Immunity derived from the first dose of the Covid-19 vaccine could be as low as 33 per cent, said the deputy chair of the Joint Committee on Vaccination and Immunisation (JCVI).

JCVI deputy chair Professor Anthony Harnden has said he is analysing the data from the research carried out in Israel that seems to suggest that two doses of Pfizer/BioNTech vaccine are needed to secure high levels of immunity, Yahoo News reported.

Also read: Covid-19 vaccinated people should also be cautious, immunity takes time to kick in: Expert

Prof Anthony Harnden believes that the second dose should be delayed and be given 12 weeks apart in order to help the maximum number of people acquire some protection as the vaccine supplies are limited.

He added that the Israel study suggested the vaccine’s full efficacy can only be harnessed when the two doses were given at least 21 days apart, The Guardian reported.

In an interview with Sky News, he said: “We will be looking at this (Israel-based study) in detail but at the moment our clear steer is the delayed second dose strategy is going to save many lives nationally.”

Also read: Vaccinating people over 60 is the best way to mitigate Covid-19 crisis: Study

In December, the JCVI, which is advising the British government on the vaccine roll-out, had noted that the efficacy of the Pfizer vaccine was “around 90 per cent”, starting 14 days after the first dose. It had further claimed the “short-term protection from dose one is very high.”