JN.1 variant makes up a majority of COVID cases in the US. Here's what to know

• The JN.1 variant has become the predominant COVID-19 strain in the United States.
• Scientists are monitoring the variant's potential impact on vaccine effectiveness and transmissibility.
• JN.1 is a subvariant of the Delta variant and contains some mutations of concern.
• Variants like JN.1 underscore the importance of continued vigilance and vaccination efforts.
• Experts are studying whether JN.1 could lead to increased COVID-19 cases in the coming months.