LAC DPH Health Update: Fall Influenza and COVID-19 Vaccination


Key Messages

  • LA County influenza surveillance shows much higher activity compared to this time of year pre-pandemic. In previous years, an early start to the season was associated with a season with substantially higher influenza activity.
  • Annual influenza vaccination is recommended for people ages 6 months and older, with higher dose or adjuvanted vaccine preferred for adults ≥65 years.
  • One bivalent mRNA COVID-19 booster dose is recommended for people ages 5 years of age and older at least 2 months after their last monovalent booster or primary series COVID-19 vaccine dose. A Novavax monovalent COVID-19 vaccine may now be used in limited situations as a first booster (instead of a bivalent mRNA booster dose) in people ages 18 and older.
  • Giving multiple vaccines at the same visit increases the chance that a person will be up to date with their vaccinations. Coadministration of influenza and COVID-19 vaccines is strongly recommended to help ensure that people, especially older adults and others at increased risk of complications from both viruses, are better protected.
  • Older adults are at high risk of serious illness from both flu and COVID-19 and experience greater disease severity with flu/COVID-19 coinfection. In LA County to date, only 13% of eligible people ages ≥65 have received their recommended bivalent COVID-19 booster dose. Healthcare providers should urge patients aged 65 years and older at every healthcare encounter to get both their influenza vaccine and their updated fall COVID-19 booster as soon as possible. 




LA County surveillance data show that the percentage of respiratory specimens testing positive for influenza is higher so far this year compared to previous years (see figure). In 2017-18 and 2019-20, an early start to the season was a harbinger of seasons with substantially higher indicators of influenza activity and severity. To sign up for LA County Influenza and COVID Watch weekly surveillance reports, please email

Percentage of Respiratory Specimens Testing Positive for Influenza at LAC Sentinel Surveillance Laboratories by Season, 2016-17 Through 2022-23

Percentage of Respiratory Specimens Testing Positive for Influenza

*The 2020-2021 season contains a week 53. Data from the 2020-21 season have been shifted so that week 1 aligns across all seasons.

Influenza is associated with serious illnesses, hospitalizations, and deaths, particularly among older adults, very young children, pregnant persons, and persons of all ages with certain chronic medical conditions. Influenza also is an important cause of missed work and school. 

  • Annual influenza vaccination is recommended for everyone ages 6 months and olderwho do not have contraindications.
    • The Advisory Committee on Immunization Practices (ACIP) recommends that adults aged ≥65 years preferentially receive any one of the following higher dose or adjuvanted influenza vaccines: quadrivalent high-dose inactivated influenza vaccine (HD-IIV4), quadrivalent recombinant influenza vaccine (RIV4), or quadrivalent adjuvanted inactivated influenza vaccine (aIIV4).

The LA County COVID-19 community transmission level is currently substantial. Based on data from Europe, experience from previous years, and concerns about the emergence of more contagious variants, providers should be prepared for a late fall/winter COVID-19 surge. 

As the SARS-CoV-2 virus evolves, levels of neutralizing antibodies from previous infection and vaccination have declined. The bivalent Moderna and Pfizer COVID-19 boosters are expected to provide increased protection against both BA.4/BA.5 (the currently circulating variants) and the original SARS-CoV-2 strain, as well as to broaden the antibody response toward other variants.

In spite of being at much higher risk of COVID-19-associated hospitalization only 13% of eligible Los Angeles County residents aged 65 years and older have received their bivalent booster to date.

CDC recommends that everyone ages 6 months and older stay up to date with COVID-19 vaccination, including boosters.

  • COVID-19 vaccination is recommended for everyone ages 6 months and older.
  • A single bivalent mRNA booster dose is recommended for everyone ages 5 years and older if it has been at least 2 months since their last monovalent COVID-19 vaccine dose (i.e., final COVID-19 primary series dose or the last booster dose). This booster recommendation replaces all prior booster recommendations for these ages. The bivalent booster may be from a different manufacturer than the primary series or previous booster(s). Children who are 5 years of age can only get the Pfizer booster. People ages 6 years and older can get either a Pfizer or Moderna booster. Individuals cannot receive a bivalent booster dose without first completing a primary series. Monovalent mRNA vaccines are no longer authorized as a booster dose.
  • A single monovalent Novavax booster dose (instead of a bivalent mRNA booster) may be used in limited situations. People ages 18 years of age and older who have completed any primary series vaccination and who have not received any previous COVID-19 booster dose(s) and who are unable or unwilling to receive an mRNA vaccine may receive a Novavax booster dose. The monovalent Novavax booster dose can be given at least 6 months after completion of a primary series.
  • The CDC COVID-19 vaccine resources have been updated:


Actions Requested of Providers

  • Don’t miss an opportunity to strongly recommend the bivalent COVID-19 booster and flu vaccine – many patients are not aware of bivalent boosters or realize that they are eligible.
  • Offer and/or encourage influenza and COVID-19 vaccine administration at the same visit. This includes adjuvanted or high-dose influenza vaccines for patients ≥65 (see above); administer in separate limbs, if possible.
    Coadministration of the flu and COVID-19 vaccines will help ensure that people, especially older adults and others at increased risk of complications from both viruses, are better protected. This practice is recommended by the CDC and supported by the ACIP. COVID-19 vaccines administered with seasonal flu vaccine showed similar immunogenicity and similar or slightly higher reactogenicity; no safety concerns were identified. 
  • Contact your patients to schedule or refer them for COVID-19 and influenza vaccination. Please prioritize patients who are 65 years of age and older and patients with comorbidities or conditions (including pregnancy) that are associated with worse outcomes from COVID-19 and influenza.
    • Influenza and bivalent COVID-19 vaccines are widely available at pharmacies, Public Health vaccination sites, and community pop-up sites hosted by DPH Mobile Vaccine Partners, in addition to doctors’ offices and community clinics. 
    • Free in-home vaccination is available for people of all ages who have difficulty leaving home. Patients can be referred or can submit an online request (available in multiple languages) or call 211 or the Public Health Vaccine Call Center. More information is at the provider in-home vaccination webpage
    • Free rides to vaccination sites are available. Patients can call the Public Health Vaccine Call Center or visit the How To Get Vaccinated page to request this and/or find paratransit information.


Additional Resources

Influenza vaccination  

  • Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2022–23 Influenza Season MMWR
  • 2022-2023 Influenza Vaccination Recommendations and Guidance on Coadministration with COVID-19 Vaccines CDC webinar and slides
  • Influenza Information for Health Professionals CDC website

COVID-19 vaccination 



This communication was sent by Nava Yeganeh, MD, Medical Director, Vaccine Preventable Disease Control Program, Los Angeles County Department of Public Health

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