Israel's largest healthcare provider is reporting a 94% drop in symptomatic COVID cases among people who have received the Pfizer vaccine.
The study is the country's largest to date, being conducted among 600,000 people who received two doses.
The group was also found to be 92% less likely to develop severe illness from the virus.
Clalit, the healthcare provider that conducted the study, covers more than half of all Israelis.
Clalit's chief innovation officer said, quote, "It shows unequivocally that Pfizer's coronavirus vaccine is extremely effective in the real world a week after the second dose."
Israel is driving one of the world's fastest vaccine rollouts, and is being watched closely because its database offers real-world insights into how effective the vaccines are outside of clinical trials.
Researchers at the Weizmann Institute of Science have been crunching national data.
They've seen a sharp decline in hospitalization and serious illness among the first group to be vaccinated - people aged 60 or above.
Hospitalizations and serious illness are still rising in younger groups, though - who began vaccinations weeks later.