Influenza

FluMist by AstraZeneca (Live Quadrivalent Influenza)

Captured 2022-12-09

Document Highlights

Initial U.S. Approval: 2003

FluMist Quadrivalent is a vaccine indicated for active immunization for the prevention of influenza disease caused by influenza A subtype viruses and type B viruses… approved for use in persons 2 through 49 years…

CONTRAINDICATIONS
Severe allergic reaction (e.g., anaphylaxis) to any component of FluMist Quadrivalent, including egg protein…

Increases in wheezing and hospitalization (for any cause) were observed in children… who received FluMist compared to those who received inactivated Influenza Virus Vaccine… [From Table 1: 4.2% of children aged 6-23 months were hospitalized and 5.9% experienced wheezing.] Most hospitalizations observed were due to gastrointestinal and respiratory tract infections…

[U]nsolicited adverse reactions in children… were abdominal pain [2%]… and otitis media [3%]…

Abdominal pain was reported in 12% of FluMist recipients…

Postmarketing Experience
– Pericarditis
– Exacerbation of symptoms of mitochondrial encephalomyopathy (Leigh syndrome)
– Nausea, vomiting, diarrhea
– Hypersensitivity reactions (including anaphylactic reaction, facial edema, and urticaria)
– Guillain-Barré syndrome, Bell’s Palsy, meningitis, eosinophilic meningitis, vaccine-associated encephalitis
– Epistaxis
– Rash

Each 0.2 mL dose contains… [four strains of] live attenuated influenza virus…

Each 0.2 mL dose also contains… monosodium glutamate [MSG]… porcine gelatin…

Each dose contains residual amounts of ovalbumin…

Shedding with FluMist… [89% of children 6-23 months of age were shedding detectable amounts of flu viruses during the 28 days following vaccination. 7% were still shedding after day 11.]

A prospective, randomized, double-blind, placebo-controlled trial was performed in a daycare setting in children younger than 3 years of age to assess the transmission of vaccine viruses from a vaccinated individual to a non-vaccinated individual.

[T]he probability of acquiring a transmitted vaccine virus was estimated to be 2.4%…

FluMist Quadrivalent has not been evaluated for its carcinogenic or mutagenic potential or its potential to impair fertility.

Comments

The Flumist Quadrivalent insert claims that a previous version of the Flumist vaccine was tested in two studies against a saline placebo.

These studies were conducted prior to the Flumist vaccine not being recommended by the CDC in the 2016-2017 and 2017-2018 seasons due to it being only 3% effective.

In the insert, only information on unsolicited adverse reactions were provided for one of these studies, and no time frame was included:

"In a separate saline placebo-controlled trial (D153-P526) in a subset of older children and adolescents 9 through 17 years of age who received one dose of FluMist, the solicited adverse reactions as well as unsolicited adverse reactions reported were generally consistent with observations from the trials in Table 2. Abdominal pain was reported in 12% of FluMist recipients compared to 4% of placebo recipients and decreased activity was reported in 6% of FluMist recipients compared to 0% of placebo recipients."

For the other study utilizing a saline placebo, data from a study which used an "Allantoic Fluid containing Sucrose-Phosphate-Glutamate (AF-SPG) placebo" was grouped together with results from the saline placebo trial, in Table 2, obscuring the data (page 7).

Why placebo controlled trials are important.

Vaccine.Guide

FluMist by AstraZeneca (Live Quadrivalent Influenza)