5 things to know about delta variant of coronavirus

Even as covid-19 vaccines become widely available and pandemic restrictions begin to relax, a new variant of the virus raises new worries.

The delta variant, first identified in India, is classified as a “variant of concern,” according to the Centers for Disease Control and Prevention.

As the variant circulates in the United States, it increased from 2.7% of all cases in May to 9.7% in June, the CDC’s director, Dr. Rochelle Walensky, said last week. In the past two weeks, it has come to represent more than 20% of coronavirus infections.

Pittsburgh-based infectious disease expert Dr. Amesh Adalja, who serves as a senior scholar at the John Hopkins Center for Health Security, addressed several questions from the Tribune-Review about the delta variant:

How infectious is the delta variant compared with other variants we’ve seen throughout the pandemic?

It appears to be the most infectious of the variants, probably 50% or more than the alpha variant.

What is the difference between a strain and a variant?

In the general public, those terms are synonymous. In a technical perspective, we refer to something as a strain when it has genetic changes that significantly alter the behavior of the pathogen.

In general, we’ve been talking about variants because there hasn’t been a major change in the behavior of the pathogen. They haven’t really crossed the threshold to call them a strain.

Are vaccinated people generally protected from the delta variant?

Yes, fully vaccinated individuals have nothing to fear from the delta variant.

However, this variant may find it very easy to spread in pockets of unvaccinated or non-immune individuals.

Why is this variant more infectious?

The delta variant has acquired a cluster of mutations that allowed it to transmit more efficiently from person to person. There are several mutations that relate to how much viral load is produced in a person and how long the period of infection is. It’s likely multifactorial.

Is the delta variant linked with more severe illness?

It’s unclear whether or not it’s linked to more severe illness.

There have been reports from the United Kingdom and China that say there may be more severe illness. But with the alpha variant, there was also that hint, which wasn’t borne out after more analysis.

You can say it’s more contagious, though it’s unclear whether it’s more severe.