Posted originally on TrialSite New by Dr-Ron-Brown on January 15, 202220

Note that views expressed in this opinion article are the writer’s personal views and not necessarily those of TrialSite.

Proponents of COVID-19 vaccination point out that the increasingly high number of COVID-19 cases in fully vaccinated people simply reflects the greater number of fully vaccinated people compared to unvaccinated people in many populations. To form a more accurate estimation of vaccine effectiveness, the rate of cases within a population needs to be compared between the fully vaccinated and unvaccinated groups—that is, the number of cases in each group divided by the respective total number of people in each group should be compared. Here, I provide an exploratory data analysis, calculating and comparing fully vaccinated and unvaccinated COVID-19 case rates, using an example from COVID-19 vaccination data in Ontario, Canada for January 15, 2022. COVID-19 vaccination data.Subscribe to the Trialsitenews “COVID-19” ChannelNo spam – we promise

COVID-19 cases were reported in Ontario on January 15, 2022 as follows:

Fully vaccinated cases: 8,223

Unvaccinated cases: 1,539

However, the total number of unvaccinated people in the Ontario population who are vaccine eligible (age 5+) is not reported, so that has to be calculated.

From the data, the fully vaccinated population is 11,530,464, and the percentage of fully vaccinated is 82% of the eligible population. 

Therefore, we can estimate the total vaccine eligible population of Ontarians, which is 14,061,541 (11,530,464 / 0.82).

Also from the data, the percentage of unvaccinated people is 12% of the total vaccine eligible Ontarians. 

Therefore, from the total number of eligible Ontarians we can estimate the total unvaccinated population, which is 1,687,384 (0.12 * 14,061,541).

Fully Vaccinated and Unvaccinated Case Rates

Now that we have estimates for the total number of fully vaccinated and unvaccinated Ontarians, we can easily divide the fully vaccinated and unvaccinated cases by their respective number of Ontarians who are fully vaccinated and unvaccinated, giving us the case rates in each group.

Rate of cases in fully vaccinated: 0.07% (8,223 cases / 11,530,464 vaccinated people)

Rate of cases in unvaccinated: 0.09% (1,539 cases / 1,687,384 unvaccinated people)

Absolute reduction of the case rate in fully vaccinated compared to unvaccinated: 0.02%. That’s a difference in case rates of only 2 one-hundredths of 1 percent!

Conclusion: Even though there are many more fully vaccinated people than unvaccinated people in Ontario, the case rate reduction in the fully vaccinated group in this analysis is a mere 0.02% compared to the unvaccinated group. 

According to the vaccine efficacy of the COVID-19 mRNA vaccine clinical trials, the fully vaccinated group should show a 95% case rate reduction compared to the unvaccinated group: Outcome Reporting Bias in COVID-19 mRNA Vaccine Clinical Trials.

The absolute case rate difference between groups based on vaccine status in this exploratory data analysis is negligible.