Researchers have identified a new class of antibodies that are capable of neutralizing a wide range of influenza A viruses, a discovery that could potentially lead to a universal flu vaccine. The vaccine would be applied only once an, instead of once every flu season today. Protection against all strains of flue, even mutated ones, would be assured for life according to scientists at McMaster and the Icahn School of Medicine at Mount Sinai, New York.

A universal vaccine for the influenza could keep the flu at bay for life

Credit: CBC.ca

Matthew Miller, a senior author of the novel stud, and colleagues compared the potency of an isolated strain-specific flu antibody (the kind seasonal flue vaccines are based on) with an isolated broadly-neutralizing flu antibody (the stuff universal flu vaccines might be made of) in a controlled lab setting. The team found that the latter had a much weaker neutralization activity, which sounds like they’re less effective. However, when the antibodies were isolated in their natural setting from human blood, the results were comparable with the strain-specific shots. In addition, unlike the strain-specific vaccine, a vaccine based on a broadly-neutralizing antibody works against many strains of influenza.

This is the first time a detailed analysis of broadly-neutralizing antibodies in a natural setting was conducted. Antibodies derived from the lungs and upper respiratory system were found to be the most potent, according to the paper published in the Journal of Virology.

“This would prevent the occurrence of flu pandemics and poor vaccine efficiency in the case of mismatches, which actually occurred this year,” Miller said.

“This is also very encouraging and provides guidance as to what vaccine would be best for delivering a universal flu vaccine – that is, inactivated versus live-attenuated,” he added.

The inactivated vaccine is none other the flu shot you and me have to know. It consists of virus particles which are grown in eggs under controlled conditions and are then killed using a detergent-based method. This vaccine is important because it can be given to almost everyone 6 months of age and older. Each year, approximately 200,000 people in the United States are hospitalized because of influenza (the flu) and about 10,000-20,000 die. However, flu viruses are always changing. Each year’s flu vaccine is made to protect against three or four viruses that are likely to cause disease that year. As such, the flu vaccine cannot prevent all cases of flu, but it is the best defense against the disease at the moment.

The attenuated vaccine, on the other hand, is made by the reducing the potency or virulence of the pathogen, all while still keeping the virus “alive” (viable). The attenuation allows the virus to replicate harmlessly in the upper respiratory tract so that an immune response can be generated, but renders it useless at infecting the lung where disease normally occurs.

According to Miller, a universal flu vaccine could become a reality in the next five to seven years.