2 Pfizer COVID-19 shots 95% effective in preventing infection - study
This new study, which reported on national data for the first time, indicates that vaccines can help control the pandemic.
By MAAYAN JAFFE-HOFFMANA healthcare worker hands over doses of the Pfizer-BioNTech COVID-19 vaccine to a doctor at Messe Wien Congress Center, which has been set up as coronavirus disease vaccination centre, in Vienna, Austria February 7, 2021.(photo credit: REUTERS/LISI NIESNER/FILE PHOTO)
Two doses of the Pfizer vaccine are “highly effective” at preventing infection, hospitalization or death by COVID-19, a new observational study published by the Health Ministry’s Department of Epidemiology showed.Published on Wednesday in the prestigious Lancet medical journal, the study also showed that Israel’s infection rates substantially declined in correspondence with an increase in vaccine coverage.This means that COVID-19 vaccination can help control the pandemic, Prof. Eyal Leshem, director of the Center for Travel Medicine and Tropical Diseases, told The Jerusalem Post.He and his colleague, Annelies Wilder-Smith of the Department of Disease Control at the London School of Hygiene & Tropical Medicine in London, analyzed the study for The Lancet.Israel administered 10 million doses within four months.Israel is the first country to publish national data showing these vaccine benefits, Leshem said. He noted that the report also highlights that the vaccine is equally as effective for all cohorts, including elderly people over the age of 75.Specifically, the report showed that at seven days or more after the second dose, the vaccine was 95.3% effective against coronavirus infection, 91.5% against asymptomatic coronavirus, 97% against symptomatic coronavirus, 97.2% against hospitalization and 96.7% against death.Asymptomatic infection was defined as a person with a laboratory-confirmed infection but no fever or respiratory symptoms. Individuals were defined as fully vaccinated if at least seven days had passed since they received two doses of the vaccine.The Israeli results were even slightly higher than those shown in the Pfizer clinical trials. A spokesperson for the Health Ministry told the Post that it is not possible to directly compare numeric results from a clinical trial to an observational study because the randomized nature of a clinical trial minimizes various sources of bias while an observational study such as the one performed in Israel can be subject to bias that can affect results in either directions.“The advantage of an observational study shows what happens in the real world,” the spokesperson said.
The study analyzed nationwide data from between January 24 and April 3, 2021, a period in which Israel was experiencing one of its largest virus outbreaks, with an average of 8,328 new infections per day that peaked at 10,213 on January 20.According to the Lancet article, Israel experienced a “rapid decline” in COVID-19 infection from March 2021 onwards until on April 19, the seven-day moving average of new cases dropped to 149 new cases per day.Even when the country reopened and normal activities largely resumed, daily cases remained low, providing “nationwide evidence of the beneficial public health impact of a COVID-19 vaccination campaign,” the report said.The study also found that one dose of the vaccine provided a 58% chance of protection against infection, 76% likelihood of avoiding hospitalization, and 77% likelihood of avoiding death, ranging from 14 to 21 days after receiving the shot. The authors of the study noted that the British variant constituted more than 95% of COVID-19 cases in Israel during the time of the study and therefore it is unclear if the vaccine is effective against other variants of concern.The Health Ministry told the Post that the data could help Pfizer to get full approval by the US Food and Drug Administration for its vaccine, which now is only approved for emergency use.“Regulatory organizations use all available data when approving new drugs including vaccines,” the spokesperson said. “We believe that Israel’s rigorous national database gives the opportunity to evaluate vaccine effectiveness on the macro level, and this critical information will be significant in future decision-making.”"The beneficial results of the vaccine presented in this publication from experience in the State of Israel give real hope that the vaccine will enable control of the pandemic throughout the world,” Head of Public Health Services Dr. Sharon Alroy-Preis said.However, the success of Israel’s vaccination campaign cannot be easily replicated in many other countries, the authors of the study noted.“The global use of the [Pfizer] vaccine is limited by supply issues, high costs, and ultra-cold chain storage requirements,” the report said.When asked if the data would encourage Israel to vaccinate the Palestinians to help ensure its border crossings remain safe, the ministry responded that “Israel sees great importance in controlling the pandemic worldwide and certainly in neighboring populations. Israel will continue to assist Palestinians in receiving effective and safe COVID-19 vaccinations at all opportunities.”
