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What you need to know about the Delta COVID-19 variant

The COVID-19 variant that ravaged India is now spreading in the United States, and some public health experts have warned that it could interfere with the progress we have made towards our return to normalcy.

The variant (B.1.617.2) is called the Delta variant as part of the World Health Organization’s quest to rename coronavirus strains to Greek letters to avoid all stigma to countries where new variants appear. The Delta variant was first detected in India in december 2020. From there it spread worldwide and has become the dominant form of the coronavirus in the UK. It is now believed to represent approximately 6.1% of cases in the United States and up to 18% in some Western and Midwestern States.

Here’s what you need to know about the Delta variant:

How is the Delta coronavirus variant different?

The Delta variant has some of the the mutations that have been identified in previous COVID-19 variants of concern. What’s unique about this one is that those mutations that were separately detected in different variants now occur together in the same strain.

These mutations could “change the way the virus attaches to a cell, facilitate an activation step and block some, but not all, of the antibodies that do the most good,” explained Benjamin neuman, chief virologist at the Texas A&M University Global Health Research Complex.

That said, it’s unclear how these mutations might actually impact the behavior of SARS-CoV-2, and just because this variant has two mutations doesn’t necessarily mean it will exhibit the behaviors of both, according to Neuman. Much more research is needed to understand what mutations do and how they impact infection.

Preliminary reports suggest that the Delta variant is more transmissible (up to 40% more than the original form of the 2019 coronavirus). There was also anecdotal reports that it causes more serious illness and bizarre symptoms like gangrene and hearing loss.

“It appears that the Delta variant has mutations associated with increased transmissibility that have also been seen in other variants, and it appears to outperform other versions of SARS-CoV-2,” said Amesh Adalja, principal investigator at the Johns Hopkins University Center for Health Security and expert in infectious diseases. But there is no conclusive evidence as to whether this causes more serious illness, Adalja added.

The researchers also initially believed that the Alpha variant – the new name for the B.1.1.7 variant first discovered in the UK could cause more serious illness. This the theory was finally debunked. It will take some time to determine if the Delta variant causes more serious illness, but Adalja doesn’t expect that to be the case.

Are people immune to COVID-19 protected against the Delta variant?

The Delta variant only seems to be a real problem among unprotected people; those who have been fully vaccinated appear to have sufficient protection against this variant. This is probably why the Delta variant has become such a problem in India, where the vaccination rate was (and is) low.

People who had already had COVID-19 also appear to be protected in the same way. Evidence has shown that although antibody levels drop after infection, another part of our immune system – the cell-mediated immune response – can take action. This part attacks the spike protein (this is what antibodies look for) and several other locations on the coronavirus. And that’s what’s going to protect those who are immune, Neuman explained.

A study from Public Health England found that two doses of the Pfizer vaccine were 88% effective against symptomatic Delta variant disease (compared to 93% effective against the Alpha variant). Two doses of AstraZeneca vaccine were 60% effective against symptomatic disease (compared to 66% against the Alpha variant). The biggest takeaway from the study, however, is that you really do need the second dose for the highest level of protection against this variant. AstraZeneca and Pfizer vaccines were 33% effective against the Delta variant in people who received only one dose.

In addition, vaccines are probably even more effective against hospitalization and death, which concerns most experts. “Where it counts, for me, it’s not a mild illness. It’s serious illness, hospitalization and death – and there all the variants are basically vaccines, ”Adalja said.

Although more research has been done on the Pfizer and AstraZeneca vaccines against the Delta variant, all vaccines attack the same part of the coronavirus, so they are likely to work the same, according to Neuman.

Will the Delta variant affect us even more as fall approaches?

It could, but not in the same way as it turned out in 2020. When the weather cools in the fall and we head indoors together, we’ll likely see more contagious variants spreading among the pockets. unvaccinated with low natural immunity.

What we probably won’t see are hospitals being pushed to their limits. “Too many high-risk people have been vaccinated,” Adalja said, so with the most vulnerable at risk of hospitalization and death protected, it’s unlikely that we will see our hospitals in crisis mode again.

The easiest and safest way to eliminate the threat of these variants (and future ones) is to shoot. “The solution to any variant is to be fully vaccinated,” Adalja said.

Experts are still learning about COVID-19. The information in this story is what was known or available at the time of publication, but directions may change as scientists find out more about the virus. Please consult the Centers for Disease Control and Prevention for the most recent recommendations.


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