Sanofi Pasteur has shipped the first of its flu vaccines for the 2018-2019 season, with plans to make about 70 million doses.
The 70 million total is about the same as the French vaccinemaker had planned for the 2017-18 flu season, but this season, the company will increase supplies of Flublok Quadrivalent and Fluzone High-Dose to 25 million doses.
Sanofi obtained Flublok Quadrivalent, the only FDA-approved recombinant protein-based flu vaccine, through its Protein Sciences acquisition last year. Grown in insect cells, these vaccines offer a more accurate match of hemagglutinin from the recommended vaccine virus strains.
In a study from Protein Sciences published last June in The New England Journal of Medicine, Flublok lowered the probability of flu-like illness by about 30% in people aged 50 years or older compared to traditional egg-based vaccines.
Fluzone High-Dose, made in eggs with larger amount of antigen intended to elicit a stronger immune response, is specifically meant for adults 65 or older. Sanofi Pasteur expects that two-thirds of all eligible seniors who will get a flu shot in the U.S. will receive Fluzone High-Dose.
Seniors are at higher risk of developing flu-related complications that could lead to hospitalizations or deaths. In the past H3N2-predominated flu season, flu vaccines on average didn’t perform very well and were only 18% effective in adults 65 years of age or older, a CDC interim analysis found.
“This past flu season was a stark reminder of how unpredictable flu can be. It is important to get vaccinated even if vaccine effectiveness is lower than we would like,” said David Greenberg, M.D., Sanofi Pasteur’s North America regional head, in a statement.
Recent studies have put the widely adopted egg-based flu vaccine production process in question because when grown in eggs, flu viruses go through genetic mutations that could leave the final product less effective. An FDA real-world analysis based on 2017-18 season’s data from over 13 million Medicare beneficiaries showed that, compared to traditional egg-based vaccines, Seqirus’ cell-cultured quadrivalent flu shot Flucelvax worked 10.7% better at keeping those 65 and older out of the hospital, while Fluzone High-Dose was 8.4% more effective.
Sanofi is the world’s largest flu vaccine provider. Last year, over 70% of Sanofi’s €1.59 billion ($1.91 billion) flu vaccines sales came from the U.S. According to the company’s annual report, impacts from the Protein Sciences buyout and Flublok sales were insignificant for 2017.