As of May 5, the U.K. reported 261 confirmed B.1.617 cases, the largest number of COVID-19 cases caused by the variant outside India.
On May 10, 2021, The World Health Organization declared the B.1.617 strain, first discovered in India, a variant of concern. The International body said that after India, the United Kingdom reported the highest COVID-19 cases sequenced as B.1.617.
The WHO SARS-CoV-2 Virus Evolution Working Group has recognized three sub-lineages to the B.1.617 variant, including B.1.617.1, B.1.617.2 and B.1.617.3. Of the three sub-lineages, the U.K. has declared the B.1.617.2 as a variant of concern as it has reported 520 confirmed B.1.617.2 cases. Additionally, as of May 5, 2021, the U.K. noted 261 confirmed B.1.617 case and nine confirmed B.1.617.3 cases.
In October 2020, experts performing genomic sequencing determined the B.1.617 SARS-CoV-2 variant after analyzing the Maharashtra COVID-19 case samples.
According to WHO, the B.1.617 variant has a potential increase in transmissibility. It also reported that the same variant has a higher growth rate than other variants in the country. The recent surge of COVID-19 cases in India can be attributed to both the infectious variant and the increase in social and religious mixing in the country.
A preliminary laboratory study that is yet to be peer-reviewed suggests that the B.1.617 lineage on vaccine effectiveness has a minimal reduction in antibody neutralization. However, WHO has noted that "real-world" impacts may vary.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.