Related Experiment Video
Updated: Sep 7, 2025
Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice
Published on: February 22, 2019
Plausibility of Claimed Covid-19 Vaccine Efficacies by Age: A Simulation Study
Kyle A Sheldrick1, Gideon Meyerowitz-Katz2, Greg Tucker-Kellogg3
1Faculty of Medicine, University of New South Wales, Kogarah, Australia.
Insights
The Sputnik V vaccine
Area of Science:
- Immunology
- Vaccinology
- Biostatistics
Background:
- Concerns exist regarding the reported efficacy of the Sputnik V vaccine across different age groups.
- Phase-3 trials for multiple COVID-19 vaccines have concluded, providing efficacy data.
- Investigating age-specific vaccine efficacy is crucial for public health.
Purpose of the Study:
- To assess the statistical likelihood of observed age-specific efficacies for major COVID-19 vaccines.
- To determine if the reported Sputnik V vaccine efficacy distribution across age groups is plausible.
- To compare the age-group efficacy patterns of Sputnik V against AstraZeneca, Janssen, Moderna, and Pfizer vaccines.
Main Methods:
- A simulation study was conducted using R software.
- 1,000 and 50,000 simulated trials were performed for each vaccine.
- Simulations assumed random allocation, fixed enrollment by age, and study-wide efficacy rates.
Main Results:
- For Sputnik V, 0.0% of 1,000 simulated trials showed all age subgroups within reported efficacy bounds.
- In 50,000 simulations, only 0.026% of Sputnik V trials had all age subgroups within reported efficacy limits.
- Other vaccines (AstraZeneca, Janssen, Moderna, Pfizer) showed higher probabilities of observed efficacies falling within reported ranges.
Conclusions:
- The reported age-specific efficacy distribution for the Sputnik V vaccine is statistically highly improbable.
- Genuine experimental data is unlikely to produce the observed efficacy patterns for Sputnik V, even with true efficacy and infection rates.
- The findings raise questions about the reliability of the Sputnik V vaccine's reported age-stratified efficacy.
Background:
Multiple vaccines against Covid-19 have passed through phase-3 trials; however, concerns have been raised about alleged excessive similarity of efficacy across age groups for the Sputnik V vaccine.
Study Question:
How likely are the observed efficacies for all age subgroups to fall within the range of by-age efficacies claimed for the AstraZeneca, Janssen, Moderna, Pfizer, and Sputnik V vaccines, assuming that there is no effect of age on efficacy?
Study Design:
We performed a simulation study using R of 1000 and then 50,000 simulated trials for each vaccine, with random allocation to each arm but fixed enrollment numbers by age group. We used study-wide efficacy and infection rate for all age groups. We recorded the observed vaccine efficacies in each age group and summated how many simulations had all observed efficacies fall within the range of efficacies described in the relevant article.
Results:
In the 1000-trial simulation for the AstraZeneca vaccine, in 23.8% of simulated trials, the observed efficacies of all age subgroups fell within the efficacy bounds for age subgroups in the published article. The J + J simulation showed 44.7%, Moderna 51.1%, Pfizer 30.5%, and 0.0% of the Sputnik simulated trials had all age subgroups fall within the limits of the efficacy estimates described by the published article. In 50,000 simulated trials of the Sputnik vaccine, 0.026% had all age subgroups fall within the limits of the efficacy estimates described by the published article, whereas 99.974% did not.
Conclusions:
The distribution of alleged vaccine efficacies of the Sputnik vaccine by age in the phase-III trial is very unlikely to occur in genuine experimental data, even if the number of patients recruited, vaccine efficacy, and overall infection rate are true and there is no underlying difference in vaccine efficacy by age.
More Related Videos
12:21A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness
Published on: September 28, 2022
08:52Use of an Influenza Antigen Microarray to Measure the Breadth of Serum Antibodies Across Virus Subtypes
Published on: July 26, 2019
Related Concept Videos
01:51Vaccinations
01:20Actuarial Approach
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...