Report: Pfizer jab 85% effective after first dose for Israeli healthcare workers

Study in Lancet journal provides reassurance about UK's delay of second dose, after 7,000 healthcare workers at the Sheba Medical Centre show 75% fall in infection after one jab

A coronavirus vaccine developed by Pfizer/BioNTech is 85% effective at preventing people developing Covid-19 symptoms after the first dose, a study of Israeli healthcare workers has shown.

The findings, published in the journal Lancet, appear to provide reassurance about the UK’s decision to delay the second dose of the Pfizer vaccine – given the high level of protection from the first shot – in order to increase the number of people getting the jab.The scientists also found that all infections, including those without symptoms, were reduced by 75% after the first dose.More than 7,000 healthcare workers at the Sheba Medical Centre in Israel – the country’s largest hospital – were involved in the study.

Commenting on the research, Deborah Dunn-Walters, chairwoman of the British Society for Immunology Covid-19 and Immunology Taskforce and professor of immunology at the University of Surrey, said: “Due to the high percentage of the Israeli population vaccinated so far, we have been awaiting data from there to indicate the first signs of how effective Covid-19 vaccines are outside of a clinical trial setting and how dosing schedule plays into this.”

She added: “It should be noted that this study was carried out on people of working age, so it will be informative to see a similar study in older people after one dose.

“Although further research is needed, overall these new findings should provide reassurance around the UK’s decision to offer the two doses of the vaccine 12 weeks apart.

“While the results of this study show that a good level of immunity is present after one dose of the Pfizer/BioNTech vaccine, it is still the case that the highest and longest lasting protection from getting ill with Covid-19 will only be provided by getting two doses of the vaccine.

“It is critical that all people eligible for Covid vaccination do return to get their second dose when asked to do so by their medical providers.”

Dr Peter English, consultant in communicable disease control and former editor of Vaccines in Practice Magazine, described the findings as “good news” but added that available data is “quite limited”.

He said: “This is good news. It supports earlier data suggesting that, from six weeks or so after vaccination, vaccine efficacy is likely to be at least 85% – possibly considerably better – at least in vaccine recipients of working age.

“This is a letter, rather than a research paper – as such the data are quite limited, and I would expect far more details to be published in due course.”

Dr English added: “As far as I can tell, this particular letter does not include data on severe and mild infection – from other evidence (and experience with vaccination more generally) we would expect the vaccination to be more protective against severe disease than against mild disease, and more protective against mild disease than against asymptomatic infection.

“We may see more information on this when a more complete publication is made available.”