Houston, Texas, USA: Scientists have developed a new nanoparticle vaccine that provides a promising approach for developing universal influenza vaccines. The double-layered vaccine made with peptides showed strong potential for combating influenza viruses.
The new nanoparticle vaccine could effectively protect mice against influenza A virus, according to a study published on Monday in the Proceedings of the National Academy of Sciences.
Unlike the seasonal flu vaccines that must be updated each year and run the risks of mismatching against pandemic influenza strains, universal flu vaccines can induce broad and effective protection against a wide range of influenza viruses.
The researchers from Georgia State University, Georgia Institute of Technology, Emory University and China’s Henan Normal University resorted to peptides, which are compounds consisting of two or more amino acids linked in a chain.
The nanoparticles mimic the biological cues of viruses and initiate danger signals that activate immune responses, according to the study.
Each double-layered nanoparticle has a core made of peptides from nucleoprotein (NP), an internal influenza protein that has been found to produce cross-protection against influenza virus by inducing T-cell immune responses.
The nanoparticle also has an outside coating made of four peptides from the ectodomain of the influenza A M2 protein (M2e), a promising target for universal flu vaccines. The M2e sequences came from human, swine and avian influenza strains.
They found that mice that received the nanoparticle vaccines completely survived various influenza A virus exposures while all mice that received a placebo died within one week.
“The adaptive immune system includes B lymphocytes mediating antibody responses and T lymphocytes mediating cellular responses,” said Wang Baozhong, senior author of the study and associate professor in the Institute for Biomedical Sciences at Georgia State.
“Our novel nanoparticles trigger immune responses of both immune branches. We have seen the synergistic role of the two branches in providing broad cross-protection against a wide range of diverse influenza virus challenges after vaccination with these layered peptide nanoparticles.”
The peptide-only, double-layered nanoparticles are delivered by skin vaccination with a dissolvable microneedle patch. The microneedle patch is syringe-free, painless, thermostable and self-applicable, according to Wang.
This vaccine approach could also be used to develop vaccines for other pathogens and cancers, Wang said.
EARLIER: Scientists To Begin Tests For World First Universal Flu Vaccine
A universal flu vaccine that would be the first in the world to fight all types of the virus is to be tested, on patients, in a two-year clinical trial by researchers in Oxford University’s Jenner Institute and Vaccitech. Current flu vaccines have to be changed each year to match strains of virus circulating at the time and they do not always protect people that well, especially older patients with weak immune systems. The new jab targets part of the virus that does not change each year. This means the vaccine should work against human, bird and swine flu, say the team at University of Oxford. It will offer people better protection, they believe.
The new universal seasonal flu vaccine works by using proteins found in the core of the virus rather than those on its surface. Surface proteins stick out like pins from the virus and change all the time, while those in the core are stable.
Significantly, the new vaccine works by stimulating the immune system to boost virus-killing T-cells, instead of antibodies. Previous research has shown such T-cells can help fight more than one type of flu virus.
Researchers hope the new vaccine will provide better and longer-lasting protection when used alongside the regular seasonal flu shot.
‘We’re hoping it will last two to three years – maybe even four years – but we really don’t know until we do the trials,’ Vaccitech Chief Executive Tom Evans said. The current trial will take two years to complete. If further studies go well the vaccine could then be licensed for wider use.
The new vaccine has already been tested for safety in earlier trials. Now it is advancing into mid-stage Phase IIb testing, which will see the recruitment of at least 500 British subjects this season. The remainder will be recruited during the 2018/9 flu season.
It is the first time a universal flu vaccine has progressed beyond Phase I clinical testing.
Assuming it is successful in Phase IIb, the new shot will still have to go into much bigger and expensive final-stage testing and Evans said the plan would be to bring in a partner at this stage of development.
‘We would look for a better-capitalised company to take this into final Phase III tests,’ he said.
Leading manufacturers of seasonal flu vaccines include Sanofi, GlaxoSmithKline and CSL’s Seqirus, which includes the old Novartis flu vaccine business.
The seasonal flu vaccine was developed by Oxford University’s Jenner Institute and Vaccitech, a spin-out biotech company founded by Jenner scientists.
It is the world’s first widespread human testing of such a vaccine, according to the National Institute for Health Research, which is supporting the project.
Patients aged 65 or older and living in Berkshire and Oxfordshire will be invited to take part in the trial.
Researchers are seeking about 500 NHS patients to try out a new “universal” vaccine against seasonal flu. Half of the 500 volunteers will receive the usual seasonal flu jab and a placebo or dummy jab, while the other half with get the regular vaccine plus the new experimental one.
Seasonal influenza is an acute viral infection that spreads easily from person to person. Seasonal influenza viruses circulate worldwide and can affect people in any age group. In temperate climates, seasonal epidemics occur mainly during winter while in tropical regions, influenza seasonality is less obvious and epidemics can occur throughout the year. Seasonal influenza is a serious public health problem that causes severe illness and death in high risk populations.
An influenza epidemic can take an economic toll through lost workforce productivity and strained health services.
Influenza vaccination is the most effective way to prevent disease.
Antiviral drugs are available for treatment, though influenza viruses can develop resistance to the drugs.