A vaccine combining centralized ancestral genes from four major influenza strains appears to provide broad protection against the dangerous ailment, according to new research by a team from the Nebraska Center for Virology.
Mice protected by the unconventional vaccine survived exposure to lethal doses of seven of nine widely divergent influenza viruses. Those that received higher doses of the vaccine didn’t even get sick.
In contrast, mice that received traditional flu shots or nasal sprays all sickened and died when exposed to the same viruses. The deadly pathogens were able to evade the immune responses triggered by the traditional vaccines.
While it is too soon to say the approach could be successfully used in humans, it appears to be a promising avenue toward a universal flu shot, according to lead researcher Eric Weaver, an assistant professor in the School of Biological Sciences at the University of Nebraska-Lincoln.
Weaver said the study is the first to report on whether a universal flu shot could be created by using a combination of multiple genes shared at the ancestral level by flu strains circulating today.
“The ultimate goal is to be able to vaccinate once and provide lifelong protection,” Weaver said.
The Centers for Disease Control and Prevention estimates that 40 million Americans contracted influenza during the 2015-16 flu season and 970,000 people were hospitalized for the ailment. The agency estimated that vaccinations prevented about 1.9 million illnesses and 67,000 hospitalizations.
“To put this in other terms, our current influenza vaccine programs and technologies reduce influenza infections and hospitalizations by 4.75 percent and 6.9 percent, respectively,” Weaver said. “There is no doubt that there is a need for more effective vaccine technologies.”
Yet because the influenza virus mutates rapidly and because people, animals and birds often carry the virus without displaying symptoms, it’s been difficult to develop a vaccine with long-term effectiveness. The conventional influenza vaccine platform uses weakened or dead versions of the influenza virus to stimulate immunity against hemagglutinin (HA), a spike-shaped protein that extends from the surface of the virus and attacks cells.
According to a 2013 Clinical Microbiology Reviews article, the challenges of the conventional approach include predicting which flu strain will circulate in coming years; manufacturing and delivering safe, timely and adequate supplies; and poor responsiveness among the elderly, who often are the most vulnerable to influenza infection.
Conventional vaccines have been shown to be less than 60 percent effective when they’re successfully matched to the currently circulating strain. They’re far less effective when mismatched.
“An ideal influenza vaccine would be inexpensive, provide long-lasting immunity, require few immunizations and would work against all variants of the virus,” Weaver said.
Some experts say it could take until 2020 or 2025 before a universal flu vaccine is available.
Pursuit of a universal influenza vaccine has been difficult. Scientists are trying various approaches to better match vaccines to multiple viral strains. Other strategies include developing vaccines aimed at the virus’s protein coat, other proteins that have been found to be identical in multiple flu strains, or the stalk of the hemagglutinin protein rather than its head.
These approaches have shown promising results. However, Weaver said his study is the first to report the use of multiple centralized HA genes, identified using protein sequence analysis programs, to provide the greatest level of cross-protective immunity possible.
In the article published Nov. 2 in Scientific Reports, Weaver and his colleagues Amy Lingel and Brianna L. Bullard detail an approach they say is “scalable and translatable to humans and may provide the foundation for complete and long-lasting anti-influenza immunity.”
The idea arose from past research led by Dr. Bette Korber at Los Alamos National Laboratories to discover the ancestral genes for the Human Immunodeficiency Virus and to pinpoint when that virus jumped from monkeys to man. Weaver was involved with that effort while a post-doctoral researcher at Duke University School of Medicine. He and his colleagues decided to try a similar concept with the influenza virus, synthesizing genes that are central to influenza’s phylogenetic tree.
Instead of using weakened or deadened flu virus, his experiments at the Nebraska Center for Virology have used replication-defective Adenoviruses – which cause the common cold – that have been altered to carry what he calls consensus genes for H1, H2, H3 and H5 influenza strains. The vaccine is no longer capable of causing cold symptoms, but is still able to safely deliver the influenza vaccine genes.
“Our idea is that these centralized antigens can set up a foundation of immunity against influenza,” he said. “Because they are centralized and represent all the strains equally, they could provide a basis for immunity against all evolved strains.”
The Latest on: Flu vaccine
- Coronavirus: NRL offered flu vaccine exemption in Queensland, but only for medical reasonson May 11, 2020 at 6:51 pm
Gold Coast Titans pair Bryce Cartwright and Brian Kelly have been stood down after refusing to get the flu vaccine ahead of the NRL restarting its season on May 28. While New South Wales has allowed ...
- Influenza Diagnostics Market 2019 Global Size, Opportunities, Historical Analysis, Development Status, Business Growth and Regional Forecast To 2026on May 11, 2020 at 5:59 am
Global Influenza Diagnostics Market is valued approximately at USD 646.5 million in 2019 and is anticipated to grow with ...
- Scarlet fever, diphtheria, polio: How the 1918-19 influenza pandemic shaped the way Alaskans faced other outbreakson May 10, 2020 at 7:32 pm
Most Alaska communities, including Anchorage, only established organizations like boards of health with the arrival of that pandemic in 1918.
- Coronavirus: Flu vaccine NRL's decision in New South Waleson May 10, 2020 at 6:06 pm
New South Wales chief health officer Dr Kerry Chant said it was up to the NRL whether it wanted its players to have a flu vaccination. Queensland has told the NRL its players would need a flu shot to ...
- Easing social distancing too soon during 1918 influenza pandemic led to second deadly wave in St. Louison May 9, 2020 at 8:33 pm
If history repeats itself, could we expect to see a second and third wave of the disease, just as St. Louis did during the deadly influenza outbreak of 1918?
- Ashland Memories: Influenza brought spike in local deaths in October 1918on May 9, 2020 at 12:52 am
Ashland saw a notable spike in deaths in a single month during the influenza pandemic of 1918. From 20 deaths in September 1918, total deaths in the ...
- Coronavirus: NSW health minister tells NRL to 'stick to the deal' over flu vaccineon May 8, 2020 at 9:30 pm
As debate continues around the flu vaccination, New South Wales health minister Brad Hazzard had a message for the NRL.
- Monocyte apoptotic bodies are vehicles for influenza A virus propagationon May 8, 2020 at 2:41 am
Smith et al. study apoptotic bodies formed when Influenza A (IAV)-infected monocytes undergo apoptosis. They find that apoptotic bodies contain components of IAV and can contribute to IAV propagation ...
- Flu Vaccine Market Outlook 2024: United States Opportunity and Demand Analysis, Market Forecast 2017-2024on May 7, 2020 at 5:37 am
United States flu vaccine market is expected to reach nearly US$ 3 Billion by 2024. Growth in US flu vaccine market can be ...
- Triple combination therapy of favipiravir plus two monoclonal antibodies eradicates influenza virus from nude miceon May 7, 2020 at 2:22 am
Prolonged treatment of immunocompromised influenza patients with viral neuraminidase (NA) inhibitors is required, because the immune system of such patients fails to eradicate the viruses. Here, we ...
via Google News and Bing News