The Delta variant (B.1.617.2)

What is the Delta variant?

The Delta variant (B.1.617.2) of severe acute respiratory syndrome?coronavirus 2 (Sars-CoV-2), which was first detected in India in October 2020, has been identified in at least 92 countries and is regarded the "fittest" form of the virus that causes coronavirus disease 2019 (COVID-19) yet1,2.

The virus's spike protein exhibits a number of major mutations in the Delta version. These spikes have been found to bind to angiotensin-converting enzyme 2?(ACE-2) receptors in studies. The infection spreads by reproducing the virus's genetic code once these spike proteins have unlocked the cells. The E484Q, L452R, and P614R alterations in the Delta version make it simpler for the virus's spikes to bind to ACE-2 receptors. This means it can infect and multiply more quickly, as well as efficiently avoid the body's natural disease-fighting immunity 2.

?Transmissibility of the Delta variant:

According to research done in the United Kingdom, where the variation accounts for 99% of new COVID-19 cases, it is 60% more transmissible than the previously dominant Alpha version. It's also related to a higher risk of hospitalization and is more vaccination resistant, especially after only o

Symptoms of the Delta variant:

According to researchers, the most common symptoms of the Delta variant are headaches, sore throat, and a runny nose. On the other hand, according to the National Health Service (NHS), characteristic COVID-19 symptoms include fever, cough, and loss of smell or taste 3.

Situation of the Delta variant in Bangladesh:

According to the Institute of Epidemiology, Disease Control and Research (IEDCR), the Indian-origin Delta variation of Sars-CoV-2 is now the most active form in Bangladesh. The IEDCR informed in a report on Sunday that the Delta variant established its dominance in June, appearing in 78% of all samples sequenced during the month. On May 8, Bangladeshi health officials first discovered the Delta variant of Sars-CoV-2. The IEDCR, together with icddr,b and iDeshi, sequenced 646 genomes between January and June, according to the latest report 4.

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Vaccines effectiveness against the Delta variant:

A Public Health England study demonstrates that two doses of the COVID-19 vaccination are highly effective against the Delta variant. The study looked at data from all age groups starting on April 5 and covering the time when the B.1.617.2 variation was discovered. It comprised 1,054 people who had the B.1.617.2 variation verified by genome sequencing, as well as people of various nationalities. The vaccination efficacy data released on Thursday, May 20th, covers the period since December for individuals aged 65 and up. Findings of that study are given below:

·??????Two weeks following the second dosage, the Pfizer-BioNTech vaccine was 88% effective against symptomatic illness caused by the Delta variant, compared to 93% for the Alpha variant.

·??????Two doses of the AstraZeneca vaccine were 60% effective against symptomatic illness caused by the Delta variant, compared to 66% for the Alpha variant.

·??????Three weeks after the first dose, both vaccines were 33% effective against symptomatic illness caused by the Delta variant, compared to 50% for the Alpha variant 5.

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???References:

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1.????Grover, N. (2021, June 27). Delta Covid variant may be edging race against vaccines.?The Guardian. https://www.theguardian.com/world/2021/jun/27/delta-covid-variant-may-be-edging-race-against-vaccines

2.????Kapur, M. (2021, June 29). How dangerous are Covid-19 Delta and Delta Plus variants??Quartz. https://qz.com/india/2024190/how-dangerous-are-covid-19-delta-and-delta-plus-variants/

3.????FIT. (2021, June 15). Delta Variant of COVID Causes Cold-Like Symptoms in the UK: Study.?TheQuint. https://www.thequint.com/amp/story/coronavirus/corona-virus-variant-delta-causes-cold-like-symptoms-says-a-uk-study

4.????Hasan, M. (2021, July 4). IEDCR: 78% Covid cases in June caused by Delta variant.?DhakaTribune.https://www.dhakatribune.com/health/coronavirus/2021/07/04/iedcr-delta-variant-dominant-in-bangladesh

5.????Public Health England. (2021, May 22). Vaccines highly effective against B.1.617.2 variant after 2 doses.?GOV.UK. https://www.gov.uk/government/news/vaccines-highly-effective-against-b-1-617-2-variant-after-2-doses

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