Delta+ Calls For Caution, Not Panic

Virus will mutate. That’s its nature. But its spike protein & antigens are being pounded by vaccines

-  K Srinath Reddy

Designation of the newly emerged Delta-plus as a “variant of concern” has triggered a debate on implications for viral transmission and vaccine efficacy. This variant is also called AY.1. The notoriety that its Delta precursor acquired, through rampant global spread, has raised alarm as to whether this debutante might derail progress in our pandemic response. Present indications are that there is no cause for panic.

As of now, the Delta-plus variant has been found in a relatively small number of individuals in India and a few other countries. The Delta variant continues to be the immediate threat globally. It is uncertain as to whether, where and when it will make way for the new variant. The ‘plus factor’ in AY.1 comes from an additional mutation it has picked up over the Delta.

The K.417.N mutation is also present in the Beta variant first described in South Africa. Since the Beta variant has higher infectivity and lower levels of vaccine efficacy than the original wild virus or the Alpha variant, concerns about the Delta-plus variant are understandable. However, we need more data on both infectivity and possible vaccine evasion. From the small number of cases reported so far globally, there is no evidence of increased virulence.

Emergence of variants is a common occurrence among respiratory viruses. Evolutionary biology steers their quest for survival as a species. The vast human population is an attractive host the virus is loath to abandon. To continually spread, the Covid-19 virus must constantly find new humans to infect and in whose cells it can replicate. When it meets obstacles to transmission, it mutates to overcome them.