This alert aims to raise awareness of current guidance around the prevention and treatment of respiratory pathogens as we begin the 2024-2025 respiratory virus season. In addition, we wish to direct providers to local and national data sources for following disease activity for COVID-19, influenza and Respiratory Syncytial Virus (RSV).

Current surveillance data indicates that COVID-19 cases continue to decline and both influenza and Respiratory RSV activity are low in Orange County and nationally. The CDC forecasts that the 2024-2025 season will have similar or lower respiratory hospitalizations than the prior season.

The 2024-2025 season brings updated COVID-19 and influenza vaccines and expanded availability of RSV vaccines and monoclonal antibody products.

Influenza A (H5N1) [avian influenza] detections in dairy cows have been detected in multiple (14 to date) states, including California dairies. Cases of avian influenza have occurred in a small number of people directly exposed to infected animals, including California. One confirmed case of avian influenza has been identified in Missouri without any known animal exposure. This case is still being investigated and CDC is monitoring that situation closely. The CDC's current assessment is that the risk of avian influenza to the general public is low.

COVID-19

• Orange County COVID-19 activity is posted weekly at https://www.ochealthinfo.com/covid. National and state COVID-19 data can be accessed at the CDC’s Respiratory Illness Data Channel.
• The 2024-2025 COVID-19 vaccines approved for use by the FDA include two mRNA products (manufacturers Moderna and Pfizer) and the protein-based vaccine from Novavax.
• The CDC’s updated Interim Clinical Considerations for the Use of COVID-19 Vaccines provide comprehensive guidance.
• There continue to be effective treatments [Nirmatrelvir with Ritonavir (Paxlovid), Veklury (remdesivir), & Molnupiravir (Lagevrio)] which are recommended for those at risk for more severe disease, including the elderly, those with underlying medical conditions, and the unvaccinated.
• Providers are NOT required to report cases of COVID-19 to OCHCA.

Influenza 

• Orange County influenza activity is posted weekly at https://www.ochealthinfo.com/influenza. National and state influenza data can be accessed at the CDC’s Respiratory Illness Data Channel.
• For the 2024-2025 season, all influenza vaccines will be trivalent with components consisting of an Influenza A (H1N1pdm), influenza A (H3N2), and Influenza B (Victoria-lineage).
• Vaccination is recommended for all individuals 6 months and older.
• The full 2024-2025 recommendations from the Advisory Committee on Immunization Practices (ACIP) are available here.
• The list of available vaccines and formulations is available here.
• Current guidance on the treatment of influenza is available at Influenza Antiviral Medications: Summary for Clinicians.
• The current assessment is that the risk of avian influenza is low.  
• There are no FDA licensed commercial dairies in Orange County.
• The CDC has released Interim Guidance on the Use of Antiviral Medications for Treatment of Human Infections with Novel Influenza A Viruses Associated with Severe Human Disease. 
• Testing for novel influenza viruses, including H5N1, is available through the Orange County Public Health Laboratory (OC PHL) by reaching out to OCHCA Communicable Disease Control Division at 714-834-8180.

RSV

• Orange County RSV activity is posted weekly at https://www.ochealthinfo.com/rsv. National and state RSV data can be accessed at the CDC’s Respiratory Illness Data Channel.
• All adults 75 years and older and adults 60-74 years with risk factors for severe RSV are recommended to receive a dose of RSV vaccine. The current guidance is that this is a one-time dose and those vaccinated previously do not need additional doses. The full guidance on the use of RSV vaccine for older adults is available here.
• Pregnant people are recommended to receive the RSV vaccine (Abrysvo, Pfizer) during weeks 32 through 36 of their pregnancy during the months of September through January to protect their newborns from severe RSV disease. The full guidance on the use of this RSV vaccine in pregnancy is available here.
• Nirsevimab (Beyfortus) is recommended for protection from RSV for infants and young children. ACIP guidance on the use of nirsevimab is available here.

CDPH Health Advisory Preparation for Respiratory Virus Season (COVID-19, Influenza and RSV)

Providers with questions or to report confirmed and probable cases of MPX should contact OCHCA Communicable Disease Control Division at 714-834-8180.