Study: Delta variant carries 1,000 times more viral load, poses greatest COVID-19 threat to date

INDIANAPOLIS (WISH) – The COVID-19 Delta variant is dominating the United States, accounting for over 51% of new infections.

Cases are also up significantly in Indiana. Currently, 74% of coronavirus infections in the state are the Delta strain. This is up from 48% last month.

Since the Delta variant — previously known as the B.1.617.2. variant — emerged in India, health experts knew it was a more contagious and infectious strain. However, they weren’t sure why.

Now, a new study sheds light as to just how big of a threat the delta mutation is. According to a recent paper under peer review, scientists found the delta strain is 225% more transmissible than the original SARs-CoV-2. In terms of severity, Dr. Amy Beth Kressel, an infectious disease specialist at Eskenazi Health, says those infected with the Delta mutation carry — on average — 1,000 times more viral load.

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“This means that every time someone who is infected breathes out, there is 1,000 times more virus [particles] in the air compared to the original strain,” Kressel told News 8. “This may affect severity. If you breathe in more virus, you may get sicker than if you breathed in less. So there is a lot of debate about what is going on with COVID. But clearly it’s more easy to spread. Additionally, people may be making others more sick at an earlier stage in the illness. It might be a day earlier than the original COVID.”

So, how did the Delta variant rise to the top? According to Kressel, it’s all about competition. Delta is winning and the Alpha, Lambda and Beta mutations are lagging behind.

“Delta is basically outcompeting everything else,” she says. “It seems to get higher levels [of infection] in people’s respiratory tracts and that may be part of the reason it spreads more easily. It may also latch on to our cells better than the original variant. As more and more people get infected different strains of the virus will emerge. Viruses like this will evolve over time and the more people who get infected the more chances it has to mutate and some of these chance mutations will just out compete the others.”

From what we know so far, Kressel says the vaccines are protective against the Delta variant. But she warns those who remain unvaccinated are playing a game of Russian roulette. Even if a person comes down with a minor case, there could be long-term effects even after the infection clears.

Eskenazi Health has partnered with various organizations to host sessions about the COVID-19 vaccine. For those interested in scheduling a town hall, please contact them via email: Public.Affairs@eskenazihealth.edu.