Why is Delta variant more transmissible?
The Delta Variant, which is said to have led the second wave of coronavirus in India, has been a matter of concern for many scientists and experts. The World Health Organization (WHO) recently categorised the deadly variant as a 'variant of concern', stating the serious dangers it can pose to people's health and physical well-being. However, the question still remains as to what makes the Delta variant so concerning and dangerous? If it is more transmissible, why is it so?
What is the Delta Variant?
The Delta variant, scientifically termed as B.1.617.2 of coronavirus, is a combination of two mutations that make it more transmissible and infectious than other variants that exist.
The first case of the Delta variant was detected in India in December 2020. The virus strain is known to spread faster than any other variant in the world and has become one of the most dominant strains in the United Kingdom. Currently more than 80% of new U.S. COVID-19 cases are caused by the Delta variant, as per the Centre for Disease Control and Prevention (CDC).
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Why is it a 'variant of concern'?
The Delta variant, which is now a 'variant of concern', is said to be spread faster and more efficiently from person to person.
Considering that the delta variant carries the genetic code from two other mutations, E484Q and L452R, it becomes all the more easy for it to break into the human immune system and invade the organs. In addition to that, as the new variants tend to alter the structure of the spike protein, it is more efficient in attaching itself to the human host cells and multiplies swiftly, doing more damage than an originally COVID strain.
Apart from that, experts believe that the B.1.617.2 lineage of coronavirus can also dodge antibodies provided by vaccines as well as past COVID infections. Breakthrough infections have been reported in the past and continue to pose a major challenge to vaccine efficacy.
What makes COVID Delta variant more transmissible?
After contributing to the second wave of COVID-19 in India, the Delta variant has continued to wreak havoc all around the world.
While its ability to escape natural as well as vaccine-induced immunity is a matter of grave concern, scientists are looking into the elements that make it more transmissible, which is actually what makes it more dangerous and concerning.
In a study conducted at China's Guangdong Provincial Center of Disease Control and Prevention, a team of researchers tracked and quarantined 62 people following their exposure to COVID-19. After analysing the infected individuals and studying their viral load, it was found that the patients infected with the Delta variant had 1,260 times higher viral load than those who contracted the original COVID strain.
Additionally, the study stated that people infected with the Delta variant showed signs of the virus four days after contact, whereas it took an average of 7 days to detect the same in people infected with the original strain.
Higher viral load means increased transmissibility
A viral load is the amount of viral particles in an infected person's blood. It determines the severity of the disease and how infectious the virus can be.
According to the study, the high viral load in people infected with the Delta variant is what is leading to the faster spread of the virus from one person to another. The study indicates that the Delta variant replicates and multiplies at a faster rate than the original strain.
This can also make a person more prone to severe infection, leading to more serious symptoms and complications.
Scientists believe that the high viral load in infected people is what is causing the surge in the number of the COVID cases, globally.
Can vaccines prove effective against the Delta variant?
Since the Delta variant is a combination of two mutations, it's ability to escape antibodies is said to be more efficient. Scientists have raised concerns that the newer variants, especially the Delta variant, contain properties that help them escape immune defences and assists them in dodging vaccine driven protection, leading to breakthrough infections.
However, while fully vaccinated people can contract the virus, they are less likely to contract severe illnesses and may be less prone to hospitalisation risks. The Centre for Disease Control and prevention has also claimed that people who have received both their COVID doses are less likely to spread the virus too.