Changes in Trivalent Flu Shots for 2024-2025 Season: What to Expect

The 2024-2025 flu season is set to bring significant changes to the trivalent flu shots provided by leading vaccine manufacturer, CSL Seqirus. According to recent announcements, the B/Yamagata influenza virus strain will no longer be included in these vaccines. This development holds implications for healthcare professionals, pharmacists, and individuals looking to get vaccinated. What does this mean for the flu season, and how will it affect the effectiveness and distribution of the vaccines?

CSL Seqirus's New Formulation for 2024-2025

CSL Seqirus has announced a change in the formulation of its influenza vaccine portfolio for the 2024-2025 flu season. In a significant move, the B/Yamagata influenza virus strain will be removed from the vaccines distributed in the United States. In the 2023-2024 flu season, over 157 million influenza vaccines were distributed, indicating the extensive reach of these vaccines. The company has been working closely with the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO) to transition from quadrivalent to trivalent influenza vaccines in time for the 2024/25 flu season in the U.S. (source).

Reasons and Implications of Removing the B/Yamagata Strain

The removal of the Yamagata lineage from trivalent flu vaccines is a response to its disappearance since March 2020. The switch from a four flu vaccine to a trivalent one is a complex process, requiring manufacturers to adhere to specific regulatory pipelines. Some manufacturers may need until the 2025-26 season to fully transition to trivalents in the Northern Hemisphere. Major flu vaccine producers such as CSL Seqirus and GSK are on track to deliver trivalent vaccines to the US in time for the 2024-25 flu season if recommended by relevant agencies. Additionally, the removal of Yamagata from flu vaccine recipes should also make them cheaper and improve global access to flu vaccines (source).

Focus on FlucelVax: An Innovative Approach

FlucelVax Quadrivalent QIVc is one of the vaccines offered by Seqirus that is expected to transition to a trivalent vaccine by the 2024-25 flu season. It is a cell culture-based flu vaccine designed to protect against four flu virus strains recommended by the WHO. This vaccine was initially approved by the FDA in 2016 and is indicated for everyone six months and older. The modern manufacturing process allows the flu shot to be antibiotic-free and has been shown to be well tolerated. The cell-based flu vaccines may offer better protection than traditional egg-based flu vaccines. Seqirus is also planning to distribute FlucelVax without the B Yamagata influenza virus strain by the 2024-25 flu season. The company operates a state-of-the-art cell-based manufacturing facility in North Carolina and is constructing a new facility in Melbourne expected to be operational in 2026. A study funded by Seqirus concluded that using QIVc is effective in pediatric patients and is cost-effective. Safety data presented at the ACIP Meeting showed no evidence of safety concerns in pregnant women and the fetus/infant population (source).

The changes to the flu vaccines for the 2024-2025 season reflect the ongoing efforts of manufacturers and health organizations to adapt to evolving virus strains and increase vaccine accessibility. While the removal of the B/Yamagata strain may raise questions, it also promises potential benefits, including cost reduction and improved global access. As the flu season approaches, healthcare professionals, pharmacists, and individuals should stay informed to make the best decisions regarding flu vaccination.