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What We Know About the COVID-19 Delta Strain

By September 10, 2021October 23rd, 2023Expert Advice Featured Well-being
Shot of two scientists working together on a computer in a lab

We’ve come a long way since March 2020 when the COVID-19 virus caused millions of people across the globe to stay home in an effort to flatten the curve.

As of now, more than 50 percent of the U.S. population is fully vaccinated. While this is a great start, we’re not out of the woods yet.

One major concern right now is the rise of the latest COVID-19 variant, the highly contagious Delta strain that is now the predominant variant in the United States. The COVID-19 Delta strain makes up roughly 83 percent of recent U.S. cases. And its highly contagious nature means that it spreads two to three times faster than the original strain of the virus.

The current vaccines are effective against the contagious Delta strain of the virus, but to reduce the overwhelming impact on hospitals and health systems and protect the vulnerable, we still need to get more people vaccinated. So, if you haven’t been vaccinated yet, now’s the time to do it to help protect yourself and the community.

A Look at the Delta Variant

Variants are a normal result of a virus spreading from person to person over time. Viruses evolve and mutate constantly, especially coronaviruses and influenza viruses. That’s why doctors recommend a new flu vaccine every year.

Each time a virus mutates, a new variant is created. The variant that spreads the easiest is what becomes the most prevalent. In this case, it’s the Delta variant. This strain’s ability to spread is what is most concerning. To illustrate how contagious Delta is, Yale Medicine epidemiologist Dr. F. Perry Wilson uses the hypothetical example of a situation without any COVID-19 precautions in place (no masks, no vaccinations).

The average person with the original COVID-19 strain would infect 2.5 other people. If that same person had the COVID-19 Delta strain, they would infect, on average 3.5 to 4 other people.

Vaccinations are Critical

We are fortunate that the vaccines are highly effective against the contagious Delta strain of the virus and are keeping people out of the hospital. But it’s a race against the clock to get more people vaccinated before another, potentially more deadly strain arises. The more the virus spreads, the more likely it is to mutate and become vaccine-resistant. We can’t allow this to happen.

Vaccine Effectiveness

There are currently three COVID-19 vaccines that have been authorized by the FDA for emergency use in the United States: Pfizer, Moderna, and Johnson and Johnson. This is how each stacks up against the Delta variant:

Pfizer (after two doses)
95% effective against original COVID-19 strain
88% effective against Delta strain

Moderna (after two doses)
94% effective against original COVID-19 strain
88% effective against Delta strain

Johnson & Johnson
72% effective against original COVID-19 strain
Studies are still being reviewed to see how effective the Johnson & Johnson vaccine is against the Delta strain

The Importance of the Second Dose

If you get the Pfizer or Moderna vaccine, it’s very important to get both doses of the vaccine in order to get maximum protection since studies show a significant decline in vaccine effectiveness if you only get the first dose.

A Closer Look at Hospitalizations

A look at the current COVID-19 hospitalization statistics illustrates just how effective the vaccines are:

Protecting Our Children

For parents of children under the age of 12, who cannot be vaccinated yet, the Delta variant can be scary. But there are steps you can take to continue protecting your children until a vaccine becomes available for them.

  • Get vaccinated. Protecting the people who are closest to your children is the best way to protect them right now.
  • Get your teen vaccinated. If you have a child 12 or older, it’s important to get them vaccinated. Every vaccinated person in your family is another layer of protection for children too young to be vaccinated.
  • Continue mask-wearing. Have your children (ages 2 and older) continue to wear a mask in public settings, especially if indoors. If you are vaccinated, it’s recommended that you continue wearing a mask in certain settings. Since there are instances of vaccinated people getting a breakthrough infection with the Delta variant (which they can then transmit), you should continue to wear a mask in public, especially if you have unvaccinated children or high-risk family members at home.
  • Limit time spent with unvaccinated people. If your child is under 2 years old, limit visits with people who are not vaccinated (or whose vaccination status is unknown) and practice social distancing in public settings.

Parents of younger children can expect that their little ones should be eligible for the COVID-19 vaccine in the coming months. Dr. Anthony Fauci said that he expects the COVID-19 vaccine to become available to children ages 2 through 11 by late 2021 to early 2022.

Vaccinations Are Your Best Bet

Protect yourself and your loved ones from the Delta strain by getting vaccinated. We need to work together to stop the spread of the Delta strain. If you still have questions about vaccinations, check out the below trusted and unbiased sources:

The bottom line is vaccinating as many people as possible as quickly as possible is the best chance we’ve got to end this pandemic once and for all.

Dr. Dolores Roman

Dr. Dolores Roman joined Independence Blue Cross in 2019. As a 20-year veteran of emergency rooms in and around the Philadelphia area, Dr. Roman has dealt with every kind of emergency. Now as a medical director at Independence, Dr. Roman is involved in utilization management, case management, and quality improvement. What Dr. Roman loves most about this job is the opportunity to collaborate with colleagues in order to enhance the health and well-being of those served by Independence Blue Cross.