This year UPMC says the egg doesn’t come first in flu vaccines

Pittsburgh Post-Gazette

UPMC is planning to go almost entirely egg-free this year — with flu vaccines, that is. As the season nears, it’s stocking up on two flu vaccines that are not made using chicken eggs.

They’ll be the main vaccines offered at UPMC facilities, including primary care providers and urgent care clinics.

The egg-free Flublok is approved by the U.S. Food and Drug Administration for people 18 years old and up; Flucelvax is approved for anyone older than 4. UPMC will offer the egg-based FluZone to patients age 6 months to 4 years because the egg-free versions haven’t yet been approved by the FDA for people that young. Why the shift away from eggs? “It appears that the egg-free products were about 10 percent better,” said UPMC’s Richard Zimmerman, chief of the Pittsburgh site of the multicenter U.S. Influenza Vaccine Effectiveness Network of the Centers for Disease Control and Prevention. Flucelvax has a small amount of egg, he said.

Dr. Zimmerman explained that existing vaccine technology is at least 50 years old. Vaccine viruses have been grown in eggs, and that takes time, he said. Because the viruses change, or mutate, a new vaccine has to be made each year, aimed at the flu viruses spreading around that year. More recently, some vaccines are made with pieces of flu DNA, without using eggs.

Being able to quickly turn around a vaccine is becoming more important, Dr. Zimmerman said, particularly with the H3 flu strain, which evolved last year after the vaccine was made.

“It’s a triple-threat virus. It mutates the fastest of all the strains. Second, the virus is virulant; it kills more than the other strains. Third, the egg-based vaccine works the least well.” And sometimes there are two strains of H3, he added.

“H3 is a bear — or a tiger — a threat that we’ve had in the last two years in the U.S.,” Dr. Zimmerman said. The flu has come in two waves, for the past two seasons, he said, with type A flu strains at the