New Approach to Universal Flu Vaccine at Icahn School of Medicine

Significance of Influenza Vaccination

A team of researchers at the Icahn School of Medicine at Mount Sinai has conducted a groundbreaking study that advances the development of a universal flu vaccine. Influenza is responsible for considerable illness and mortality across the globe. This viral infection is caused by the Influenza virus, which undergoes a process known as antigenic drift, altering its strain over time. Consequently, seasonal influenza vaccines are formulated based on predictions for each flu season, often resulting in mismatches that reduce their effectiveness. Additionally, current vaccines are ineffective during pandemics, as it typically takes months to produce a vaccine that aligns with newly emerging strains. This underscores the urgent need for a universal flu vaccine capable of providing protection against all influenza virus strains.

Focus on Hemagglutinin Protein

Hemagglutinin is a key protein found on the surface of the influenza virus that facilitates the virus’s binding to infected cells. This protein comprises a head and a stalk; while the head varies significantly among different strains, the stalk remains more consistent. Researchers aimed to evaluate vaccines designed to target the stalk of this protein, specifically the chimeric hemagglutinin-based vaccines (cHA-based vaccines).

Study Design and Methodology

The study enrolled 65 participants over a one-month period from October to November 2017 across two hospitals in the United States. Multiple cHA-based vaccination regimens were tested to determine their efficacy in generating immunity against a range of influenza viruses. The study results were published in The Lancet Infectious Diseases. The tested regimens included both live attenuated and inactivated vaccines, alongside the use of an adjuvant—a substance that enhances vaccine effectiveness. Participants received an initial vaccine dose, followed by a booster dose in some regimens. Researchers assessed the immunity developed by participants through various parameters measured in blood samples taken at specific intervals after vaccination.

Key Findings

The study revealed that a substantial immune response was achieved following a single dose of the inactivated cHA-based vaccine. All tested regimens demonstrated strong immunity after the booster dose, providing broad protection against various influenza virus types, including both bat and bird influenza. Notably, all regimens were well-tolerated and did not raise any safety concerns.

Researcher Insights

“It was surprising to find that the inactivated formulation with adjuvant induced a very strong anti-stalk response already after the prime suggesting that one vaccination might be enough to induce protection against pandemic influenza viruses yet to arise,” stated Florian Krammer, Ph.D., Professor of Microbiology at the Icahn School of Medicine. He emphasized that while these results indicate progress toward a universal influenza virus vaccine, they remain interim findings, with additional results expected upon the study’s completion at the end of 2019.

References

– THE LANCET Infectious Diseases: Immunogenicity of chimeric hemagglutinin-based, universal influenza virus vaccine candidates: interim results of a randomized, placebo-controlled, phase 1 trial.
– EurekAlert! (17 Oct 2019) Mount Sinai researchers bring us one step closer to universal influenza vaccine. https://www.eurekalert.org/pub_releases/2019-10/tmsh-msr101619.php

Image Credit

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