The CDC reports that the JN.1 subvariant of the coronavirus is rapidly spreading in the United States, causing approximately 20% of new Covid-19 infections and dominating in the Northeast, where it accounts for about a third of new cases. JN.1 is a descendant of BA.2.86, also known as Pirola, which garnered attention due to significant changes in its spike proteins. While BA.2.86 did not lead to a major surge, JN.1 has emerged as the fastest-growing strain, with its prevalence more than doubling in the U.S. between late November and mid-December.
Unlike its predecessor, JN.1 only has one change to its spike protein, making it a fitter and faster virus. Experts believe it is benefiting from holiday travel and waning immunity, particularly as some individuals have not opted for the latest round of Covid-19 vaccinations. The CDC warns of a 51% increase in hospitalizations for Covid-19 in the past four weeks, along with rising rates of flu and RSV, which could strain hospital capacity.
The mutation in JN.1’s spike protein may reduce the effectiveness of antibodies by approximately twofold, potentially leading to another wave of infections. The subvariant is rapidly spreading in various countries, including those in Europe, Australia, Asia, and Canada. The CDC urges healthcare professionals to intensify vaccination efforts, emphasizing that it is not too late to benefit from Covid-19 shots. Despite concerns, a recent study from Columbia University indicates that the current Covid-19 vaccine provides good protection against JN.1 and its precursors, supporting the recommendation for widespread vaccination. The World Health Organization also endorses upgraded Covid-19 vaccines for their broad protection against various variants. However, there is concern that fewer people are getting booster shots and antiviral treatments, which could mitigate the impact of the virus.