CFA's Insights for Respiratory Virus Season

Purpose

CFA is providing insights to support public health planning and response to the fall and winter respiratory virus season. Below, we highlight our current and upcoming products related to respiratory virus season. We will share additional products as the season progresses.

Current Epidemic Growth Status

CFA provides weekly estimates of Rt, the time-varying reproductive number, at the national and state levels to determine the current epidemic growth status. Estimates are currently available for COVID-19 and will resume in the fall for influenza. Rt is a data-driven measure of disease transmission. Rt can tell us whether infections are growing, declining, or remaining stable, and can help public health practitioners prepare and respond to these viruses – read more about Rt and how we calculate it.

Map of the United States showing each state colored by its epidemic growth status category.
Example of the Epidemic Growth Status tool. Visit the page to view the current epidemic growth status.

Respiratory Disease Season Outlook

CFA led development of the 2024-2025 CDC respiratory disease season outlook to provide decision-makers information to assist with public health preparedness, including planning for potential surges in hospital demand. CDC expects the upcoming fall and winter respiratory disease season will likely have a similar or lower number of combined peak hospitalizations due to COVID-19, influenza, and RSV compared to last season. CDC will monitor respiratory disease activity and will update this assessment throughout the fall and winter.

Bar chart with past and anticipated peak hospitalization rates for 17-18, 22-23, 23-24, 24-25 respiratory seasons.
Experts believe there’s a roughly 80% chance that the hospitalization burden for COVID-19, influenza, and RSV combined at their peak during the 2024-25 season will be similar to or lower than last season.

How scenario modeling can inform decision-making

CFA has developed scenario modeling capability that allows decision-makers to examine a range of possible outcomes under different assumptions about the future, providing insights for addressing specific policy questions and for general preparedness and planning. Read more for an overview of how scenario modeling helped inform CFA's 2024-2025 Respiratory Disease Season Outlook.

Line chart of historic COVID-19 hospitalizations with ribbons for two possible peaks based on different scenario models.
Two possible scenarios for peak COVID-19 hospitalization depending on timing of summer COVID-19 activity and input data source.

COVID-19 Forecasts (coming soon)

Previously, CDC has submitted short-term forecasts of COVID-19 hospital admissions to the COVID-19 Forecast Hub. The COVID-19 Forecast Hub, which is currently paused, receives forecasts from modeling teams from across the country and builds a single ensemble forecast. These ensemble forecasts for COVID-19 hospitalizations have helped public health decision-makers anticipate healthcare burden and prepare for potential COVID-19 surges. One of the forecasts CFA submitted was informed by wastewater data – read more about CFA's wastewater-informed COVID-19 hospital admission forecast. COVID-19 hospitalization forecasts are expected to resume this winter.

Line chart showing daily COVID-19 hospital admissions on the y-axis and Feb to May on the x-axis.
Example of a COVID-19 short-term forecast showing the observed number of COVID-19 hospital admissions in black and an ensemble forecast estimating the future number of COVID-19 hospital admissions in red with shaded prediction intervals.

Respiratory Illnesses Data Channel

CFA provides forecasts and analytics to support CDC's wider preparedness efforts for respiratory virus season. Part of the wider effort includes the Respiratory Illnesses Data Channel, which provides a snapshot of COVID-19, influenza, and RSV activity in your community so that you can protect yourself and others.