Universal flu vaccine: what is new mRNA jab that could protect against 20 strains of influenza?

Could we be a step closer to a universal flu vaccine?

A potential universal flu vaccine has been found to be effective against 20 strains of influenza.

The vaccine has been developed by researchers at the University of Pennsylvania in the US. It is a step towards the development of a true universal flu vaccine.

At the current time, the vaccines issued each winter are tailored to specific influenza strains. However a universal vaccine would cover all of the strains.

It would likely reduce the chance of an ineffective vaccine being disrubuted annually, as researchers can occasionally select the wrong strain to target. A universal vaccine would provide protection from the full range.

But what is a universal flu vaccine, what technology is used to develop it and why has it been so difficult to develop? Here is all you need to know:

What is a universal flu vaccine?

A universal flu vaccine would do exactly what the name says on the tin. It would be effective against any strain of the influenza virus that can infect humans.

New Scientist reports that an experimental mRNA vaccine has generated antibody responses against 20 strains of flu in tests on animals. It raises the hope that a universal flu vaccine could be possible.

During the tests, Scott Hensley at the University of Pennsylvania and his colleagues used the vaccine on mice. The team found that the generated antibodies specific to all 20 strains of the flu virus and they remained at a stable level for up to four months.

New Scientist wrote: “All the mice given the flu vaccine survived exposure to the virus with the more similar protein and 80 per cent survived being infected with the more distinct variant. All of the mice given the dummy vaccine died around a week after infection with either variant.

“Another group of mice were given an mRNA vaccine targeted only to the precise flu strain they were exposed to, and all of this group survived over the same time period.”

Albert Osterhaus at the University of Veterinary Medicine Hannover in Germany, who wasn’t involved in the study, warned that the above finding could mean that the universal flu vaccine could prove to be less effective against new variants of the 20 flu strains than an annual vaccine matched to new forms of the virus.

People are being urged to get their Covid and flu vaccines this winter

What is mRNA?

The abbreviation mRNA stands for messenger ribonucleic acid. The National Human Genome Research Institute explains that it is “a type of single-stranded RNA involved in protein synthesis”.

“mRNA is made from a DNA template during the process of transcription,” the NHGRI continues. “The role of mRNA is to carry protein information from the DNA in a cell’s nucleus to the cell’s cytoplasm (watery interior), where the protein-making machinery reads the mRNA sequence and translates each three-base codon into its corresponding amino acid in a growing protein chain.”

Moderna used mRNA technology for its Covid-19 vaccine.

Why is a universal flu vaccine so hard to develop?

New flu vaccines are issued each winter to help during the spread of seasonal viruses. The reason that fresh doses have to be delivered each year is because influenza viruses are constantly evolving.

The vaccines produced annually are currently tailored for specific strains but not the full range of variants and predict which strains might be more prevelant that year. Researchers have in the past picked the wrong strains and it can result in a less effective vaccine.

Because of the constant evolving of influenza strains, it has made the search for a universal flu vaccine a difficult task for researchers.

When could universal flu vaccine be ready for human use?

Professor John Oxford, a virologist at Queen Mary University in London, said a new vaccine developed at the University of Pennsylvania represented a “huge breakthrough”. Prof Oxford told the BBC Radio 4 Today programme: “I cannot emphasise enough what a breakthrough this paper is,” and there was a “very good chance”.

He said about 30 or 40 volunteers would be needed for a phase 1 clinical trial, with the first data possibly coming within the next six months. Prof Oxford said the jab could save thousands of lives.

Prof Oxford said that the vaccine could be ready for human use in two years.