Why the Delta Variant is So Concerning: What You Need to Know

Answers to key questions about this even more contagious coronavirus

Robert Roy Britt
Published in
5 min readJul 30, 2021


Image: Pixabay

Here we go again. The Delta variant of the coronavirus is more contagious than anything we’ve seen during the pandemic so far. It’s so contagious, it’s squeezing out its SARS-CoV-2 brethren to become the predominant variant in circulation.

So what should you do?

Whether you are vaccinated or not, it’s time to mask up and take other preventive steps if you wish to ensure the safety of yourself and your loved ones and the people in your community, experts say.

Given the situation is evolving quickly, here are answers to the key questions you might have:

What is the Delta variant and where is it?

From very early days, the original pandemic-producing coronavirus, called SARS-CoV-2, has been mutating in mostly insignificant ways. Over time, left to hop from one human host to another, those mutations have added up to several variant strains of the original with some significant new features, including greater transmissibility. The Delta strain has emerged as the most infectious.

And it’s everywhere. More than 80% of new Covid cases in the United States were caused by the Delta variant as of July 17, compared to just 30% on June 19 — a huge increase in a short time.

How infectious is the Delta variant?

Very. The CDC now says this strain of the coronavirus is more infectious than the common cold, the flu, Ebola, smallpox and chickenpox, according to internal CDC documents obtained by the New York Times.

Do the vaccines work against the Delta variant?

Yes, but perhaps ever-so-slightly less so, according to a study published July 21 in the New England Journal of Medicine. Vaccines were never said to be 100% effective, and so far it appears they’re holding up very well against all known variants. “Covid vaccines are not perfect. But they are darn good, and keep you alive. Even with delta, alpha, gamma, kappa, lambda, etc.,” tweets Mayo Clinic researcher Vincent Rajkumar, MD. [See



Robert Roy Britt

Editor of Aha! and Wise & Well on Medium + the Writer's Guide at writersguide.substack.com. Author of Make Sleep Your Superpower: amazon.com/dp/B0BJBYFQCB