With the Delta variant of the coronavirus now a new cause of concern for the world, focus shifts on how well available COVID-19 vaccines are in protecting anyone. Over in Israel, it appears that the efficiency level of the Pfizer-BioNTech jab has dropped.

In a statement released on Monday, the Israeli government claims that the Pfizer vaccine was found to be less effective against the said strain, CNN reported. The vaccine provided only 64% protection, a big drop from the 95.3% efficiency against all infections in May.

Further, the government added that the jab was now 93% effective in preventing severe disease and hospitalizations, compared to 97% that was reported in The Lancet in May.

No details were revealed to support the claim. However, a team from the Hebrew University cautioned that it was too early to tell how much the Delta variant was affecting the Pfizer vaccine’s efficacy. Regardless, the public is still encouraged to get vaccinated to have some level of protection against the virus, especially in severe cases.

"Best data still suggest mRNA vaccines offer high degree of protection against infection and superb protection against severe illness. Lets await more data but as of now ... If you're vaccinated, I wouldn't worry," Dr. Ashish Jha, dean of Brown University's School of Public Health tweeted.

Israel deployed the Pfizer vaccine to most in the country over the age of 12. The early and quick rollout allowed scientists a picture to determine its efficacy.

Concern grows on the Delta variant, a more infectious strain that was first discovered in India. It is also known as B.1.617.2. Israel is one of the most vaccinated countries in the world with more than 60% of the population fully inoculated and about two-thirds having gotten the first dose.

For their part, Pfizer could not comment on the unpublished data. Based on a published lab study conducted with the University of Texas Medical Branch, the vaccine remains effective against lab-made versions of the Delta strain and others.

Pfizer COVID-19 vaccine This illustration picture taken on November 23, 2020 shows a bottle reading "Vaccine Covid-19" and a syringe next to the Pfizer and Biontech logo. - The European Commission has signed five contracts to pre-order vaccines, among which with the U.S.-German company Pfizer-BioNTech (up to 300 million doses). JOEL SAGET/AFP via Getty Images