Common Influenza Virus Have Acquired Mutation That Escapes Antibodies, Study Finds

The novel coronavirus is known to mutate slowly. However, a team of scientists has discovered that strains of a common subtype of influenza virus have acquired a mutation that effectively blocks antibodies from attacking it.

These are the findings of a study, published online in PloS Pathogen, conducted by a team of researchers at the Johns Hopkins Bloomberg School of Public Health. The team suggests that certain subtypes of the influenza virus have almost universally acquired mutation to effectively escape the human immune system and the antibodies produced in response to the viral attack.

The scientists say that the viral mutation is able to prevent antibodies from attaching to its key viral protein. The team says that this has huge implications on the design of the flu vaccine as they may not be able to work in this case.

The current flu vaccines, which are more of a seasonal vaccine prepared against the flu strains that are dominant each season, works by regenerating immune response against a viral protein called hemagglutinin.

However, the new mutations that have been found to be dominant in the new flu reason have a mutation that alters a viral protein called neuraminidase.

During the study, the researchers found that the mutation reduced the capability of the flu virus to replicate in the human nasal cells that it normally dominates in. On the contrary, the mutation prevented the antibodies from binding to neuraminidase by creating a physical barrier.

"These findings tell us that flu vaccines focusing on the hemagglutinin protein are leaving the virus openings to evolve and evade other types of immunity," says study senior author Andrew Pekosz, lead author and professor at the Department of Molecular Microbiology and immunology at the University.

This type of mutation was first identified in the 2014 to 2015 flu season in some H3N2 flu strains. According to the team, the mutation boosted the virus’ ability to spread so rapidly that this mutation was present in virtually all circulating H3N2 strains.

The team further notes that the H3N2 flu strains have predominated the recent flu seasons, which has been more severe as compared to the other seasons before. This indicates that it is possible due to the mutation that seems to be universally acquired.