XBB.1.16, also known as Arcturus, is a new omicron subvariant of the COVID-19 virus that is spreading in the U.S.

It has mutations that make it more transmissible and able to evade some immunity, and doctors have reported anecdotal evidence of it causing unusual symptoms such as fever and conjunctivitis.

It is recommended that people stay up to date on their COVID-19 vaccinations to protect against the virus, and, in the future, it is possible that annual boosters may become a norm.