Some flu shot shipments will be delayed

August 21, 2019

Flu vaccines manufactured by Sanofi Pasteur will be delayed a few weeks, but should still arrive in time to provide protection for the season.

Shipments will be delayed for some flu vaccines, but the delays aren’t expected to create any overall shortages.

The delayed shipments apply to flu vaccines produced by Sanofi Pasteur, which sent letters to healthcare providers announcing the issue in late June. The delay will push out the starting point to start flu vaccinations for the year, but vaccines should still arrive in plenty of time to keep patients protected for the flu season, according to company officials.

“We are still on track to produce approximately 70 million doses of seasonal vaccine to support nationwide immunization campaigns,” said Michael Szumera, head of U.S. communications for Sanofi Pasteur.

The company anticipates roughly a one-month delay in the first shipment of the vaccine, with shipments beginning in mid-August. All shipments should be completed by the end of November, Szumera said. Patients are generally recommended to be vaccinated for the flu by the end of October, as vaccines take two weeks to offer protection, according to the Centers for Disease Control and Prevention (CDC). The flu season typically peaks between December and February.

The delay was caused by the World Health Organization (WHO) postponing its selection of the influenza A (H3N2) strain to be included in the vaccine for the Northern Hemisphere by one month after observing antigenic drift in the circulating strain, Szumera said.

“This allowed health authorities to collect additional data to improve the match of the vaccine strain to the A (H3N2) strain anticipated to circulate during the 2019-2020 season,” he said. “Manufacturing could not begin until the selection was made by WHO and confirmed by the U.S. Food and Drug Administration.”

The delay will affect all three Sanofi Pasteur vaccines-Fluzone Quadrivalent, Fluzone High-Dose, and Flublok Quadrivalent. Sanofi Pasteur’s flu vaccines make up about 40 percent of the U.S. flu vaccine supply, according to data from the Centers for Disease Control and Prevention (CDC).

“As the single largest provider of flu vaccine to the United States, we support this decision and are committed to delivering millions of flu vaccine doses for the upcoming season,” Szumera said.

Other flu vaccine manufacturers have not announced delays, but AstraZeneca has warned that FluMist Quadrivalent supplies will be limited this year due to manufacturing constraints.

Clinicians who have questions about their vaccine orders should contact their distributor, and Szumera said questions specific to the Sanofi delay can call (800) 822-2463.