SARS-CoV-2 lineage B.1.617

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Novel Coronavirus SARS-CoV-2 Spike Protein (49583626473)

SARS-CoV-2 lineage B.1.617 is a variant of SARS-CoV-2, the virus that causes COVID-19. First identified in October 2020 in India, the B.1.617 lineage has been classified by the World Health Organization (WHO) as a variant of concern due to its increased transmissibility and potential impact on vaccine efficacy. This lineage includes several sub-lineages, with B.1.617.2 (Delta variant) being the most prominent and widespread.

Characteristics

The B.1.617 lineage carries multiple mutations across its genome, with significant changes observed in the spike protein, which the virus uses to enter human cells. These mutations include L452R, T478K, and P681R, among others, which are believed to contribute to its increased transmissibility and ability to evade the immune response generated by previous infection or vaccination.

Sub-lineages

B.1.617.1

Also known as Kappa variant, it was first identified in India. While it shares some mutations with other sub-lineages of B.1.617, it has not been as widely transmitted globally as B.1.617.2.

B.1.617.2 (Delta variant)

The Delta variant has become the dominant strain in many countries due to its higher transmissibility compared to other variants of concern. It has been associated with increased hospitalization rates, though vaccines remain effective at preventing severe disease and death in most cases.

B.1.617.3

This sub-lineage has been identified in fewer sequences compared to B.1.617.1 and B.1.617.2, and as such, less is known about its characteristics and impact.

Impact

The emergence of the B.1.617 lineage has led to significant concerns regarding the global effort to control the COVID-19 pandemic. Its increased transmissibility has resulted in rapid spread in communities, leading to surges in cases and hospitalizations. Furthermore, there is evidence to suggest that this lineage may partially evade the immune response from previous infection or vaccination, although vaccines continue to provide strong protection against severe disease and death.

Response

In response to the threat posed by the B.1.617 lineage and its sub-lineages, countries and health organizations have emphasized the importance of accelerating vaccination efforts, enhancing surveillance and genomic sequencing, and implementing public health measures to control the spread. The WHO and other health authorities continue to monitor the situation closely, updating guidelines and recommendations as new evidence emerges.

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