Four biologists from Illinois State University’s School of Biological Sciences offered insights to a few frequently asked questions on the Delta variant, breakthrough infections, virus transmission, and vaccine timing.   

headshot of Laura Vogel
Dr. Laura Vogel
headshot of Dr. Jan-Ulrik Dahl
Dr. Jan-Ulrik Dahl

“Thousands of scientists and healthcare professionals around the world are studying both SARS-CoV-2 [the coronavirus] and the vaccines,” said Professor of Immunology Laura A. Vogel. “With the spread of the highly contagious Delta variant, we see the global focus is back on prevention.” Vogel’s research centers on the immune system and how white blood cells protect against infection.

Joining Vogel in answering questions are three fellow biological sciences professors who study and lead labs in infectious disease and microbiology. Associate Professor Ben M. Sadd oversees the Infectious Disease Ecology Lab at Illinois State. Associate Professor of Microbiology Wade Nichols studies the genetics of microbial pathogenesis. Assistant Professor of Microbiology Jan-Ulrik Dahl’s research explores how bacteria respond to changes in their environment on organismal and molecular levels.   

headshot of Dr. Wade Nichols
Dr. Wade Nichols
Man with a backpack standing in front of mist-covered foliage
Dr. Ben Sadd

Dahl noted the amount of information being analyzed on a global scale can help to keep responses timely. “New data is constantly being gathered, evaluated, and discussed, which is all part of the normal scientific process,” said Dahl. “New data informs changes in global, national, state, and local responses. These changes can happen quickly as health providers work to keep communities safe.”   

Students, faculty and staff with questions about vaccine safety and effectiveness are encouraged to ask questions of their health care provider, Student Health Services, and local pharmacists who are providing the vaccine. Illinois State University continues to gather information and adjust COVID-19 prevention and mitigation strategies based on the newest data and as recommended by the Illinois Board of Higher Education (IBHE), Illinois Department of Public Health (IDPH), and the Centers for Disease Control and Prevention (CDC). 

What is known about the Delta variant?

  • As of August 10, 2021, the Delta variant is the predominant SARS-CoV-2 strain found in hospitalized patients in the US.
  • Early data suggest that Delta infections potentially result in a 1000-fold higher virus number and a transmissibility twice as high as the original variant.
  • Because of its transmissibility, Delta presents a major threat for unvaccinated people.
  • The Delta variant is highly contagious, and scientists are still investigating whether the Delta variant makes infected people sicker than earlier variants.
  • However, the current vaccines are very effective against the Delta variant and  protect against severe disease.
  • Researchers predict the variant will continue to spread and new variants are emerging, so preventing infections is key to controlling the pandemic.

But I’ve heard vaccinated people are getting “breakthrough infections”

  • Given that (i) no vaccine is 100 percent effective and (ii) more people are vaccinated, it is not unexpected that breakthrough infections in vaccinated people occur. However, it is important to note that the severity of the infection is significantly lower in vaccinated people.
  • Breakthrough infections have been reported in less than 1% of vaccinated people and the majority of them exhibit no or minimal symptoms.
  • As of August 2, 2021, there were 7,525 hospitalized or fatal vaccine breakthrough cases reported to the CDC. Given that over 164 million people in the US have already been vaccinated, serious breakthrough cases are very rare (about 0.004%)
  • Scientists are still investigating whether the virus is also more infectious in breakthrough cases. Early data suggest that vaccinated people with breakthrough Delta variant infections have the potential to transmit more than with other variants.
  • Given the higher virus load and increased transmissibility of Delta, masks provide an  additional layer of protection from virus transmission and have therefore been recommended by the CDC for indoor settings.
  • Researchers are continuing to monitor these breakthrough cases and identify patterns or trends in:
    • Patients’ characteristics, such as age or underlying medical conditions;
    • The specific vaccine that patients received; and
    • Whether a specific SARS-CoV-2 variant caused the infections.

I’m concerned that if I attend in-person classes I will get infected and unknowingly give the virus to my children or at-risk family members.

  • Being fully vaccinated is the most important factor for reducing your risk of becoming infected with SARS-CoV-2.
  • Properly wearing a mask in indoor settings will further decrease the risk of the virus spreading among students and faculty.
  • Handwashing, distancing, and isolating if you are sick further decrease the risk.

How can I best protect myself against the Delta variant?

  • The best protection is a full vaccination with one of the approved vaccines.
  • Masks provide additional protection and help reduce the spread of COVID-19 in classrooms.
  • Keep physical distance in outdoor settings when without a mask.

I’m not vaccinated yet, is it too late?

  • It’s not too late to get vaccinated! Getting vaccinated is still the most effective way to protect yourself, your children and elderly family members, and your community.
  • Researchers continue to work towards getting full FDA approval for vaccines and emergency use authorizations for younger children. They continue to carefully evaluate new data to make sure the vaccines are safe and effective for all ages.