As AZ works to assess FluMist efficacy woes, CDC worries flu vaccination rates could slip

By Eric Sagonowsky Oct 4, 2016 10:27am

About 20 million people and one-third of children in the U.S. received AstraZeneca’s FluMist last year to protect against the seasonal virus, health officials told reporters during a press conference. And with the nasal mist no longer an option this year, the CDC is concerned that vaccination rates could suffer.

AstraZeneca said it’s working to assess a dropoff in effectiveness for its nasal flu shot, but in the meantime, the CDC is hoping it can get vaccination rates higher than last year’s 45.6%. According to Director Thomas Frieden, a 5% increase would reduce flu illnesses by 800,000 and hospitalizations by 10,000.

Frieden and other health officials said there’s “no excuse” to skip vaccination in light of the FluMist developments, saying that other vaccine manufacturers boosted their production to compensate. Between 157 million and 168 million doses will be available this year; 93 million have already been shipped.

In June, the CDC’s Advisory Committee on Immunization Practices pulled its FluMist recommendation after weighing "data showing poor or relatively lower effectiveness" for three previous flu seasons. For last year’s flu season, FluMist was just 3% effective in children aged 2 to 17, according to data the body received in May.

“It’s a surprising finding and we really do hope we can get an effective nasal spray back on the market and recommended as soon as possible,” Frieden said. The nasal vaccine is “certainly preferable to getting a shot” for some children, he said.

In an interview with The Washington Post, Frieden said the agency is “concerned” vaccination rates could suffer without the nasal option. Approximately 145 million people received a flu vaccination of some type last year.

While FluMist won’t be available in the U.S. this season, AZ “continues to pursue a broad-based scientific investigation into the causes of the reduced effectiveness,” a spokesperson told FiercePharma.

“We have seen, through both our data and investigation in the labs, that the H1N1 strain is not replicating as well as it should. Our goal is to select a better performing A/H1N1pdm09 LAIV strain for inclusion in future seasons, including the upcoming 17-18 season,” the spokesperson said.

FDA personnel and outside experts are working on the investigation as well.

AstraZeneca’s FluMist Quadrivalent brought in $206 million in the U.S. last year out of a total worldwide haul of $290 million. The company’s U.S. setback comes at a time of stepped-up competition in the flu vaccine space, with the formation of Seqirus adding yet another player vying for market share. Formed last year from the joining of bioCSL and Novartis’ flu vaccines lineup, Seqirus won FDA approval in May for its Flucelvax Quadrivalent. It’s now the second-largest flu vaccine provider behind Sanofi.

Influenza nasal spray AstraZeneca bioCSL Centers for Disease Control and Prevention Flucelvax Flumist Pharma