Delta variant

Delta Variant

The Delta variant (B.1.617.2) is a variant of the SARS-CoV-2 virus, which causes COVID-19. It was first identified in India in late 2020 and has since spread to many countries around the world. The Delta variant is known for its increased transmissibility and potential impact on vaccine effectiveness.

Virology

The Delta variant is characterized by several mutations in the spike protein of the virus, which may enhance its ability to infect human cells. Key mutations include L452R and T478K, which are thought to increase the virus's binding affinity to the ACE2 receptor on human cells.

Transmission

Studies have shown that the Delta variant is more transmissible than the original strain of SARS-CoV-2 and other variants such as the Alpha variant. This increased transmissibility is attributed to the variant's ability to replicate more efficiently in the upper respiratory tract, leading to higher viral loads in infected individuals.

Symptoms

The symptoms of infection with the Delta variant are similar to those of other COVID-19 variants, including fever, cough, and loss of taste or smell. However, some reports suggest that the Delta variant may cause more severe symptoms, particularly in unvaccinated individuals.

Vaccine Effectiveness

While vaccines remain effective against the Delta variant, there is evidence that their effectiveness is somewhat reduced compared to other variants. Studies indicate that two doses of mRNA vaccines, such as Pfizer-BioNTech and Moderna, provide strong protection against severe disease and hospitalization caused by the Delta variant.

Public Health Impact

The rapid spread of the Delta variant has led to increased cases and hospitalizations in many regions, prompting renewed public health measures such as mask mandates and social distancing. Vaccination campaigns have been intensified to curb the spread of the variant.

See Also

• COVID-19 pandemic
• Variants of SARS-CoV-2
• Vaccination against COVID-19

References

• World Health Organization: Tracking SARS-CoV-2 Variants
• Centers for Disease Control and Prevention: Delta Variant