35 - FLU VACCINES - Influenza – the risk to vulnerable populations

Looking back on the 2021-22 flu season, those of us dedicated to fighting flu can reflect on the past two years with mixed feelings. First, we can feel gratitude that some of the measures put in place to fight COVID-19 also led to far fewer cases of influenza over the past two years. In fact, the 2020-21 flu season activity was remarkably low, partly due to masking and social distancing measures implemented to fight the COVID-19 pandemic.

There is cause for some concern, however, as low flu activity over the past two seasons is driving complacency around vaccination. In the 2021-22 season, significantly fewer people than last year took the necessary precaution of getting their flu shot, contrasting with a record number of people getting a flu shot in the 2020-21 season. The 2022-23 flu season will have few people wearing masks and little social distancing, which is all the more reason why we need to leverage every tool available to fight flu, prioritise public health and strengthen vaccine confidence for next flu season and beyond.

This need is particularly important for more vulnerable populations – like those aged 65 years and older – who are at higher risk for serious complications, hospitalisations or even death from flu. Combined with the ongoing threat of COVID-19, there is a greater-than-ever need to protect the 65+ population while at the same time eliminating the burden on the healthcare system.

Thankfully, one of those tools available to help combat this threat is the availability of Enhanced Influenza Vaccines (EIVs) which are ‘enhanced’ formulations of flu vaccines that were designed to offer a more robust immune response to the flu vaccine in those 65 and older.

In the US, the Advisory Committee on Immunization Practices acknowledged that there was evidence of benefit favouring each of the enhanced influenza vaccines over standard dose vaccines: Flublok Quadrivalent (Influenza Vaccine) and Fluzone High-Dose Quadrivalent (Influenza Vaccine) by Sanofi Pasteur and Fluad Quadrivalent(Influenza Vaccine, Adjuvanted) by CSL Seqirus UK. Fluad Quadrivalent contains an adjuvant called MF59 that is added to the vaccine to help boost the immune response to vaccination.

In the US, the Advisory Committee on Immunization Practices (ACIP), which is an advisory committee to the Centers for Disease Control and Prevention (CDC) on vaccine-preventable diseases, voted to preferentially recommend the EIV category for the 65+ population.

Data presented at ACIP’s February meeting showed that the overall evidence directly comparing EIVs with one another – based on data including millions of patients and multiple seasons – does not indicate superiority of one EIV over the others.

At CSL Seqirus, we support the public health benefit of an EIV category recommendation for older adults. We are confident in ACIP’s process and the expertise of those on the advisory committee, and we remain committed, as part of a larger industry, to delivering a multitude of safe and effective flu vaccine options for people of all ages, so that as many people as possible are protected against flu each year.

I want to stress here that vaccine manufacturers have a special obligation to improve public confidence in vaccines by educated against complacency – sharing our own expertise and fact-based information with the public. Every stakeholder in this battle against flu should be united in that goal, so that we protect as many people as possible from the burden of influenza.