Experimental Universal Vaccine Protects Against 6 Strains of Influenza in Mice

Mouse Getting Vaccination

The flu virus is ever-evolving. The annual flu shot available each fall only protects against certain strains of the virus and, even then, is no guarantee of prevention. However, new research from Georgia State University is showing promise as a potential universal vaccine against influenza.

While the research has only been conducted on mice, scientists from the university say their work is yielding positive results. The experimental vaccine is providing broad, long-lasting protection against influenza virus in mice, the university announced this week. The researchers are experimenting with a novel nanoparticle vaccine that combines two major influenza proteins. The vaccine contains the influenza virus proteins matrix protein 2 ectodomain (M2e) and neuraminidase (NA), the university said. M2e is found in all influenza virus strains and remains similar within those strains. The protein NA is found on the surface of the influenza virus and has also mutated much slower than other influenza proteins, the researchers said.

When it was injected into the mice subjects, the vaccine protected the animals against six different strains of the virus. Current flu vaccines in use in the United States protect against three or four strains, according to the U.S. Centers for Disease Control and Prevention. The CDC reported the overall vaccine efficacy for the 2016-2017 flu season was 20% across all virus strains.

With the success of the vaccine in the mice, the GSU scientists believe the vaccine combination has the potential as a universal flu vaccine. The research was published in the journal Advanced Healthcare Materials.

Ye Wang, the first author of the study, said the nanoparticle antigen combination provided the mice with strong cross-protection of the influenza strains. The immune protection was seen in the mice for up to four months, the study showed. Wang said it can protect the mice from the different strains and, through the use of this approach, it has the potential to protect people as well.

Gilbert Gonzales, a co-author of the study, said most flu vaccines have not focused on neuraminidase (NA) before due to the greater focus on hemagglutinin (HA).  Gonzales said the body reacts to HA when the flu virus attacks it. But, NA is becoming a “more important antigen for influenza vaccine research,” Gonzales said.

The problem with focusing on HA, the GSU team notes, is that it rapidly mutates, which makes it difficult to target. As the GSU researcher said, someone could get the flu this year and develop immunity against that particular HA protein, but by next flu season, the HA protein would have rapidly changed and they wouldn’t be protected again.

The GSU team isn’t the only group focused on improving flu vaccines. In December, Seqirus released new data that shows Fluad, an adjuvanted trivalent influenza vaccine, was more effective than standard non-adjuvanted trivalent influenza vaccine in reducing the risk of flu- and pneumonia-related hospitalization in patients 65-years-of-age and older. Last year, the National Institutes of Health (NIH) began its own program aimed at developing a universal vaccine that is currently enrolling in a Phase I trial. According to the NIH, the experimental vaccine known as H1ssF_3928  is designed to “teach the body to make protective immune responses against diverse influenza subtypes by focusing the immune system on a portion of the virus that varies relatively little from strain to strain.” Massachusetts-based Versatope Therapeutics received a leg up in its universal vaccine development efforts at the end of September with a $17.9 million grant from the National Institute of Allergy & Infectious Diseases.

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