Each year, millions worldwide contract influenza, commonly known as the flu. While many recover swiftly, the flu can be deadly, especially for older adults, young children, and those with weakened immune systems. In the UK alone, seasonal flu can result in thousands of deaths during severe outbreaks. This underscores the critical importance of having an effective and up-to-date flu vaccine.
As millions prepare for seasonal influenza by getting vaccinated, the process might seem straightforward—a quick jab at the local GP or pharmacy. However, behind the scenes, ensuring that the vaccine is ready, safe, and effective involves months of international planning, testing, and collaboration.
At the heart of this global effort is the Medicines and Healthcare products Regulatory Agency (MHRA), the UK’s regulator for medicines and medical devices. The MHRA’s influence extends beyond approving medicines for the UK; it plays a pivotal role on the international stage by hosting the MHRA Global Influenza Meeting, a key event that guides the development and delivery of the world’s flu vaccines.
Why the Flu Vaccine Needs Annual Updates
Unlike some viruses, such as measles, the influenza virus constantly changes and evolves. This means that last year’s vaccine may not protect against this year’s strains. Each year, scientists and regulators worldwide collaborate to track the latest virus strains and decide which should be included in the next season’s vaccine.
The World Health Organization (WHO) leads this process through a network of research centers and laboratories known as the Global Influenza Surveillance and Response System. However, transforming scientific research and development into safe, effective, and timely licensed vaccines requires regulatory oversight. The MHRA plays a crucial role in these efforts.
A Meeting Two Decades in the Making
This year marks the 40th MHRA influenza meeting, held twice annually for the past 20 years. The latest meeting took place last week. What began as a European-focused gathering has evolved into a major global event, drawing public health experts, scientists, manufacturers, and regulators from around the world.
As Dr. Othmar Engelhardt, the MHRA’s Head of Seasonal Influenza and the meeting organizer, explains, the MHRA provides “a well-established venue for discussions within the community, bringing together everyone involved in the process of producing and delivering the vaccine after the strains relevant to a particular season are recommended by the WHO strain selection committee.”
What Happens at the Meeting?
The meeting aims to ensure all stakeholders have the information needed to provide the best possible annual flu vaccine—delivered on time, with minimal obstacles. It’s a forum to share scientific insights, streamline processes, and keep the world prepared.
- Update on influenza worldwide: Which flu viruses are circulating globally, and which are most likely to pose a threat in the coming season?
- Reagents and standards: What laboratory materials are available for testing and manufacturing? How can the community expedite access to these materials?
- Vaccine production updates: How prepared are manufacturers for the upcoming flu season following the WHO strain recommendation, and what’s needed to smooth the supply chain?
Importantly, there is also a focus on zoonotic influenza—flu viruses that jump from animals, such as birds or pigs, to humans. These have the potential to spark the next influenza pandemic, making surveillance and preparation of potential vaccine candidates essential.
The Disappearance of B/Yamagata
One notable scientific development in recent years is the apparent disappearance of the B/Yamagata flu lineage since the COVID-19 pandemic. Previously, flu vaccines were quadrivalent, containing four virus components (two A types and two B types). Now, many have shifted to a trivalent vaccine, with only three components—a change that required regulatory review and approval.
Special Topics: New Vaccines and Testing Methods
Day three of the meeting was dedicated to a special topic, specifically a workshop on new vaccine platforms and targets for influenza. As technology evolves, researchers are exploring faster and potentially more effective ways to develop, test, and produce vaccines, including using mRNA technology and exploring universal flu vaccines that wouldn’t need to change between seasons.
Another key area is vaccine potency (i.e., dose) testing. The current gold-standard method, called Single Radial Immunodiffusion (SRD), was developed in the 1970s by the National Institute for Biological Standards and Control (NIBSC), now part of the MHRA. Though still recommended by the WHO, researchers are now working on faster and more flexible alternatives, supported by a working group that reports back into the MHRA meeting.
The 40th meeting also featured reflections from former NIBSC/MHRA staff who were key contributors to SRD methodology, underscoring the UK’s longstanding leadership in this space.
MHRA’s International Role
As one of the four WHO Essential Regulatory Laboratories (ERLs)—alongside labs in the US, Japan, and Australia—the MHRA plays a unique role. Its Influenza Resource Centre (IRC) helps develop candidate vaccine viruses (CVVs), ships CVVs and reagents worldwide, contributes scientific expertise to vaccine strain selection, prepares biological standards and reagents for vaccine manufacture and testing, and advises on the global regulatory process.
This role also places the MHRA at the forefront of pandemic preparedness, including contributing to the WHO’s Pandemic Influenza Vaccine Preparedness framework. This involves staying alert to emerging zoonotic threats and ensuring the global community is ready to respond.
A Diverse and United Audience
What makes the MHRA Global Influenza Meeting especially valuable is its diversity. It brings together the WHO, regulators, researchers, and manufacturers in one open forum. In a field as complex and fast-moving as influenza, open communication is vital.
As Dr. Engelhardt noted, “The flu field can be difficult because the viruses change all the time, meaning that the vaccines have to change as well.” The meeting provides a rare opportunity for all the key players to align their goals, share progress, and prepare together.
Why It Matters to the UK and the World
Ultimately, the MHRA’s role in facilitating this global collaboration helps ensure that flu vaccines are timely, safe, and effective, not just in the UK but globally. From setting scientific standards to hosting crucial conversations, the MHRA continues to play a central role in protecting global health.
For the UK, this means protection each winter. For the global community, it means stronger defenses against one of the world’s most common infectious threats. So next time you’re offered a flu vaccination, remember that behind that quick appointment lies a year of global planning, science, and collaboration—with much of this happening right here in the UK.
