By Sophie Boulter and Morgan Miles, World News editor and staff writer

The delta variant, a highly contagious variant of COVID-19, became the dominant strain in the United States on July 7. Experts warn that this variant may be more dangerous than the more commonly-known alpha variant.

The delta variant is now spreading 50% faster than the alpha variant, which spread approximately 50% faster than the original strain of COVID-19. Dr. Aziz Sheikh, a professor at the University of Edinburgh, emphasized that “The thing we were surprised by is just how rapidly the delta variant took hold.”

The new strain was first discovered in India in December 2020. As of July 21, the variant has spread to 124 countries and is on track to be the dominant strain of COVID-19 worldwide, according to the World Health Organization. 

In the U.S., all FDA-approved vaccinations have proven to be at least somewhat effective in protecting against the delta variant. Though the vaccines are not as effective against the COVID-19 variants as they are against the non-mutated coronavirus, vaccinated people are still more protected than those who are unvaccinated. 

According to Public Health England, the Pfizer and AztraZeneca two-dose vaccines are over 90% effective against the delta variant, an efficacy rate similar to the original COVID-19 strain. The study went on to say that a single dose of the vaccine — as offered by Johnson & Johnson — is 17% less effective against variants. Other studies have shown vaccines to be more effective against variants after a second shot. 

In an NPR interview, Dan Barouch, a researcher at the Beth Israel Deaconess Medical Center, explained his recent study which captures the threat posed by the delta variant. Studying 20 vaccinated individuals, he found that the participants’ immune systems were able to neutralize the delta variant and could continue to resist the variant for at least eight months.

Delta, as well as the alpha variant, has become most dangerous in areas where vaccination rates are low.