Two doses of the COVID-19 vaccines made by Pfizer-BioNTech or AstraZeneca are "highly effective" against variants first detected in India and the United Kingdom, health officials in England announced Saturday.

Why it matters: Some health experts have expressed concerns that contagious new variants could be more resistant against coronavirus vaccines, potentially prolonging the pandemic.

By the numbers: Public Health England, an executive agency of the U.K. Health Department, said in a statement Saturday that research conducted from April 5 to May 16 found that:

• Two weeks after the second dose, the Pfizer-BioNTech vaccine was 88% effective against symptomatic disease from the B.1.617 variant first detected in India. It's 93% effective against the B.1.1.7 variant first found in England.
• Two doses of the AstraZeneca vaccine were "60% effective against symptomatic disease from the B.1.617 variant compared to 66% effectiveness against the B.1.1.7 variant."
• Both vaccines were 33% effective against symptomatic disease from B.1.617, three weeks after the first dose compared to roughly 50% effectiveness against the B.1.1.7 variant.

What they're saying: Public Health England said in the statement that "we expect to see even higher levels of effectiveness against hospitalization and death" in regards to these vaccines.

• U.K. Health Secretary Matt Hancock said in the statement that due to this "groundbreaking" research gave officials confidence that those vaccinated against the coronavirus "have significant protection against this new variant."

The big picture: The World Health Organization has called the B.1.617 coronavirus mutation a "variant of concern."

• Health experts expect this variant to soon become the "dominant strain" in the U.K., with Hancock reporting a surge in B.1.617 cases — describing the situation as a "race between the virus and the vaccine," per the Guardian.
• German authorities have imposed a ban on most non-essential travel from the U.K. from Sunday to prevent the spread of new variants in the country.

Go deeper: The race to avoid a possible "monster" COVID variant