Pfizer Vaccine Effectiveness Drops Sharply from 94% to 64% Against Delta Variant

Israel's New Infections: 55% Breakthrough Cases from Delta Variant

Since June 1, Israel lifted most of its quarantine measures, but as the Delta variant rapidly spread mainly among unvaccinated adolescents under 16, mask-wearing was made mandatory again after just ten days. The photo shows a testing site in Binyamina, Israel, where a COVID-19 test is being conducted. Photo by Yonhap News/AP

[Asia Economy Reporter Kim Heeyoon] A study has found that the effectiveness of the Pfizer vaccine in preventing COVID-19 sharply declined following the spread of the Delta variant (originating from India).

On the 5th (local time), Israeli media outlet Ynet reported research results showing that while the Pfizer vaccine had a 94% prevention efficacy against the original COVID-19 virus, its effectiveness is much lower against the Delta variant.

Earlier, the Israeli Ministry of Health announced that from May 2 to June 5, the Pfizer vaccine’s COVID-19 prevention efficacy was 94.3%. However, clinical trial results from June 6 to July 3 showed that the Pfizer vaccine’s prevention efficacy dropped to 64%.

During the same period, the Pfizer vaccine’s efficacy in preventing severe cases fell from 98.2% to 93%. Additionally, Ynet added that more than half (55%) of new infections were confirmed as breakthrough infections in fully vaccinated individuals.

Israel confirmed its first case of the Delta variant on April 16. Since then, the Delta variant rapidly spread mainly among unvaccinated individuals. From June 1, Israel lifted most of its quarantine measures, and on June 15, it also lifted the indoor mask mandate.

However, immediately after lifting the measures, cluster infections among unvaccinated children and adolescents under 16, especially in schools, continued. Recently, over 300 new daily cases have been reported. In response, the Israeli government reinstated the indoor mask mandate within ten days.

Local media analyzed that the government’s complete lifting of quarantine measures before the spread of breakthrough infections caused by the Delta variant, which can evade vaccine protection, was the cause of the resurgence.

A senior official from the Israeli Ministry of Health said, "It is concerning that the vaccine appears to be less effective against the Delta variant," and added, "The government should consider providing booster shots to the elderly with weakened immune systems."

Meanwhile, the World Health Organization (WHO) has recommended that even vaccinated individuals wear masks indoors as the Delta variant spreads worldwide.

This content was produced with the assistance of AI translation services.