Winter COVID Wave 2024: Understanding the 3 Key Aspects

1. Prevalence of the JN.1 Variant and Its Impact

The JN.1 variant of COVID-19 is currently the most prevalent globally and is dominating in regions like Europe and Asia.

As of December 2023, it accounted for approximately 66% of the COVID-19 cases detected through wastewater surveillance in the U.S. Despite increased hospitalizations and deaths due to this variant, these numbers are still significantly lower than previous years, indicating a change in the relationship between infection levels and illness severity.

This change is attributed to greater immune protection levels provided by vaccines, prior infections, or both. Over 97% of people now have some form of immunity against SARS-CoV-2. However, only 19% of adults in the U.S. have received the updated COVID-19 vaccine as of December 30, 2023, which is concerning, particularly for high-risk groups like older adults​​.

2. Current Trends in Hospitalizations and Vaccinations

COVID-19 hospitalizations increased by 20.4% in the week ending December 30, 2023, and deaths went up by 12.5%. Despite these increases, the severity of illness is much lower than in previous waves, mainly due to widespread immunity.

However, the lower vaccination rates, especially among children and older adults, remain a concern. It’s important for individuals to get the updated COVID-19 vaccine to increase protection against the JN.1 variant and other strains​​.

3. Outlook for the Respiratory Disease Season

Experts anticipate a return to pre-pandemic patterns for respiratory viruses, including COVID-19. Last year’s flu season was early but not significantly worse than usual. With COVID-19 hospitalizations and deaths at all-time lows and a general return to pre-pandemic behaviors, a similar pattern is expected this year.

However, there’s still a possibility of an early flu season, making it advisable for people to get flu shots in September or October. Additionally, a new antibody for RSV called nirsevimab has been approved, providing longer-lasting protection against RSV, especially for infants​​.


As the winter COVID wave of 2024 unfolds, the key factors to keep in mind are the prevalence of the JN.1 variant, current trends in hospitalizations and vaccinations, and the overall outlook for respiratory diseases.

Continued vigilance and adherence to public health recommendations, including vaccination and boosters, remain crucial in managing the impact of COVID-19 and other respiratory viruses during this season.