One flu over the chicken’s nest: Difficult flu season reinforces move away from egg-based vaccine manufacture, says GlobalData

After the US Centers for Disease Control and Prevention (CDC) released the stats for the 2017–2018 influenza season, in which there were a reported 97 influenza-related paediatric deaths, GlobalData has reiterated its belief to move away from the traditional chicken egg-based approach of mass production of flu vaccines.

The data and analytics company stated that the traditional egg-based approach to the manufacture of commercial flu vaccines commonly induces a suboptimal immune response. It believes that adoption of more modern mass production methods where vaccines are developed from cell and recombinant vaccine construction technologies should be embraced.

According to GlobalData, there are inherent limitations with the egg-based manufacturing process for vaccines that undermine the potential antibody-antigen binding affinity, which is required to achieve continued vaccine efficacy from season to season. Specific hereditary limitations found in the egg substrate can heighten the antigen differentiation between the vaccine being constructed via the egg and the area of the virus surface protein antigen that is targeted by the vaccine. This results in a lowered binding affinity of the induced antibodies created from a mismatched vaccine.

Egg-based manufacturing processes have been used to develop flu vaccines for more than 70 years (reported by CDC), however, the alternative methods — cell and recombinant — have also been approved for use by regulatory bodies and do not suffer the same limitations found with eggs. Seqirus was approved by the US Food and Drug Administration (FDA) in 2016 as a cell-based flu vaccine manufacturer in the US that uses cell-grown candidate vaccine viruses (CVVs). Its quadrivalent flu vaccine, Flucelvax, is derived from mammalian cells and therefore does not require eggs. The recombinant approach was approved for use by the FDA in 2013 and uses a naturally occurring recommended vaccine virus.

These alternative manufacturing approaches can directly incorporate the sequenced circulating flu viruses and can do so more quickly that the egg-based approach. GlobalData reports that the real-time strain surveillance relationship of this technology can provide the most effective seasonal influenza vaccine.

“In order to best facilitate this shift away from egg-based technology, governments must modernise their partnerships with vaccine manufacturers,” commented Gilbert Saint Jean, PhD, healthcare analyst at GlobalData. “Current surveillance by the World Health Organization (WHO) and other institutions revolves around the 6–8 month egg-substrate vaccine timeline. Overall vaccine efficacy improves with the newer technologies if their quicker manufacturing times are combined with government-provided seed virus submissions from increased surveillance at the global level for mutations in the antigenic target of flu vaccines.”