What is Delta Variant / COVID19 ?
Viruses are constantly changing by mutation, and new variants of a virus should appear. Sometimes new variants appear and disappear. Other times, new variations persist. Multiple variants of the virus that causes COVID-19 have been documented in the United States and around the world during this pandemic.
Viruses are constantly changing and becoming more and more diverse. Scientists are monitoring these changes, including changes in the spikes on the surface of the virus. By carefully studying viruses, scientists can learn how changes in the virus can affect the way it spreads and how sick people come out of it.
If you think of a virus as a tree that grows and branches; each branch of the tree is slightly different from the others. By comparing the branches, scientists can label them based on the differences. These small differences, or variations, have been studied and identified since the start of the pandemic.
Some variations allow the virus to spread more easily or make it resistant to treatments or vaccines. These variants need to be watched more carefully.
We are monitoring several variants; There are currently four notable variants in the United States:
- B.1.1.7 (Alpha): This variant was first detected in the United States in December 2020. It was initially detected in the United Kingdom.
- B.1.351 (Beta): This variant was first detected in the United States at the end of January 2021. It was initially detected in South Africa in December 2020.
- P.1 (Gamma): This variant was first detected in the United States in January 2021. P.1 was initially identified in travelers from Brazil, who were tested during a routine check at an airport in Japan in early January.
- B.1.617.2 (Delta): This variant was first detected in the United States in March 2021. It was initially identified in India in December 2020.
These variants appear to spread more easily and faster than other variants, which can lead to more cases of COVID-19. An increase in the number of cases will put more strain on healthcare resources, lead to more hospitalizations and potentially more deaths.
So far, studies suggest that currently licensed vaccines work on circulating variants. Scientists will continue to study these and other variants.
The main concern right now is the Delta variant, the highly contagious strain of the SARS-CoV-2 virus, which was first identified in India in December. This variant then swept quickly through the country as well as the UK and the world. The first Delta case in the United States was diagnosed in March and is now the dominant strain in the US.
Inci Yildirim, MD, PhD, a pediatric infectious disease specialist and Yale Medicine vaccine expert, isn’t surprised by what happened. “All viruses evolve over time and undergo changes as they spread and replicate,” he said.
But one thing that is unique about Delta is how fast it spreads. According to F. Perry Wilson, MD, a Yale Medicine epidemiologist, worldwide, the Delta variant is sure to accelerate the pandemic.
From what we know so far, people who are fully vaccinated against the coronavirus appear to have some protection against Delta, but anyone who isn’t vaccinated and doesn’t practice prevention strategies is at risk of being infected by the new variant, doctors say.
Here are five things you need to know about the Delta variant.
1. Delta is more contagious than other types of viruses
Delta is the name for the coronavirus variant B.1.617.2, a mutation of SARS-CoV-2 that originally appeared in India. The first Delta case was identified in December 2020, and the strain spread rapidly, soon becoming the dominant strain of the virus in India and then Great Britain.
According to Centers for Disease Control and Prevention (CDC) estimates, by the end of June, Delta had made up more than 20% of cases in the US. That number increased rapidly, prompting predictions that the strain would soon become the dominant variant here.
The World Health Organization (WHO) calls this version of the virus “the fastest and most powerful.”
In mid-June, the CDC labeled Delta a “variant of concern,” using the designation also given to the Alpha strain that first appeared in the UK, the Beta strain that first appeared in South Africa, the two Epsilon variants first diagnosed in the US. , and Gamma strains identified in Brazil.
“It’s actually quite dramatic how the growth rate will change,” said Dr. Wilson.
Delta spreads 50% faster than Alpha, which is 50% more infectious than the original strain of SARS-CoV-2, he said.
2. People who are not vaccinated are most at risk of infection People who have not been fully vaccinated against Covid-19 are most at risk.
In the US, a number of Southern and Appalachian states, including Alabama, Arkansas, Georgia, Mississippi, Missouri, and West Virginia, have low vaccination rates. In some of these states, the number of cases continues to rise even as other states lift restrictions as their cases decline.
Children and youth are also a concern. “A recent study from the UK showed that children and adults under 50 years of age are 2.5 times more likely to be infected with Delta,” said Dr. Yildirim.
3. Deltas can cause ‘hyperlocal outbreaks’
If Delta continues to move fast enough to accelerate the pandemic, Dr. Wilson said the biggest question was about contagion—how many people would get the Delta variant and how fast would it spread?
The answer depends on how many people in a given area are vaccinated. “I call it a ‘vaccination patchwork’, where you have a highly vaccinated pouch adjacent to a site that has 20 percent of vaccinations,” says Dr. Wilson.