Preparing for the 2026–2027 Respiratory Virus Season: Vaccination, Masking, and Infection Control Recommendations (9/24/2026)

Intended Audience

Primary care clinicians; emergency department and urgent care providers; infection prevention personnel; hospital, skilled nursing, and long-term care facility administrators; laboratories; school health staff; and other congregate care settings in Marin County.

Purpose

Recipients should understand current COVID-19, influenza, and RSV activity heading into the 2026–2027 respiratory virus season; offer patients the updated 2026–27 immunizations recommended by the California Department of Public Health (CDPH) and the West Coast Health Alliance; and reinstate seasonal masking precautions in healthcare and long-term care facilities beginning November 1, 2026.

Summary

COVID-19 activity is rising nationally and in California. Influenza and RSV remain low but are expected to follow typical seasonal timing. Marin County Public Health (MCPH) has adopted the September 2026 California Department of Public Health (CDPH) / West Coast Health Alliance recommendations, which make COVID-19 vaccination available to anyone who wants to reduce their risk of severe illness. Clinicians and facilities should offer vaccination proactively, reinstate risk-based masking protocols, and prepare for the combined winter surge of COVID-19, influenza, and RSV.

Key Information

1. Situation: As of early September 2026, COVID-19 infections are growing or likely growing in nearly every state; wastewater levels are high or very high in dozens of states, with the West region highest. Influenza and RSV remain low but are expected to rise starting in October.
2. Elevated risk: Unvaccinated individuals; adults 65+; infants and young children; pregnant/postpartum people; immunocompromised individuals; residents and staff of long-term care and congregate settings.
3. Local context: Bay Area/Marin wastewater COVID-19 levels have been climbing since summer, consistent with state and national trends. RSV is expected to rise in October–November and influenza to peak in late January, as in prior seasons.
4. Risk to Marin County: MODERATE — rising COVID-19 transmission with comparatively low hospitalizations; the anticipated winter overlap of all three viruses could strain local healthcare capacity as in prior seasons.

Situation Overview

COVID-19 activity has been increasing since late summer 2026, driven primarily by the XFG variant. National CDC wastewater surveillance indicates high or very high SARSCoV-2 activity across much of the United States, particularly in the West. Local wastewater surveillance in Marin County shows a similar upward trend, consistent with increasing community transmission. Although hospitalizations and other severity indicators remain comparatively low relative to the increase in infections, respiratory virus activity is expected to continue rising through the fall. Influenza and RSV have not yet begun their typical seasonal increase. Still, they are expected to follow historical patterns, with RSV increasing in October–November and influenza accelerating in December before peaking in late January.

On August 27–28, 2026, the FDA approved updated, XFG-targeted 2026–27 formulations of four COVID-19 vaccines (Pfizer-BioNTech; ages 65+, or 5–64 years with a qualifying condition); Spikevax (Moderna; 65+, or 6 months–64 years with a qualifying
condition); mNEXSPIKE (Moderna; 65+, or 12–64 years with a qualifying condition); and Nuvaxovid (Novavax-Sanofi; 65+, or 12–64 years with a qualifying condition). Separately, on August 5, the FDA approved Moderna's mFLUSIVA (mRNA-1010) — the first mRNA-based influenza vaccine — for adults 50 and older (full approval 50–64; accelerated approval 65+, pending a confirmatory postmarketing study).

This FDA licensure is narrower than the CDPH/West Coast Health Alliance recommendations below. CDPH and the Alliance (CA, OR, WA, HI) — authorized under AB 144 to issue their own evidence-based recommendations informed by AAP, ACOG, and AAFP — issued consensus 2026–27 recommendations on September 4 that extend eligibility to anyone choosing vaccination to reduce their risk. Under AB 144, CDPH-recommended vaccines remain covered with no cost-sharing by California regulated plans regardless of the narrower FDA label. Marin County Public Health follows CDPH/West Coast Health Alliance guidance.

Relevance to Marin County

Bay Area wastewater monitoring shows COVID-19 concentrations climbing through summer into early fall 2026, raising the likelihood of overlapping winter virus circulation similar to 2025–26, when combined COVID-19/influenza/RSV hospitalizations peaked the week ending January 3. Older adults, infants, pregnant people, immunocompromised individuals, and long-term care residents/staff are at greatest risk and are the focus of this advisory.

Potential health impacts include complications in higher-risk populations, including pneumonia, exacerbation of chronic cardiopulmonary disease, and hospitalization of infants, older adults, and immunocompromised patients; and health-system impacts (i.e., healthcare workforce illness/staffing shortages and outbreaks in long-term care and congregate settings).

Recommendations

For All Clinicians / Recipients

1. Ask & consider: Ask about COVID-19, influenza, and RSV vaccination status at every visit; consider all three — alone or as co-infections — in the differential for respiratory illness.
2. Document & review: Document vaccination status in the medical record (submit to CAIR2 when applicable), and review facility surge plans, PPE/mask supplies, and sick-leave policies before winter volumes increase. 

Vaccination (per CDPH / West Coast Health Alliance 2026–27 Recommendations)

3. Offer COVID-19 vaccination to anyone 6 months and older who desires protection from COVID-19, and especially recommends vaccination for:
   • Infants and children 6–23 months (all)
   • Children 2–18 years with risk factors, or who have never been vaccinated against COVID-19
   • Adults 18–64 years with risk factors
   • All adults 65 and older
   • All people who are planning pregnancy, pregnant, postpartum, or lactating
   • Anyone in close contact with someone at higher risk
4. Offer influenza vaccination to all patients 6 months and older (including pregnant/postpartum), ideally by the end of October; two doses ≥4 weeks apart for first-time vaccinees ages 6 months–8 years. mFLUSIVA (mRNA-1010), FDA approved August 5, is now an option for adults 50+.
5. Offer RSV immunization: nirsevimab/clesrovimab or a prenatal RSV vaccine (32-36 weeks gestation) for infants under 8 months; select 8-19-month infants with risk factors entering a second season; and a one-time RSV vaccine for adults 75+ or 50-74 with risk factors.
6. Prioritize healthcare workers: CDPH/WCHA added healthcare workers as a specific recommended group this season for COVID-19, influenza, and RSV immunization, given exposure risk and workforce continuity.

Isolation and Infection Control

7. Masking in healthcare and long-term care facilities: Marin County Public Health will not issue a healthcare masking order at the start of the 2026–2027 respiratory virus season. However, from November 1, 2026 through March 31, 2027, MCPH strongly recommends that healthcare and long-term care facilities require staff and visitors to wear high-quality, well-fitting masks when in close contact with patients or residents, regardless of vaccination status. MCPH will continue to monitor respiratory virus activity and healthcare impacts and may consider additional infection prevention measures, including a masking requirement, if local conditions indicate a significant increase in transmission or healthcare burden.
8. Symptom-based isolation & access: Advise patients and staff with respiratory infections to stay home while symptomatic and resume activities after ≥24 hours of improvement and fever-free (without fever-reducing medication); actively facilitate vaccination access for staff, patients, and residents.

Reporting

Reporting timeframes vary by condition under Title 17 CCR §2500. Individual, uncomplicated COVID-19/influenza/RSV cases are not routinely reportable, but outbreaks in long-term care or congregate settings, and unusual clusters or severe presentations, are.

9. Report immediately: Suspected outbreaks in long-term care facilities, congregate settings, or healthcare facilities, and any unusual clusters or severe presentations, to Marin County Public Health.
10. Pediatric RSV deaths: Beginning January 1, 2027, all RSV deaths in children under 18 years will be nationally notifiable and included in upcoming Title 17 changes. A new reporting process for these pediatric RSV deaths will be in place for 2027, separate from current adult RSV death reporting.

Report to Public Health

Outbreaks of respiratory illness in long-term care facilities or other congregate settings, and unusual clusters or severe presentations of COVID-19, influenza, or RSV — report immediately by phone or email: 

• Email Long Term Care Facilities
• Email HHS Schools
• Call Marin County Public Health: (415) 473-4163 | After hours: (415) 499-7238

Resources

• Marin County Public Health — Respiratory Surveillance Dashboard
• Marin County Public Health — Wastewater Surveillance
• CDPH-2026–27 Respiratory Virus Season Immunization Recommendations
• Marin HHS -Public Health Notices and Respiratory Virus Season Information

Distribution: This message was distributed to Marin County clinicians, emergency departments, urgent care providers, infection prevention personnel, laboratories, schools, and long-term care facilities.

Note: This advisory was drafted with AI assistance and reviewed by MCPH staff before distribution.