A peer–reviewed study published in Science magazine has revealed that that two older variants of Covid-19—Alpha and Beta — are circulating in India with changes to their structures.
Alpha variant was first found in the UK, while beta variant was first found in South Africa.
The study has warned that current vaccines may be less effective against the Beta variant—though a booster may work. The study has come as a fresh warning that existing covid vaccines may not be effective against new variants, that have been evolving at an alarming pace.
The latest in a series of structural studies of the variants’ spike protein led by Bing Chen at Boston Children’s Hospital, US, revealed new properties of the Alpha and Beta mutants. Chen’s team is also planning to report the structures of other variants of concern, including the Delta variant (B.1.617.2), in the near future.
Spike proteins are found on the surface of the virus. They enable the virus to attach to and enter human cells. All current vaccines target spike protein. The latest study used cryo-electron microscopy to compare the spike protein of the original virus with those of Alpha and Beta.
The findings indicate that mutations in the Beta variant change the shape of the spike surface at certain locations in the body.
As a result, neutralizing antibodies induced by current vaccines are less able to bind to the Beta virus, which may allow it to evade the immune system even when people are vaccinated.
“The mutations make antibodies stimulated by the current vaccine less effective. The Beta variant is somewhat resistant to the current vaccines, and we think a booster with the new genetic sequence can be beneficial for protecting against this variant,” Chen said.