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Is the Vaccine Effective Against the Delta Variant?

Delta Variant and Vaccines

Author: Dr. Rohini R

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The delta variant, also called the B. 1. 617 is a mutant strain of the coronavirus (COVID-19) which was first detected in 2019 and resulted in the global pandemic. The delta variant, was first detected in India last year, which has since spread to dozens of other countries, and is now the dominant strain in many countries . The Delta variant has several lineages with different sets of mutations, one of them being the B. 1.617.2 strain which is also now the dominant coronavirus variant in the United Kingdom. Studies have shown the delta variant is 50 percent more contagious than the original COVID-19 virus, with a higher risk of complications and hospitalisation, making the delta variant a serious concern. However, the vaccines are effective against the delta variant. The vaccine significantly decreases the risk of severe disease, hospitalisation and death.

Those infected by the  the delta variant have presented with symptoms that slightly vary from those seen by people who contracted the original virus, however there is very little research data available on this. The most common initial symptoms of the delta variant have found to be fever, sore throat, runny nose and headache, without the presence of the characteristic signs of the original COVID-19 virus, such as loss of smell and taste. Hence it is important to recognise the symptoms and get tested early.

Are the Vaccines Effective Against the Delta Variant?

Pfizer vaccine: 

The Pfizer-BioNTech vaccine was found to be 36 percent effective against symptomatic disease caused by the delta variant after the first dose and 88 percent effective after the second dose. In terms of hospitalisation, the Pfizer vaccine was found to be 94 percent effective in preventing hospitalisation  after the first dose and 96 percent effective after the second dose.  

Mederna vaccine:

Moderna vaccine uses the same technology as Pfizer, hence researchers believe it would provide similar protection as Pfizer. 

AstraZeneca vaccine:

The AstraZeneca vaccine was found to be 60 percent effective against symptomatic disease caused by the delta variant and 92 percent effective against complications and hospitalization after both doses. This vaccine is available in India as Covishield.

Johnson & Johnson vaccine:

This is a single shot vaccine. A study based on laboratory tests showed that the vaccine had a diminished immune response to the delta variant. However some studies suggest that it can provide effective protection against the delta variant for months after vaccination. Some researchers believe the Johnson & Johnson vaccine would provide similar results to the AstraZeneca vaccine. 

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