
via Perelman School of Medicine
Promising results in animal models help pave the way for clinical trials
An experimental mRNA-based vaccine against all 20 known subtypes of influenza virus provided broad protection from otherwise lethal flu strains in initial tests, and thus might serve one day as a general preventative measure against future flu pandemics, according to researchers from the Perelman School of Medicine at the University of Pennsylvania.
The “multivalent” vaccine, which the researchers describe in a paper published today in Science, uses the same messenger ribonucleic acid (mRNA) technology employed in the Pfizer and Moderna SARS-CoV-2 vaccines. This mRNA technology that enabled those COVID-19 vaccines was pioneered at Penn. Tests in animal models showed that the vaccine dramatically reduced signs of illness and protected from death, even when the animals were exposed to flu strains different from those used in making the vaccine.
“The idea here is to have a vaccine that will give people a baseline level of immune memory to diverse flu strains, so that there will be far less disease and death when the next flu pandemic occurs,” said study senior author Scott Hensley, PhD, a professor in of Microbiology at in the Perelman School of Medicine.
Hensley and his laboratory collaborated in the study with the laboratory of mRNA vaccine pioneer Drew Weissman, MD, PhD, the Roberts Family Professor in Vaccine Research and Director of Vaccine Research at Penn Medicine.
Influenza viruses periodically cause pandemics with enormous death tolls. The best known of these was the 1918-19 “Spanish flu” pandemic, which killed at least tens of millions of people worldwide. Flu viruses can circulate in birds, pigs, and other animals, and pandemics can start when one of these strains jumps to humans and acquires mutations that adapt it better for spreading among humans. Current flu vaccines are merely “seasonal” vaccines that protect against recently circulating strains, but would not be expected to protect against new, pandemic strains.
The strategy employed by the Penn Medicine researchers is to vaccinate using immunogens—a type of antigen that stimulates immune responses—from all known influenza subtypes in order to elicit broad protection. The vaccine is not expected to provide “sterilizing” immunity that completely prevents viral infections. Instead, the new study shows that the vaccine elicits a memory immune response that can be quickly recalled and adapted to new pandemic viral strains, significantly reducing severe illness and death from infections.
“It would be comparable to first-generation SARS-CoV-2 mRNA vaccines, which were targeted to the original Wuhan strain of the coronavirus,” Hensley said. “Against later variants such as Omicron, these original vaccines did not fully block viral infections, but they continue to provide durable protection against severe disease and death.”
The experimental vaccine, when injected and taken up by the cells of recipients, starts producing copies of a key flu virus protein, the hemagglutinin protein, for all twenty influenza hemagglutinin subtypes—H1 through H18 for influenza A viruses, and two more for influenza B viruses.
“For a conventional vaccine, immunizing against all these subtypes would be a major challenge, but with mRNA technology it’s relatively easy,” Hensley said.
In mice, the mRNA vaccine elicited high levels of antibodies, which stayed elevated for at least four months, and reacted strongly to all 20 flu subtypes. Moreover, the vaccine seemed relatively unaffected by prior influenza virus exposures, which can skew immune responses to conventional influenza vaccines. The researchers observed that the antibody response in the mice was strong and broad whether or not the animals had been exposed to flu virus before.
Hensley and his colleagues currently are designing human clinical trials, he said. The researchers envision that, if those trials are successful, the vaccine may be useful for eliciting long-term immune memory against all influenza subtypes in people of all age groups, including young children.
“We think this vaccine could significantly reduce the chances of ever getting a severe flu infection,” Hensley said.
In principle, he added, the same multivalent mRNA strategy can be used for other viruses with pandemic potential, including coronaviruses.
Original Article: Penn Scientists develop 20-subtype mRNA flu vaccine to protect against future flu pandemics
More from: Perelman School of Medicine at the University of Pennsylvania
The Latest Updates from Bing News
Go deeper with Bing News on:
Multivalent vaccine
- Research demonstrates ability of thermostable nanoparticle design platform to tackle viral infections
New research has demonstrated the potential for the ADDomer platform to produce thermostable vaccines and reagents to tackle viral infections The study led by the University of Bristol and Imophoron, ...
- Vaccines News
Nov. 8, 2023 — The most effective way to prevent cervical cancer is to give HPV vaccines to both boys and girls, reports a collaborative study. Beside personal immunity, such use of the vaccine ...
- You can get Covid-19 and flu vaccines at the same time, but should you? What the science says
With holiday season underway, you may be realizing that you forgot to get your Covid-19 and flu vaccines, and now you’ll be sitting across the table from your elderly relatives. The good news is ...
- What You Should Know About the 2024 Adult Vaccine Schedule
Notable changes to the 2024 adult immunization schedule include updated recommendations for the RSV, mpox, meningococcal, and COVID-19 vaccines. When you go to your healthcare provider next year, you ...
- A Cancer Vaccine? Scientists are Working on It
One of the most exciting developments are cancer vaccines. Scientists are using artificial intelligence to identify mutations in cancerous tumors that the immune system can recognize, then ...
Go deeper with Bing News on:
mRNA flu vaccine
- Study estimates 2 COVID vaccine doses 40% effective against emergency, hospital care in young kids
Two doses of a COVID-19 mRNA vaccine were 40% effective against emergency department (ED) visits and hospitalization in preschool-aged children during a period of Omicron variant predominance, ...
- CSL & Arcturus Therapeutics' self-amplifying mRNA vaccine, ARCT-154 receives Japanese approval for Covid in adults
CSL's vaccine business, CSL Seqirus, one of the largest influenza vaccine providers in the world, partnered exclusively with Meiji Seika Pharma for distribution of the sa-mRNA Covid vaccine, ARCT 154, ...
- Japan approves first self-amplified mRNA vaccine
Japan’s regulators have approved ARCT-154, a COVID-19 vaccine based on self-amplified messenger RNA (sa-mRNA) technology.
- 20Med Therapeutics Appoints Industry Veteran Hugo Fry as Chief Business Officer to Expedite mRNA Vaccine Delivery Platform Program
Hugo_Fry_by_Barry_Braunstein_Photography Hugo Fry, Chief Business Officer, 20Med Therapeutics Leiden, The Netherlands, November 29, 2023 – 20Med Therapeutics, a leader in non-viral delivery of mRNA ...
- Australia's blood banks not 'tainted' by Covid-19 vaccines: experts
"Any mRNA from vaccines is also rapidly broken down and does not ... "Similar to other vaccines such as those for measles, mumps or influenza, COVID-19 vaccines are designed to generate an immune ...