The Delta variant, a SARS-CoV-2 mutation, is now the dominant strain in the United States, according to Yale Medicine. The variant showed up in the United States in March 2021.
The first Delta case was identified in India in December 2020, and it quickly became the dominant strain in India and the UK, according to Yale Medicine.
There has been a significant increase of the Delta variant in Indiana, Dr. Kristina Box said in an Indiana State Department of Health briefing on July 9th. The Delta variant is the most common variant the ISDH is seeing as they are sequencing new positive tests.
The Alpha variant is still the dominant strain in Indiana. It first showed up in the UK, and is about 50% more transmissible than the unmutated SARS-CoV-2 strain, according to the World Health Organization.
The Delta variant spreads 50% faster than Alpha, which spreads 50% faster than the original strain, according to Yale Medicine.
“Delta mutations are more infectious, easily transmitted and can potentially cause more severe illness,” Box said.
There is concern about the Delta variant in Indiana because many Hoosiers aren’t vaccinated. Less than 50% of people ages 40-49 are fully vaccinated, about a third of people 16-29 are fully vaccinated and less than 20% of people 12-15 are fully vaccinated, Box said.
A surge in cases because of the Delta variant is expected, especially in areas with low vaccination rates, Box said. The ISDH is not planning further social distancing restrictions at the state level, but communities can implement their own restrictions.
“We can all be vaccination ambassadors by educating ourselves,” Box said.
In Springfield, Missouri there has been a sharp increase in cases related to the Delta variant, and it is starting to overwhelm their healthcare systems, Dr. Cynthia Brown, IU School of Medicine associate professor, said.
One of the reasons the Delta variant is more infectious is that there can be up to a thousand times more viral particles in the upper respiratory tract compared to the Alpha variant, Brown said.
“People who are unvaccinated need to be very cautious in areas where Delta is circulating,” Brown said. “Almost all hospitalizations and deaths are in the unvaccinated population.”
Brown said that people who are fully vaccinated don’t need to be as concerned about the Delta variant, and in many cases, they still don’t need to socially distance or wear masks.
The best thing individuals can do to protect themselves against the Delta variant is to get the COVID-19 vaccine, Dr. Aaron Carroll, IU Director of Mitigation and Surveillance, said.
Carroll said that vaccinated people are very safe against severe illness from the Delta variant. If people are in situations with many unvaccinated people indoors, it is a good idea to socially distance and wear a mask, he said.
The Delta variant appears to be more infectious, but people who are vaccinated will hopefully mitigate the spread, Carroll said.
“The risk of severe illness and death is still massive for unvaccinated people,” Carroll said.