FluMist® Influenza Vaccine Clinical Trials, Dosage, Indication, Side Effects

AstraZeneca's FluMist® (Fluenz® Tetra) Influenza Vaccine Live, Intranasal contains weakened live viruses that trigger an immune response in the nose, where people usually catch the flu, says the U.S. Centers for Disease Control and Prevention (CDC). FluMist nasal vaccine works in the nose, cells, and bloodstream to help provide flu protection within 14 days. FluMist then triggers people's immune systems to build defenses (called antibodies) for people 2-49 years of age. 

FluMist is the only U.S. Food and Drug Administration (FDA) --approved flu vaccine with a needle-free nasal spray administrative technique. Estimates show that as many as 2 in 3 children and 1 in 4 adults have intense fears around needles. FluMist was initially approved by the FDA in 2003. The FDA issued STN: BL 125020/2606 on July 9, 2020, and BL 125020/2852 on July 27, 2022, and was approved for the 2024–2025 Influenza Season. On October 24, 2023, AstraZeneca announced a Supplemental Biologics License Application (sBLA) for approving a self- or caregiver-administered option for FluMist has been accepted for review by the U.S. FDA. On August 6, 2024, the FDA issued STN: BL 125020/3070. On September 20, 2024, the FDA announced  (STN: 125020) approval of FluMist for self- or caregiver-administration. A prescription is still required to receive FluMist Home.

“Today’s approval of the first influenza vaccine for self- or caregiver administration provides a new option for receiving a safe and effective seasonal influenza vaccine potentially with greater convenience, flexibility, and accessibility for individuals and families,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, in a press release. The FDA granted this approval of FluMist to MedImmune LLC.

ATC code: J07BB03; CAS Number: 1704512-59-3.

Delaware-based AstraZeneca (AZN) is a global, science-led biopharmaceutical company focusing on discovering, developing, and commercializing prescription medicines. Click here to find a FluMist location in the USA.

FluMist Indication

FluMist is FDA-approved for preventing influenza disease caused by influenza virus subtypes A and B in individuals 2 through 49 years of age. It is the first vaccine to prevent influenza that does not need to be administered by a healthcare provider.

Flumist Dosage

There are now two approved options for receiving FluMist. The vaccine may be administered by a healthcare provider in a healthcare setting (including a pharmacy) or by the vaccine recipient or a caregiver who is 18 years or older. FluMist is sprayed into the nose. Vaccine recipients and caregivers who administer FluMist will be sent the vaccine, the Prescribing Information, Information for Patients and their Caregivers, and Instructions for Use.

FluMist Quadrivalent Side Effects

The most common side effects are runny or stuffy nose, sore throat, and fever over 100°F. FluMist Quadrivalent is contraindicated in persons who have had a severe allergic reaction (e.g., anaphylaxis) to any vaccine component, including egg protein, or after a previous dose of any influenza vaccine, and in children and adolescents receiving concomitant aspirin or aspirin-containing therapy. In clinical trials, the risks of hospitalization and wheezing were increased in children <24 months of age who received trivalent FluMist. In a study published by the AAP journal Pediatrics on March 25, 2022, LAIV4 was not associated with an increased frequency of asthma exacerbations, an increase in asthma-related symptoms, or a decrease in peak expiratory flow rate compared with IIV4 among children aged 5 to 17 years with asthma.

FluMist Vaccine Effectiveness

Since the 2018 flu season, the FLUMIST vaccine has demonstrated effectiveness like other FDA-approved flu shots.

FluMist Availability

In 2025, FluMist Home will utilize an online pharmacy where eligible individuals complete a questionnaire that a pharmacist reviews before receiving their vaccine for shipment. In 2024, FluMist will continue to be available in offices and pharmacies for healthcare professionals to administer. More information is available at www.FluMist.com.

Fluenz® Tetra Influenza Vaccine

The LAIV) has been used in the U.K. since 2013 to protect children against influenza infection. In the United Kingdom (U.K.), over 3 million students in secondary school years 7 to 11 will be offered the nasal spray vaccine through their school's vaccination program starting September 2023. On December 16, 2022, the U.K. Health Security Agency confirmed Fluenz Tetra offers protections for scarlet fever and group A strep infections in children.

FluMist News

September 20, 2024 - Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, commented, “Getting vaccinated each year is the best way to prevent influenza, which causes illness in a substantial proportion of the U.S. population every year and may result in serious complications, including hospitalization and death. This approval adds another option for vaccination against influenza disease and demonstrates the FDA’s commitment to advancing public health.”

October 24, 2023 - AstraZeneca confirmed Supplemental Biologics License Application for the approval of a self- or caregiver-administered option for FLUMIST® QUADRIVALENT.

September 5, 2023 - AstraZeneca announced FLUMIST® QUADRIVALENT (Influenza Vaccine Live, Intranasal) doses were available in the U.S. for the 2023-2024 flu season.

February 28, 2023 - Japan health ministry panel endorses nasal flu vaccine for children.

November 10, 2022 - AstraZeneca confirmed Flumist vaccine revenues reached about 59 million year-to-date.

September 23, 2022 - AstraZeneca announces FLUMIST® QUADRIVALENT doses are available in the U.S. for the 2022-2023 influenza season. "Educating communities about flu safety measures and encouraging yearly flu vaccination remains an important part of reducing serious and contagious health threats," said Liz Bodin, Vice President, U.S. Respiratory & Immunology, AstraZeneca.

March 25, 2022 - The results from a limited (151 children) clinical trial published by the AAP suggest within 42 days of vaccination, 10.8% of children who received the intranasal LAIV4 experienced an asthma exacerbation compared with 14.7% of those who received the intramuscular IIV4; risk difference -0.0390, 90% CI -0.1453 to 0.0674).

August 31, 2021 - AstraZeneca announced that FLUMIST® QUADRIVALENT vaccine doses are available in the U.S. for the 2021-2022 influenza season. FLUMIST QUADRIVALENT is the only U.S. FDA-Approved nasal-spray flu vaccine.

August 26, 2021 - The U.S. FDA confirmed that (3) FluMist Quadrivalent lots from MedImmune, LLC, were released. 

June 1, 2021 - Global Nasal Spray Vaccine Market 2020 Development Analysis – AstraZeneca FluMist, Cipla, BCHT

February 11, 2021 - AstraZeneca plc published financial results, which stated Flumist Total Revenue, entirely comprising Product Sales, increased by 161% in the year (153% at CER) to $295 m, reflecting the greater use of influenza vaccines as health authorities in northern-hemisphere countries expanded seasonal-vaccination programs beyond typical levels during the ongoing COVID-19 pandemic. In the U.S., sales increased by 254% in the year to $70m and, in Europe, by 135% (126% at CER) to $219m.

November 25, 2020 -  Israel ordered AstraZeneca's FluMist vaccines for its citizens.

August 13, 2020 - AstraZeneca Ships FLUMIST® QUADRIVALENT Vaccine in the U.S. for the 2020-2021 Flu Season. AstraZeneca has increased production of FluMist QUADRIVALENT doses in the U.S. by over 25% more than planned, most of which are expected to be available by the end of September.

FluMist Quadrivalent Clinical Trials

Astra Zeneca's FluMist has been studied in several clinical trials.