Author: Guanhao (Alan) Li
As of May 29, 2021, over 1.8 billion doses of vaccines were delivered to the masses globally1. Big pharmaceutical companies promoted their vaccines by using a terminology called “efficacy”, a word to describe how effective the vaccine protects people from being infected. However, the term “efficacy” is flawed, as the term only describes RRR (Relative Risk Reduction) while neglects ARR (Absolute Risk Reduction).
Relative risk reduction does not fully convey the efficacy of vaccines. In clinical trials, conductors separated volunteers into two groups. Participants in experimental group received vaccines, while the invitees in control group got some form of injection8. Relative Risk Reduction then compared the rate of infections in experimental group and control group. A specific formula calculates the relative risk and relative risk reduction.
According to NIH, invited participants for phase 3 of Moderna mRNA-1273 clinical trial resided in high-risk areas with a higher chance of exposure to the COVID-198. However, in clinical trials for Moderna and Pfizer-BioNTech vaccines, only a relatively small number of people contracted the virus, no matter which group they belonged to2. More importantly, the relatively small sample sizes (43,440 in Pfizer trials and 30,420 in Moderna trials) in both trials did not fully represent the actual COVID-19 pandemic situation at a larger scale2, 9. Hence, for individuals, one more calculated formula involving difference between rate of infection in two groups will provide a deeper insight into the data.
Absolute Risk Reduction, along with RRR, will help individuals make critical decisions when choosing to get vaccinated. Formula of ARR is as follows:
As a medical term, absolute risk means the chance of getting a disease over time. To further illustrate, a 10% chance of getting a disease translates into an absolute risk of 0.13. Absolute risk reduction refers to an arithmetic difference in event rates between two groups4. However, in a more common sense, ARR numerically measures reduced chance of receiving the disease. According to a peer-reviewed study published on Lancet, ARR for all experimental COVID-19 vaccines were lower than 2%5. Specifically, Pfizer-BioNTech BNT162b2 returned the lowest ARR of 0.84%5. Although the real efficacy of currently available COVID-19 vaccines needs to be further studied by the experts, the nearly negligible ARR informs people that none of vaccines will prevent an individual from contracting the virus eventually.
Thus, people can clearly tell that vaccine manufacturers have hidden some secrets of their doses. Adding up to the facts that government and big media are currently working hard suppressing information regarding serious side effects of vaccines6, 7, everybody must carefully evaluate the risk of immunization.
1. CTVNews.ca staff. Coronavirus vaccination tracker: How many people in Canada have received shots? ctvnews.ca, https://www.ctvnews.ca/health/coronavirus/coronavirus-vaccination-tracker-how-many-people-in-canada-have-received-shots-1.5247509 (2021)
2. Ronald B. Brown. Outcome Reporting Bias in COVID-19 mRNA Vaccine Clinical Trials. mdpi.com, https://www.mdpi.com/1648-9144/57/3/199/htm (2020)
3. Louise Newson, Cathy Jackson. Calculating absolute risk and relative risk. patient.info, https://patient.info/news-and-features/calculating-absolute-risk-and-relative-risk (2018)
4. UWA Medical and Dental Library, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia. Understanding absolute and relative risk reduction. uwa.edu.au, https://www.meddent.uwa.edu.au/__data/assets/pdf_file/0005/2670593/Risk_reduction_guide0.2.pdf
5. Olliaro, P. et al. COVID-19 vaccine efficacy and effectiveness—the elephant (not) in the room. thelancet.com, https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(21)00069-0/fulltext (2021)
6. Tyler Durden. Facebook Whistleblowers Reveal Campaign To Censor Vaccine Hesitancy. zerohedge.com, https://www.zerohedge.com/covid-19/facebook-whistleblowers-reveal-campaign-censor-vaccine-hesitancy (2021)
7. Cosmin Dzsurdzsa. BC doctor stripped of ER shifts after raising COVID vaccine side effect concerns. tnc.news, https://tnc.news/2021/05/25/bc-doctor-stripped-of-er-shifts-after-raising-covid-vaccine-side-effect-concerns/ (2021)
8. ModernaTX, Inc. A Study to Evaluate Efficacy, Safety, and Immunogenicity of mRNA-1273 Vaccine in Adults Aged 18 Years and Older to Prevent COVID-19. clinicaltrials.gov, https://clinicaltrials.gov/ct2/show/NCT04470427 (2020)
9. Centers for Disease Control and Prevention. COVID Data Tracker. covid.cdc.gov, https://covid.cdc.gov/covid-data-tracker/#datatracker-home (2020)