Health Advisory: Immunize, Test, and Treat this Upcoming Respiratory Virus Season (Influenza, RSV, and COVID-19) 9/25/2026

​Foreca​st

COVID-19 is currentl​y circulating in California, with influenza seasonal activity starting to increase and RSV seasonal activity expected to increase in the coming weeks and months. Projections for this upcoming season suggest a similar combined peak hospitalization burden compared with last year. Like last year, influenza is expected to be the major driver of peak combined respiratory hospitalization burden in the upcoming respiratory virus season.

With uptake of vaccination and monoclonal antibodies, peak RSV burden has been trending both downward and later in the season. COVID-19 activity is predicted to peak in early fall with less transmission during winter. Barring any substantial changes in vaccine uptake, transmissibility, or severity, influenza hospitalization burden is expected to be similar or less than last season.

Recommend​ations

Respiratory Virus Pre​vention

Talk to your patients abou​t respiratory virus infection prevention and control measures including immunizations, hand and respiratory hygiene, well-fitted masks, improving airflow or ventilation, and staying home when sick. Test and treat populations at risk of severe disease who are eligible for respiratory virus therapeutics.

Immuni​zations

Immunizations are a critical tool for prevention of influenza, RSV, and COVID-19 infections, especially for persons at higher risk for severe disease. Offer vaccines to all eligible persons at every opportunity including weekend and evening clinics, during sports physicals, or sick visits. For the most current information on respiratory virus immunizations, visit the CDPH Public Health for All Vaccines page.

Download the printable PDF.

[1] COVID-19 vaccine is available for persons 6 months and older.
[2] Two doses given at least 4 weeks apart are recommended for ages 6 months-8 years who are getting flu vaccine for the first time.
[3] Protect infants with either prenatal RSV vaccine or infant dose of nirsevimab or clesrovimab.
[4] RSV vaccination during pregnancy or for adults is currently recommended once rather than annually.

Immunizations are recommended for healthcare workers and other people who live with or care for people at higher risk of serious illness from respir​atory viruses. This is especially true for people who work in long-term care facilities which are home to many of the people most vulnerable to respiratory viruses. For talking points on immunizations in long-term care facilities, see CDPH's Flu, COVID-19, and RSV Talking Points for Long-Term Care Facilities.​

Testing

Test patients with suspected respiratory virus infections to detect and distinguish between different viral etiologies. This helps guide management for treatable viral infections or diseases of public health importance, especially for those at higher risk for severe infection, those with severe or progressive respiratory illness, and those with potential exposures to animals infected with novel or variant influenza.

When respiratory viruses are co-circulating, outpatient clinicians should test using multiplex panels (molecular assays that can detect multiple seasonal respiratory viruses) for influenza, RSV, and COVID-19. If patients test negative for influenza, RSV, and COVID-19, additional testing for other respiratory viruses with broader multiplex panels can be performed if clinically indicated.

In outpatients, rapid molecular tests are recommended over rapid antigen tests due to their higher sensitivities to detect respiratory viruses. However, rapid antigen tests for influenza and COVID-19 are available for over-the-counter purchase. Rapid antigen tests can be used if molecular testing is unavailable. A positive result from an at-home antigen test is likely to be a true positive. If negative, consider in-clinic testing if indicated. Always test with molecular assays for RSV, influenza, and SARS-CoV-2 in hospitalized patients.

Influenza testing by rRT-PCR is encouraged in situations where sequencing or subtyping may be needed, including:

• Severe cases including hospitalized, intensive care unit (ICU), and/or fatal cases

• Acute respiratory illness outbreaks of public health concern

• Persons with recent close contact or exposures within 10 days of symptom onset that are concerning for avian, variant, or novel influenza infection (e.g., variant influenza A (H3N2)v, (H1N2)v, or (H1N1)v, or avian influenza H5N1 or H7N9). If avian influenza is suspected, please see CDPH Avian Influenza A(H5N1) for testing, treatment and isolation guidance.
  

Specimens should be collected within 24-72 hours of symptom onset and no later than 5 days after (up to 10 days when avian, variant, or novel influenza is suspected). Specimens from ICU or hospitalized patients should be sent to a public health laboratory (PHL) as soon as possible, preferably within 24-48 hours of collection. Influenza rRT-PCR testing and subtyping are available at CDPH's Viral and Rickettsial Disease Laboratory (VRDL) and 24 PHLs. Providers should contact their local PHL for submission instructions. PHLs can contact CDPH-VRDL for additional assistance when needed.

Information to assist healthcare providers about when to consider respiratory virus testing is available at Clinical Guidance for Hospitalized and Non-Hospitalized Patients When SARS-CoV-2 and Influenza Viruses are Co-Circulating | Influenza (Flu) | CDC, Information for Clinicians on Influenza Virus Testing,Respiratory Syncytial Virus for Healthcare Professionals, and Overview of Testing for SARS-CoV-2.

Therapeutics

Rapid treatment with influenza and COVID-19 antivirals decreases the risk of serious illness, hospitalization, and death. Evaluate symptomatic patients and offer therapeutics as soon as possible to eligible patients, especially those at higher risk for severe disease or who may transmit to high-risk contacts.

Immediately prescribe either oseltamivir (Tamiflu®) or single-dose baloxavir (Xofluza®) for any patient with suspected or confirmed influenza who is at higher risk for influenza complications or who may transmit to high-risk contacts. Prescribe oseltamivir to any patient who is hospitalized or who has severe, complicated, or progressive illness. Nirmatrelvir-ritonavir (Paxlovid®) is the first-line therapy for mild to moderate COVID-19 in the outpatient setting.

Preventive antibodies are available for some people who are moderately or severely immunocompromised for additional protection against COVID-19, or for infants to protect against RSV. Antiviral medications can also be used to prevent influenza and COVID-19 before or after exposures.

Recently FDA approved Ensitrelvir (Xocova®) may be used aspost-exposure prophylaxis of COVID-19 within 72 hours of contact with an individual who has COVID-19. Providers should check compatibility with patient insurance plans as financial assistance programs are evolving for this new drug. For some insurance plans, a $0 co-pay card may be available. Contracts with Medi-Cal are pending. Ensitrelvir may not be accessible to all patients.

Visit the CDPH Healthcare Professionals Hub for more information about therapeutics.

Infection Prevention and Control Measures

During periods of increased transmission of respiratory viruses and in the event of a healthcare facility outbreak, healthcare facilities should implement source control policies as described in CDPH's Source Control Guidance for Healthcare Settings and in accordance with their local health department recommendations or requirements.

Healthcare personnel working in hospitals and long-term care facilities (including skilled nursing facilities) should empirically apply appropriate Transmission-Based Precautions when examining a patient with known or suspected respiratory infection. Precautions should be based on the clinical syndrome and the likely etiologic agents (e.g., which respiratory viruses are circulating in the community, contact with someone known to have a specific respiratory viral infection) and modified once the pathogen is identified or a transmissible infectious etiology is ruled out. If the etiology is uncertain and SARS-CoV-2 is considered possible, precautions should generally follow those recommended for SARS-CoV-2 until this diagnosis is excluded. See Appendix A in the CDC Guideline for Isolation Precautions for syndromic and pathogen-specific recommendations for Transmission-Based Precautions, including guidance on the recommended duration of isolation. See also CDC Guidance on Preventing Transmission of Viral Respiratory Pathogens in Healthcare Settings.

For more information on infection prevention and control of respiratory viruses in skilled nursing facilities, healthcare providers may visit the CDPH Recommendations for Prevention and Control of COVID-19, Influenza, and Other Respiratory Viral Infections in California Skilled Nursing Facilities (PDF).

Respiratory Virus Season Resources