The JN.1 variant of Covid-19, now responsible for over 44% of cases in the US, is believed to be more infectious or better at evading immune defenses. It remains uncertain how much this variant will contribute to increased infections or hospital admissions. The prevalence of JN.1 has increased from 21.3% to 44.2% in the past two weeks, particularly in the Northeast region. The CDC confirms that current vaccines, tests, and treatments are effective against JN.1.