Universal Flu – Vaccine Candidate

• Disease Overview
• Prevalence and Current Treatment
• Product Candidate Description

Disease Overview

Influenza (the flu) is a highly contagious respiratory illness caused by influenza viruses. While there are only two types of influenza viruses that cause illness in humans (A and B type viruses), flu viruses, especially the A virus, can mutate and “swap” genetic material to give rise to new virus subtypes (e.g. H1N1, H3N2, H5N1, etc). These new virus subtypes can be so different from previous strains that prior immunity from vaccination or natural illness provides little to no protection against infection. According to the World Health Organization (WHO), once infected, illness can range from a mild, upper-respiratory infection to an acute, life-threatening illness. Influenza is often characterized by a sudden onset of high fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and runny nose. Influenza viruses are transmitted from person to person primarily through contact with infected airborne droplets generated by coughing and sneezing. The time from infection to illness can be as short as two days. The infectious period for influenza is defined as one day before fever begins until 24 hours after the fever ends.

Prevalence and Current Treatment

Influenza tends to spread rapidly in seasonal epidemics that occur yearly during autumn and winter in temperate regions. Illness resulting in hospitalization or death occurs mainly among high-risk groups (the very young, elderly or chronically ill). According to WHO, worldwide, these annual epidemics result in about three to five million cases of severe illness, and about 250,000 to 500,000 deaths. According to the CDC, in the United States influenza affects on average 5% to 20% of the population annually, more than 200,000 people are hospitalized from flu-related complications, and approximately 30,000 to 35,000 people die from flu or flu-related causes.

The WHO recommends vaccination as the most effective way to prevent the disease or severe outcomes from the illness. Safe and effective vaccines have been available and used for more than 60 years. Among healthy adults, influenza vaccine can prevent 70% to 90% of influenza-specific illness during seasons where there has been little change in the virus. Among the elderly, the vaccine reduces severe illnesses and complications by up to 60%, and deaths by 80%. Most healthy symptomatic people recover within a week without requiring medical attention. In some cases, an antiviral drug may be prescribed.

Product Candidate Description

A limitation of the current seasonal influenza vaccines is that they are strain specific (e.g. H3N2), and need to be adapted every year to the circulating strain. We are developing a multi-seasonal, recombinant viral vaccine that, if successful, would provide protection against multiple subtype strains. Unlike traditional flu vaccines, our approach is to use conserved antigens that do not change from year to year rather than highly variable surface proteins. We believe that presentation of these antigens using a live, attenuated viral delivery system such as Modified Vaccinia Ankara (MVA) could induce a broad protective immune response. An MVA-flu vaccine candidate may also provide a long-lived protection and, if approved, eliminate the need for annual flu shots.