Every year the flu virus emerges in a different way.therefore need Adapting flu vaccine to virus serotypes circulating each season.According to the World Health Organization (WHO), the factors that cause seasonal epidemics are virus A – the subtypes currently circulating in humans are (H1N1) and A(H3N2) – which are responsible for all known epidemics, and B virus – Not divided into subtypes, but those currently in circulation are divided into B/Yamagata and B/Victoria lineages.
Therefore, implementing a Universal Flu Vaccine This is almost required. That goal is getting closer, as some countries, such as Australia or the United States, have begun trials looking for vaccines that cover multiple strains of the flu.
First human trial in the U.S.
In the U.S., early results from first-in-human trials Vaccines cover multiple variants Influenza was a complete success.
A phase I open-label clinical trial is testing a HA-stabilized dry ferritin nanoparticle (H1ssF) vaccine based on H1 HA from A/New Caledonia/October 1999.in the study participated in 52 healthy adults aged 18 to 70, received a single dose of 20 μg H1ssF or two doses of 60 μg H1ssF with a booster interval of 16 weeks. Of these, 35 (74%) participants who received the 60 μg dose received a booster shot, while 11 (23%) missed the booster shot due to public health restrictions in the early stages of the COVID-19 pandemic.
“Influenza vaccines could be improved by inducing platforms cross reactive immunity. The immunodominance of influenza hemagglutinin (HA) tau in currently licensed vaccines prevents induction of cross-reactive stem-directed neutralizing antibodies. Vaccines without variable HA head domains have the potential to focus the immune response on the conserved HA stalk,” explained the trial authors.
According to data published in Science, H1ssF It was safe and well tolerated, requiring mild local and systemic reactogenicity. The most common symptoms include pain or tenderness at the injection site, headache, and discomfort.
“We found that H1ssF causes Cross-reactive neutralizing antibody against dry HA Despite preexisting head-specific immunity to the H1 subtype, it remains immune to influenza virus.These responses were long-lasting, with neutralizing antibodies observed more than a year after vaccination,” the authors note. In this way, the results support the platform as Development of universal flu vaccine ‘a step forward’.
Australia’s promising universal vaccine
Australia, on the other hand, launched last May Universal Vaccine Trial Fight the flu. Brisbane’s Mater Hospital has started a study of the OVX836 flu vaccine, initially including 180 volunteers aged 18 to 60, although it is expected to reach 600 in other parts of the country, ABC News reported.
this vaccine It targets the nucleoprotein of the virus., which is an element that is not easily mutated. The trial compared three vaccine combinations: OVX836 vaccine versus conventional vaccine, OVX836 versus placebo, and conventional vaccine versus placebo. This phase of the trial is expected to be completed by the end of this year in 2023. If satisfactory, it will move to a third phase, involving thousands of volunteers.
If such a vaccine is approved, it will help increase influenza vaccination coverage.In addition, a universal vaccine has been developed against Paul GriffinThe director of infectious diseases at Mater Hospital said he could “revolutionize the way people protect themselves from flu infection”. Target parts of the virus that don’t change“.
While trial results are still preliminary and inconclusive, Griffin is optimistic that the vaccine can Over the past few yearswhich would represent a huge advance in the field of influenza prevention.