Israeli study finds 94 pct drop in symptomatic COVID-19 cases with Pfizer vaccine

Health maintenance organization (HMO) Clalit, which covers more than half of all Israelis, said the same group was also 92% less likely to develop severe illness from the virus.

The comparison was against a group of the same size, with matching medical histories, who had not received the vaccine.

"It shows unequivocally that Pfizer's coronavirus vaccine is extremely effective in the real world a week after the second dose, just as it was found to be in the clinical study," said Ran Balicer, Clalit's chief innovation officer.

He added that the data indicates the Pfizer vaccine, which was developed in partnership with Germany's BioNTech, is even more effective two weeks or more after the second shot.

Researchers at the Weizmann Institute of Science, who have been tabulating national data, said on Sunday that a sharp decline in hospitalisation and serious illness identified earlier among the first age group to be vaccinated - aged 60 or older - was seen for the first time in those aged 55 and older.

Hospitalisations and serious illness were still rising in younger groups who began vaccinations weeks later.