A booster shot of the covid vaccine adds significant protection against infection and severe illness, Israeli officials have found.

The results from an analysis by the Health Ministry of the effects of a third Pfizer jab have given new hope as Israel battles against the Delta variant that is sweeping the world.

The study looked at over-60s – who were first to get the vaccine in December, as Israel’s pioneering inoculation roll-out got going.

After a renewed surge of infections blamed on the Delta variant and with levels of immunity found to be falling in some patients, Israel began to administer a third shot to the over-60s last month.

Experts compared those who had just the two jabs, and those who were given the further ‘booster’. The data showed the extra jab provided four times higher protection against infection just 10 days after it was given.

The booster was even more effective in stopping severe illness and hospitalisation, with protection multiplied by five to six times.

The findings were published on the government website on Sunday.