Scientists could be on the brink of a 'universal' flu vaccine

Scientists have taken a step towards creating a universal flu vaccine by targeting short fragments of the virus common to all strains

08 Oct 2016
Lancaster University

It is one of the starkest reminders of the power of evolution, and in the arms race between medicine and influenza, humans don't always win.

As winter approaches, millions of people are given a vaccination to protect them against flu – a minor inconvenience to ward off a potentially lethal disease. But each year the flu virus mutates, and a vaccine against one strain is basically useless against any other.

Now scientists at Lancaster University believe they have solved the problem of creating a universal flu vaccine. Instead of targeting a specific strain of virus, they have focused on the epitopes – short fragments of the flu virus that are common to all strains.

However, each strain also has multiple subtypes. In the winter of 2014-2015, the vaccine selected was effective against Influenza A(H1N1)pdm09, as well as Influenza B, but the predominant strain circulating in the wild was a type of H3N2 virus.

As a result the vaccine was effective in only about 3 per cent of people in the UK that season, compared to about 50 per cent in usual circumstances.

Types of flu strains

There are three main types of flu virus: Influenza A, B, and C, and existing vaccines usually target three or four specific strains within this range.
Type A is of the most concern, and can be carried by humans and some animals including birds, pigs, and horses.
Type B are human only, usually less severe, and never cause pandemics. Type C are less dangerous still.
Within type A are multiple strains, labelled by the numbers of the two glycoproteins hemagglutinin (H) and neuraminidase (N) to give a specific identifier such as H1N1 or H3N5. The H number can be up to 16, while the N number can be up to 9, giving 144 primary varieties of Type A virus.

The epitope approach to a universal flu vaccine has been suggested before, but Dr Derek Gatherer of Lancaster University said recent advances in computational medicine give it a better chance of success: "We can use computers to design the components of a vaccine that gives much broader and longer-lasting protection."

Working with colleagues at Aston University, and Complutense in Madrid, Dr Gatherer has designed two universal vaccines – one of which would protect against 95 per cent of flu strains in the USA, the other against 88 per cent globally.


But why is the US population used as the benchmark?

"It’s just a technical thing", Dr Gatherer told WIRED, "to do with the databases we work with. Because the US population is slightly less diverse than the world as a whole (although of course still one of the most diverse countries) the result is different."

The epitope-inspired vaccine remains a computer design only for the time being, but Dr Gatherer's team is actively seeking a pharmaceutical industry partner to synthesise the molecule for a laboratory test.

He is optimistic: "We think our design has a better chance than other universal vaccines that have performed poorly in the past. Quite what that chance is, however, remains to be seen."

Dr Gatherer believes that evolution will still allow the virus to get around the vaccine – "but this would take decades. Currently, vaccines are obsolete within a year or so."