5 facts on the COVID-19 Delta variant

Friday, August 13, 2021

Lab technician holding test tube for COVID-19 delta variant test.

This article has been reviewed by our chief medical consultant Dr. Charles Schutz. Source data for this article were gathered from the CDC and HHS.

COVID-19 cases are on the rise again across the United States in large part due to an extremely transmissible variant being fueled by lower vaccination rates in certain areas.

Health officials state that those who remain unvaccinated face substantial risk of severe illness and will contribute significantly to ongoing spread of the virus. In fact, almost all new cases and hospitalizations are amongst those who are unvaccinated. However, mild breakthrough cases of the Delta variant are now being reported in those fully vaccinated, which adds to the growing body of evidence that vaccines offer the best possible protection and prevent severe illness or worse.

Here are five facts to know about this strain:

  1. New Delta Cases
    As of July 31, the CDC estimates more than 90% of new infections are attributable to the Delta variant and anticipate this number will climb to 100% in the coming weeks.
  2. Highly Transmissible
    Scientists have determined that the Delta variant is approximately 60% more transmissible than the previously dominant Alpha strain, which was in turn was approximately 60% more transmissible than the original SARS-CoV-2 strain.
  3. Increased Viral Load
    According to recent studies, the number of copies of the Delta variant virus that an unvaccinated person harbors early in an infection is at least 1,000 greater than the amount harbored by those originally infected with the SARS-Cov-2 strain. Whereas the original strain carrier would infect approximately 2.5 people, a Delta carrier can likely infect up to 6 people.
  4. Hospitalization & Death Rates
    Recent hospital data across the country suggest anywhere from 97 to 99% of new hospitalizations are occurring in people who are not fully vaccinated. Public health officials are still studying the Delta variant’s effect on mortality rates. However, the CDC reported on July 16 that 99.5% of recent US deaths from COVID-19 were those unvaccinated.
  5. Vaccine Protection The vaccines appear to guard against hospitalization, severe infection, and death for those fully vaccinated. 

The bottom line is: getting vaccinated is still the only viable method of protecting ourselves, our families, and our co-workers.

For guidance about your individual health concerns related to the COVID-19 vaccines, please reach out to your primary care physicians.


Check out more resources related to COVID-19 ›