A coronavirus vaccine developed by Pfizer / BioNTech is 85% effective in preventing people who develop Covid-19 symptoms after the first dose, a study by Israeli health workers has shown.
The results, published in the Journal of the Lancet, appear to confirm the UK’s decision to postpone the second dose of the Pfizer vaccine – given the high level of protection before the first shot – to increase the number of people who get the sting receive.
The scientists also found that all infections, including those with no symptoms, were reduced by 75% after the first dose.
More than 7,000 healthcare workers at Sheba Medical Center in Israel – the largest hospital in the country – were involved in the study.
Commenting on the study, Deborah Dunn-Walters, Chair of the British Society for Immunology Covid-19 and Immunology Taskforce and Professor of Immunology at the University of Surrey, commented on the study: “Due to the high percentage of the previously vaccinated Israeli population, we have access to data from there waited to show the first signs of how effective Covid-19 vaccines are outside of a clinical trial and how the dosing schedule affects them. “
She added, “It should be noted that this study was conducted on people of working age. Hence, it is informative to see a similar study in the elderly after a dose.
“While more research is needed, these new findings should, taken as a whole, confirm the UK’s decision to offer the two doses of vaccine every 12 weeks.
“While the results of this study show that there is a good level of immunity after one dose of the Pfizer / BioNTech vaccine, the highest and longest lasting protection against disease with Covid-19 is only obtained from providing two doses of the vaccine.
“It is important that all individuals eligible for Covid vaccination return to receive their second dose when instructed to do so by their healthcare providers.”
Dr. Peter English, advisor on communicable disease control and former editor of Vaccines in Practice Magazine, described the results as “good news” but added that the data available are “quite limited”.
He said, “This is good news. It supports previous data suggesting that the effectiveness of the vaccine will be at least 85% – possibly significantly better – from about six weeks after vaccination, at least for vaccine recipients of working age.
“This is more of a letter than a research report – so the data are quite limited and I would expect far more details to be released in due course.”
Dr. English added, “As far as I can tell, this particular letter does not contain any data on severe and mild infections. Based on other evidence (and general experience with vaccination), we would expect vaccination to be more protective against serious illness than against mild illness and more protective against mild illness than against asymptomatic infection.
“We may see more information on this when a more complete release becomes available.”