The Delta variant of COVID-19 is spreading so rapidly in the U.S. that it will likely become the dominant strain in weeks, according to U.S. scientists.

The spread of the variant was first detected in India, and is the most contagious and lethal, and can cause more severe illness than other variants.

Currently, the Delta variant accounts for at least 14% of all new infections, according to the research analysis posted online Monday of more than 242,000 infections nationwide over the last six months.

U.S. scientists are concerned that the fact that the variant is so transmissible means it's dangerous, and outbreaks around the country are likely.

The FDA authorized vaccines appear, in general, to provide good protection against all the variants, including Delta. However, there is a lot of concern due to the accelerated growth of infections from the variant because of the large number of unvaccinated people.

Medical experts worry the Delta variant could trigger another surge of infections through the country, especially in states that have low rates of vaccinated people. Projections indicate that as the vaccinations continue to decline, infections could start to rise again by July. Read the full NPR article here.