The largest real-world study assesses the efficacy of a third “booster” dose of the COVID-19 vaccine

The Clarit Institute, in collaboration with researchers at Harvard University, analyzed one of the world’s largest integrated health record databases and administered a third dose of the Pfizer / BioNTech BNT162B2 vaccine against the delta variant of SARS-CoV-2. I checked the effectiveness. This study provides the largest peer-reviewed assessment of the efficacy of a third “booster” dose of the COVID-19 vaccine in a national high-dose vaccination setting. The study was conducted in Israel, an early global leader in the third COVID-19 vaccination rate.

Despite successful vaccination campaigns so far, many countries are currently experiencing a recurrence of SARS-CoV-2 infection. This may be due to the high infectivity of the SARS-CoV-2 delta (B.1.617.2) mutant and the weakened immunity of the vaccine given several months ago. There is sex. In the face of the current resurgence, some countries are planning a third booster dose of the mRNA COVID-19 vaccine.

This study suggests that a third dose of vaccine is effective in reducing severe COVID-19-related outcomes compared to individuals who received two doses of vaccine at least 5 months ago. I am. This is the first to estimate the efficacy of a third dose of the mRNA COVID-19 vaccine-; especially BNT162b2-; with serious results adjusting for a variety of possible confounding factors, including comorbidity and behavioral factors. for. Due to the size of this study, vaccines span different time periods, different subpopulations (depending on gender, age, number of comorbidities), and different serious consequences (rare and require a larger sample size). You can also evaluate the effectiveness of. In a recent clinical trial conducted by BioNTech, the sample size was small and the effect of a third dose on more serious outcomes was not estimated.

This study was conducted from July 30, 2021 to September 23, 2021, in line with the fourth wave of coronavirus infection and disease in Israel, during which the Delta (B.1.617.2) variant was domestically produced. It was a major strain of new infection (with very few exceptions).

The researchers reviewed data from 728,321 people over the age of 12 who received a third dose of the BNT162b2 vaccine. These individuals were carefully matched one-to-one with 728,321 people who had only received two BNT162b2 vaccines at least five months ago. Matching was based on an extensive set of demographic, geographical, and health-related attributes related to the risk of infection, the risk of serious illness, health status, and health-seeking behavior. Individuals were dynamically assigned to each group based on changes in vaccination status (198,476 individuals moved from an unvaccinated cohort to a vaccinated cohort during the study). Multiple analyzes were performed to confirm that the estimated vaccine efficacy was robust against potential bias. The study included a total of over 12,000,000 man-days follow-up studies.

The results show that individuals who received the vaccine three times (more than 7 days after the third dose) were at risk of COVID-19-related hospitalization compared to individuals who received only two doses five months ago. It is 93% lower, showing 92%. The risk of severe COVID-19 disease is low, and the risk of COVID-19-related death is 81% lower. Vaccine efficacy was found to be similar in gender, age group (40-69 years and over 70 years) and number of comorbidities.

The study also included a population-level analysis, which found that infection rates began to decline 7 to 10 days after each age group was eligible for a third dose.

The study was conducted by Dr. Noam Barda, Dr. Noa Dagan, Prof. Cyrille Cohen, Prof. Ran Balicer of the Clarit Institute, and Prof. Miguel Hernán and Prof. Marc Lipsitch of Harvard University TH Chan School. Public Health, Professor Isaac S. Kohane of Harvard Medical School, Professor Ben Wraith of Boston Children’s Hospital and Harvard Medical School.

The large-scale nationwide rollout of Israel’s third “booster” COVID-19 vaccination campaign has led to the Clarit Institute, through its rich and comprehensive digital dataset, of the third vaccination in a real environment. It provided a unique opportunity to evaluate effectiveness. Although less common, it is a serious complication of COVID-19. “

Professor Lan Barriser, Senior Author of Research, Director of the Clarit Institute, and Chief Innovation Officer of Clarit

“These results show that the third dose of vaccine is very effective for severe COVID-19-related results in subgroups of different age groups and populations one week after the third dose. It convincingly shows that. These data should facilitate informed policy making. ” Professor Barriser, who also chairs Israel’s National Expert Advisory Team on COVID-19 compliance.

Professor Ben Wraith, director of the Boston Children’s Hospital Computational Health Informatics Program and the Predictive Medicine Group at Harvard Medical School, said: This careful epidemiological study provides reliable information on the efficacy of the third vaccine. We hope this will help those who have not yet decided on a third vaccination. “

Professor Miguel Hernán, director of CAUSA Lab and professor at Harvard TH Chan School of Public Health, said: “This study is a perfect example of how randomized trials and observational medical databases complement each other. The Pfizer / BioNTech vaccine trial provided convincing evidence of its effectiveness in preventing symptomatic infections, but it was severe. Disease and specific age group estimates were too inaccurate. This analysis of Clarit’s high-quality database emulates the design of the original study and uses the results as benchmarks to extend the randomized trials. This combination of evidence from observational studies and observational studies is a particularly important model for efficient medical research in the COVID era. “

Professor Mark Lipsich, director of the Center for Infectious Disease Dynamics and a professor at Harvard TH Chan School of Public Health, said: The effect is similar for other properties that may predict whether to get infected or get sick. This is especially difficult in the context of vaccine campaigns aimed at rapidly growing ages. Clarit’s extraordinary database allowed us to design studies that address these challenges. A way to give tremendous confidence to the inferences gained from research. “

The study was partially funded by a newly announced collaboration between Ivan and Franceska Berkowitz’s Family Life Institute at Harvard Medical School and the Clarit Institute.

“The enhanced scientific collaboration between Harvard University and Clarit University made possible by the Berkowitz Living Laboratory Collaboration is already fruitful and foresaw the value of a healthcare system useful for research,” said Isaac, the Dean of the Department. Professor Kohane said. Co-Director and Professor Barriser of the Institute of Biomedical Informatics, Harvard Medical School, and the Institute of Family Life in Ivan and Franceska Berkowitz. “Israel offers a unique environment for studying vaccines and their effects. This study is a great example of what can be achieved through such close scientific cooperation.”