Where did the covid-19 delta variant come from?
The Delta covid-19 variant, which first appeared in India in February, is now present in a dozen countries worrying health officials worldwide.

The technical designation of the rapidly spreading coronavirus variant, the B.1.617.2 strain, was simplified to Delta along with the other "variants of concern". The Alpha variant, first discovered in the UK, is presently the dominant variant in the US but the Delta variant is quickly increasing in the proportion of new infections in the US.
Just a month ago the Delta variant accounted for just one percent of new sequenced covid-19 cases in the United States has now jumped to six percent. There are worries that it could overwhelm healthcare systems as it travels through the unvaccinated portions of the population.
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What is known about the Delta variant
The strain first appeared in late 2020 and is believed to be behind the rampant spread of the virus in India over the past two months. The strain has mutations that make it more easily transmissible aiding it to become the dominant variant in the UK with it comprising 91 percent of new cases according to the Health Secretary.
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— Harry Cole (@MrHarryCole) June 11, 2021
There have been a series of outbreaks across the UK since it was detected in the country leading the government to send military personnel to the hotspots. The government is also reconsidering easing covid-19 restriction which were set to end 21 June.
There are fears that it could also evade the immune response in those that are vaccinated. Recent research found that of the five variants tested in the study, the Pfizer vaccine was least effective against the Delta variant. However, being vaccinated should provide protection from getting seriously ill and prevent hospitalization.
How do variants develop?
“We know that viruses mutate to live and live to mutate,” Dr. Brannon Traxler, DHEC Interim Public Health Director in South Carolina said when the Beta variant from South Africa was first discovered in the United States. The more hosts a virus infects, the more opportunities it has to spread and create new versions of itself. The longer it can remain in a host also gives it the opportunity to make more changes.
Great news for mRNA vaccine protection against the delta (B.1.617.2) variant, just out @Nature 👍👍https://t.co/bSnR3cJyYP
— Eric Topol (@EricTopol) June 10, 2021
potent neutralizing antibody response generated @BioNTech_Group/@pfizer which goes along with some clinical effectiveness data pic.twitter.com/X8XeD9peoX
The current covid-19 vaccines that are available should be able to provide protection against this variant and others. But to stay ahead of the game researchers are already working on possible boosters to strengthen the immune response in those who are fully vaccinated.