Issue 1775: September 12, 2024

Ask the Experts: Immunize.org Answers Questions about Vaccination against Respiratory Viruses for Fall and Winter 2024

As an additional service to IZ Express readers, we periodically publish special editions such as this one, providing you with new and updated Ask the Experts questions and answers from Immunize.org experts. This issue includes 13 Q&As based on the fall 2024 updates to CDC clinical guidance and ACIP recommendations for vaccination against influenza, COVID-19, and RSV.
 
You can find all of these questions and answers, plus more than 1,300 others about vaccines and vaccine administration, on our "Ask the Experts" main page at www.immunize.org/ask-experts.
 
Immunize.org's team of experts includes Kelly L. Moore, MD, MPH (team lead); Carolyn B. Bridges, MD, FACP; Iyabode Beysolow, MD, MPH; and Jane R. Zucker, MD, MPH.
 
Influenza
COVID-19 
RSV 

Influenza

Q: Please summarize what’s new in CDC’s 2024–25 season influenza vaccine recommendations.

A: Yearly influenza vaccination continues to be recommended for everyone age 6 months and older. Changes relevant to clinical practice in the CDC’s published ACIP recommendations for influenza vaccination in the 2024–25 season are summarized below.

  • ACIP now recommends high-dose inactivated influenza vaccine (HD-IIV) or adjuvanted inactivated (aIIV) influenza vaccine (each licensed by FDA for people age 65 years or older) as acceptable options for influenza vaccination of solid organ transplant recipients age 18 through 64 years who are on immunosuppressive medication regimens. There is no preference for aIIV or HD-IIV over any other age-appropriate inactivated or recombinant influenza vaccine in this group.
  • The HD-IIV vaccine, which is now trivalent, is given at a dose of 0.5 mL (the previous dose for quadrivalent HD-IIV was 0.7 mL).
  • ACIP affirmed that everyone age 6 months and older who has an egg allergy should receive influenza vaccine. Any influenza vaccine (egg based or non-egg based) that is otherwise appropriate for the recipient’s age and health status may be used. ACIP updated its recommendation to state that egg allergy alone necessitates no additional safety measures for influenza vaccination beyond those recommended for any recipient of any vaccine, regardless of severity of previous reaction to egg. All vaccines should be administered in settings in which personnel and equipment needed for rapid recognition and treatment of acute hypersensitivity reactions are available.

The current ACIP recommendations for influenza vaccination are available here.


Q: A 1-year-old was inadvertently given a 0.25 mL dose of FluLaval rather than the recommended 0.5 mL dose. What should we do?

A: If the error is discovered on the same clinic day you can administer the other “half” of the FluLaval dose on the same day. If the error cannot be corrected on the same day, the partial dose should not be counted. The child should be recalled to the office as soon as possible and given a full age-appropriate repeat dose, either a 0.5 mL dose of FluLaval, a 0.5 mL dose of Fluarix, a 0.25 mL or 0.5 mL dose of Fluzone, a 0.25 mL dose of Afluria, or a 0.5 mL dose of Flucelvax.


Q: Are any of the available influenza vaccines recommended over others?

A: For people age 6 months through 64 years, CDC recommends any available age-appropriate influenza vaccine product.
 
For adults age 65 years and older, three influenza vaccines are preferentially recommended: Fluzone High-Dose (HD-IIV, Sanofi), Flublok recombinant (RIV, Sanofi), and Fluad adjuvanted (aIIV, CSL Seqirus). In June 2022, ACIP concluded that these three vaccines are potentially more effective than standard dose, unadjuvanted flu vaccines. However, if none of the three products are available, people age 65 years and older should get any other age-appropriate influenza vaccine.
 
Review the full explanation for the ACIP decision to prefer these products in this age group in the 2022 ACIP recommendations for influenza vaccination: www.cdc.gov/mmwr/volumes/71/rr/pdfs/rr7101a1-H.pdf.
 
ACIP recommends that solid organ transplant recipients (SOTRs) age 18 years through 64 years have the option of receiving HD-IIV or aIIV, both of which are licensed for people age 65 years or older. However, HD-IIV and aIIV are not preferentially recommended over age-appropriate influenza vaccine products for SOTRs.


COVID-19 

Q: How long should people wait after their most recent dose of 2023–2024 Formula COVID-19 vaccine before getting a 2024–2025 Formula COVID-19 vaccine?

A: In general, CDC recommends waiting a minimum of 8 weeks (2 months) since the last 2023–2024 Formula COVID-19 vaccine to receive an age-appropriate 2024–2025 Formula COVID-19 vaccine.
 
Previously unvaccinated children age 6 months through 4 years are recommended to receive a 2-dose (Moderna) or 3-dose (Pfizer-BioNTech) primary series of COVID-19 vaccine. Previously unvaccinated moderately or severely immunocompromised people are recommended to receive a 3-dose primary series of mRNA COVID-19 vaccine (either product) or a 2-dose primary series of Novavax COVID-19 vaccine. Any previously unvaccinated person who receives Novavax COVID-19 vaccine should receive a 2-dose primary series, 3–8 weeks apart. If a person in one of these categories initiated their primary series with a 2023–2024 formula vaccine, they are recommended to follow the age-appropriate recommended schedule for completion of the primary series with the 2024–2025 formula of the same brand.


Q: Should adults age 65 years and older routinely receive a dose of COVID-19 vaccine every 6 months?

A: ACIP has not made a routine recommendation for COVID-19 vaccination of older adults every 6 months. Although vaccine effectiveness against hospitalization in this age group wanes significantly by 6 months after vaccination, the ACIP recommendation made in February 2024 for adults in this age group to receive an additional dose of the 2023–2024 Formula COVID-19 vaccine was based upon conditions at the time and the expectation that COVID-19 would continue to circulate through the summer of 2024. ACIP will evaluate data and make a decision concerning an additional dose during the 2024–25 respiratory virus season as the season progresses.


Q: My patient had the first dose of the 3-dose primary series of Pfizer-BioNTech COVID-19 vaccine at age 4 years and turned 5 before dose two. What should she get now?

A: CDC states that a person who moves to an older age group between vaccine doses should receive the vaccine product and dosage for the older age group for all subsequent doses.
 
Children who transition from age 4 years to age 5 years during the initial vaccination series should receive 1 dose of the 2024–2025 vaccine from the same manufacturer at the dosage authorized for children age 5–11 years on or after turning age 5 years.


RSV 

Q: How often should the RSV vaccine be given?

A: All three RSV vaccines are currently licensed and recommended as a one-time dose for any person. Data are not available at this time to make recommendations for revaccination. At this time, a pregnant person who receives Abrysvo (Pfizer) during one pregnancy is not recommended to receive Abrysvo during a subsequent pregnancy: in subsequent pregnancies, the baby should receive nirsevimab (Beyfortus, Sanofi) after delivery for RSV protection. ACIP will make decisions concerning RSV revaccination as more data become available over time. 


Q: Why did ACIP change its RSV vaccination recommendations for older adults in 2024 to remove the option for vaccination of healthy people 60 through 74 who would like to be vaccinated?

A: In 2023, when RSV vaccines were initially licensed, ACIP recommended use of RSV vaccine for anyone 60 years and older based on shared clinical decision-making, which includes a conversation about individual risks and benefits of vaccination with a healthcare provider. The recommendation was made when there were limited data about how well the vaccine would work in preventing RSV-associated hospitalization or death due to the relatively healthy older adults enrolled in the clinical trials. There was also a question about whether (or how frequently) a person would need revaccination and whether the vaccination might increase the rare risk of Guillain-Barré syndrome. Given these uncertainties, ACIP members felt that people should have the option to choose to receive RSV vaccine or wait until their risk of serious RSV disease escalates, as it does after age 75. Shared clinical decision-making proved time-consuming and difficult to implement for healthcare providers and patients, due to the lack of clarity about who should prioritize RSV vaccination.
 
Updated evidence on the balance of RSV vaccination benefits and risks led ACIP in June 2024 to make a definitive routine age-based recommendation for adults age 75 years and older, accompanied by a risk-based recommendation for those age 60 through 74 years with specific high-risk conditions. Due to the relatively small benefit of vaccination for healthy people younger than age 75 and the ongoing uncertainty about revaccination, the option for vaccination of people age 60 through 74 years without risk factors for severe RSV disease was removed.


Q: What are the high-risk conditions specified by ACIP as indications for RSV vaccination among adults age 60 through 74 years?

A: Because of the strong association between the risk of severe RSV disease and age, ACIP recommends RSV vaccination of all adults age 75 years or older. ACIP has specified several conditions as reasons for RSV vaccination before age 75 years (age 60 through 74 years) due to their association with a high risk of hospitalization with severe RSV disease compared to otherwise healthy adults of the same age. These conditions are similar to, but not the same as, high-risk conditions specified for pneumococcal or influenza vaccination. An individual’s risk is increased further if they have more than one of the conditions.

  • Non-immunocompromising chronic health conditions:
    • Chronic cardiovascular disease (such as heart failure, coronary artery disease, or congenital heart disease [excluding isolated hypertension])
    • Chronic lung disease (such as chronic obstructive lung disease [COPD], emphysema, asthma, interstitial lung disease, or cystic fibrosis)
    • End-stage kidney disease or dependence on hemodialysis or other renal replacement therapy
    • Diabetes mellitus complicated by chronic kidney disease, neuropathy, retinopathy, or other end-organ damage, or requiring treatment with insulin or sodium-glucose cotransporter-2 (SGLT2) inhibitor
    • Severe obesity (measured as a body mass index of 40 kilograms per meter squared or greater)
    • Chronic liver disease (such as cirrhosis)
    • Neurologic or neuromuscular conditions causing impaired airway clearance or respiratory muscle weakness (such as poststroke dysphagia [swallowing dysfunction], amyotrophic lateral sclerosis [ALS], or muscular dystrophy [excluding history of stroke without impaired airway clearance])
    • Chronic blood disorders (such as sickle cell disease, thalassemia)
  • Moderate or severe immune compromise (due to a medical condition or due to immunosuppressive medications or treatment)
  • Overall frailty (based on an assessment of frailty)
  • Residence in a nursing home or other long-term care facility
  • Other chronic medical conditions or risk factors not specified in this list that a healthcare provider determines might increase the risk of severe disease due to RSV respiratory infection

People age 60 through 74 years who do not have a medical condition or risk factor that increases their risk of severe RSV disease are not recommended to receive RSV vaccine: they should wait to be vaccinated until a high-risk condition develops or until they turn 75, whichever comes first.


Q: I have a 69-year-old patient who requested RSV vaccination. He has controlled hypertension and no other underlying medical conditions. Is RSV vaccination indicated?

A: No. RSV vaccination is not recommended for people his age with hypertension and no other risk conditions. People age 60 through 74 years who do not have a medical condition or risk factor that increases their risk of severe RSV disease are not recommended to receive RSV vaccination at this time.


Q: What is the recommendation for use of RSV vaccine during pregnancy?

A: Pregnant people between 32 and 36 weeks and 6 days’ gestation during the months of September through January in the United States should get one dose of the Pfizer RSVpreF vaccine (Abrysvo) to protect their babies during their first RSV season after birth. Only Abrysvo is FDA-approved and recommended for pregnant people. Arexvy (by GSK) and mResvia (Moderna) are not approved and should not be given during pregnancy.
 
In most of the continental United States, maternal RSV vaccine is recommended only September through January. Those who provide health care to pregnant people who live in areas with different patterns of RSV seasonality, such as Alaska, Hawaii, parts of Florida, or other jurisdictions outside the continental United States, should follow guidance from state or territorial public health authorities about the timing of RSV vaccination during pregnancy in their regions.
 
RSV vaccine is only recommended as a single dose; revaccination is not recommended. However, RSV vaccination during one pregnancy is not expected to protect infants resulting from future pregnancies. Therefore, a person who is currently pregnant and received RSV vaccine before the current pregnancy should be counseled that their infant should receive nirsevimab (Beyfortus, Sanofi) for prevention of RSV disease after birth.


Q: Can I give RSV vaccine to someone who is at 36 weeks and 5 days’ gestation?

A: Yes. Pfizer’s RSV vaccine (Abrysvo) may be administered to a previously unvaccinated pregnant person from 32 weeks through 36 weeks and 6 days’ gestation. RSV vaccine should not be administered to someone at 37 weeks’ gestation or beyond.
 
RSV vaccine should be administered at least 2 weeks before delivery to allow time for the maternal immune system to create antibodies and transfer sufficient antibodies to the fetus for adequate protection after birth. If the gestational age is appropriate, but clinical judgment is that delivery is likely to occur within 2 weeks, it is reasonable to defer vaccination and plan to administer nirsevimab RSV preventive antibody (Beyfortus, Sanofi) to the infant after delivery. Infants born less than 14 days after maternal RSV vaccination are recommended to receive nirsevimab after birth to ensure adequate protection.


Q: An error was made resulting in an infant receiving RSV vaccine instead of the nirsevimab RSV preventive antibody. What should be done?

A: The safety and effectiveness of RSV vaccines have not been studied in infants. The family should be informed of the error, and nirsevimab (Beyfortus, Sanofi) should be administered as recommended as soon as feasible. CDC experts recommend that if you administer nirsevimab within 72 hours of the error, and you know where the RSV vaccine was injected, you should administer the nirsevimab in a different anatomic site. Facilities that stock RSV vaccine and nirsevimab should put systems and procedures in place to prevent this type of error, including staff training, clear labeling, and warnings in storage units. This medication error and any suspected adverse events following the error should be reported to the Vaccine Adverse Event Reporting System (VAERS) at https://vaers.hhs.gov.

For additional information about this type of error, see CDC’s COCA Now: Clinician Outreach Communication Activity update, dated January 22, 2024, at https://emergency.cdc.gov/newsletters/coca/2024/012224.html.


Suggest a question for "Ask the Experts"

If you have a question that you think may be of interest to our readers, please send it to us using our online form. We will consider it for inclusion in a future update of the “Ask the Experts” feature.

About IZ Express

IZ Express is supported in part by Grant No. 1NH23IP922654 from CDC’s National Center for Immunization and Respiratory Diseases. Its contents are solely the responsibility of Immunize.org and do not necessarily represent the official views of CDC.

IZ Express Disclaimer
ISSN 2771-8085

Editorial Information

  • Editor-in-Chief
    Kelly L. Moore, MD, MPH
  • Managing Editor
    John D. Grabenstein, RPh, PhD
  • Associate Editor
    Sharon G. Humiston, MD, MPH
  • Writer/Publication Coordinator
    Taryn Chapman, MS
    Courtnay Londo, MA
  • Style and Copy Editor
    Marian Deegan, JD
  • Web Edition Managers
    Arkady Shakhnovich
    Jermaine Royes
  • Contributing Writer
    Laurel H. Wood, MPA
  • Technical Reviewer
    Kayla Ohlde

This page was updated on .