABC's "This Week" anchor George Stephanopoulos.

       The omicron variant was discovered in South Africa last month and has been deemed a "variant of interest" by experts. Early anecdotal data has shown that most who contract the new variant experience mild illness, but the main consensus among experts is that it's too early to tell what the long term impacts will be.

       No matter how mild omicron may be, the national average seven-day COVID-19 case rate has increased 12% and hospitalizations have gone up 11% across the country, according to ABC’s COVID-19 Tracker.

       In New York, vaccination rates per 100,000 people have gone up 68% over the last seven days, but the cases have jumped.

       New York Gov. Kathy Hochul said a statewide mask mandate will be implemented Monday. The mandate requires that masks are worn indoors in public places and businesses, unless one shows proof of vaccination.

       This is a developing news story. Please check back for updates.