Experiments performed on mice showed that the vaccine elicited a strong antibody response to a structure on the surface of flu viruses, called the hemagglutinin (HA) and protected them from infection by various flu strains.
Unlike the seasonal flu vaccines that are updated every year, the new vaccine can also be given a few times over a lifetime to provide protection potentially similar to a tetanus vaccine.
"This vaccine was able to do something that most other candidate flu vaccines have not been able to do," said study co-senior author Drew Weissman, Professor at the University of Pennsylvania in the US.
"If it works in humans even half as well as it does in mice, then the sky's the limit -- it could be something that everyone uses in the future to protect themselves from the flu," added Scott Hensley, Associate Professor at the varsity.
The findings are described in the journal Nature Communications.
As opposed to the seasonal flu vaccines, the new vaccine does not directly use flu HA proteins, instead, it uses mRNA molecules that encode HA proteins to elicit an antibody response.
When injected into a recipient, these RNAs are taken up by immune system dendritic cells and translated into copies of the HA protein by the protein-making machinery within those cells.
This within-cell production of viral proteins does a better job of mimicking a real flu infection and elicits a very powerful protective antibody response, the researchers explained.
The team observed that after immunisation, these strong antibody responses to the vaccine persisted through thirty weeks of the experiment.
In addition to the mice, the researchers successfully repeated these experiments in ferrets and rabbits, other species commonly used as vaccine-development animal models.
"Because there are no treatments for Alzheimer's disease, it is crucial that we find ways to prevent it and delay its onset," said study researcher Albert Amran from the University of Texas Health Science Centre in the US.
"About 5.8 million people in the US have this disease, so even a small reduction in risk can make a dramatic difference. We began our study by looking for ways we could reduce this risk," Amran added.
The aim of the researchers was to pinpoint potential factors that could reduce Alzheimer's disease risk.The role was to sort through enormous amounts of de-identified patient data in the Cerner Health Facts database to see whether there are drugs that could be repurposed to reduce the risk of Alzheimer's disease.
Once the team identified the flu vaccine as a candidate, they used machine learning to analyse more than 310,000 health records to study the relationship between flu vaccination and Alzheimer's disease. The study found that more frequent flu vaccination and receiving a vaccination at younger ages were associated with even greater decreases in risk.
"One of our theories of how the flu vaccine may work is that some of the proteins in the flu virus may train the body's immune response to better protect against Alzheimer's disease," Amran said.
"Providing people with a flu vaccine may be a safe way to introduce those proteins that could help prepare the body to fight off the disease," he added.
The researchers noted that additional studies in large clinical trials are needed to explore whether the flu shot could serve as a valid public health strategy in the fight against this disease.
"More research is needed to investigate why and how the flu vaccine works in the body to help prevent Alzheimer's disease," the authors wrote.
The study was presented at the 2020 Alzheimer's Association International Conference on July 27-31. The conference was held virtually due to Covid-19.
More Stories:
Brain Protein That Could Protect Against Alzheimer’s Disease
Drug For Alzheimer’s Disease Increases Hospitalisation Risk
For the findings, the research team analysed more than 13,000 patients tested for Covid-19 at Cleveland Clinic in the US, between early March and mid-April of this year. "Our findings suggest that we should proceed as usual with our vaccination strategy for global influenza this flu season," said study author Joe Zein from Cleveland Clinic in the US.
"Getting the annual flu vaccine remains the best safeguard against the influenza virus--both for yourself and the people around you," Zein added.
Comparing those who had received unadjuvanted influenza vaccines in the fall or winter of 2019 (4,138 patients) against those who did not receive the vaccine (9,082 patients) revealed that influenza vaccination was not associated with increased Covid-19 incidence or disease severity, including risk for hospitalization, admission to the intensive care unit or mortality.
Since much is still unknown about the possible outcomes of concurrent Covid-19 and influenza infection, researchers and clinicians believe that the population's adherence to widespread and early flu vaccination will help to mitigate the risk of simultaneous viral infections and epidemics/pandemics.
"We have already seen the stress that Covid-19 can put on our hospitals and resources," Zein said.
"While we're not yet sure how flu season will affect Covid-19 susceptibility and infections, we strongly advise people to get their influenza vaccines, both for their individual health and the collective health of our care systems," Zein added.
According to the researchers, seasonal flu activity is unpredictable, and otherwise healthy people are hospitalized due to serious respiratory infection each year.
"This year, it's even more important to receive the flu vaccination to help prevent a twindemic of flu and Covid-19," the study authors wrote.
(IANS)
Read More:
COVID-19: Scientists Predict That Coronavirus Will Become Seasonal Virus
COVID-19: Coronavirus Was Made In Chinese Lab, Claims Whistleblower Virologist Li