Update Date: February - 2023
In part 5 of our US disabilities analysis, we compared the rise in disability rates post 2/2021 with the analysis of Serious Adverse Events (SAEs) performed in the paper by J. Fraiman et al. in Vaccine journal, where they average the rates of SAEs of both the Pfizer and Moderna clinical trials. We showed that the projected rate of SAEs tends to underestimate the rise in disabilities observed at a population level.
In this part, we expand on the previous analysis by investigating the rates of adverse events (AEs) and Severe Adverse Events (Sev AEs) for the Pfizer trial. These were published in table S3 of the supplementary appendix of the paper by S. J. Thomas et al. that established the vaccine efficacy ("Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months", in New England Journal of Medicine, 9/2021).
A subgroup of participants was monitored for adverse events using an electronic diary for 7 days after each dose, and all participants’ adverse events were recorded from dose 1 to 1 month after dose 2. These latter AEs are described as being ‘unsolicited’ as they were not prompted by the electronic diary. The AEs were measured from August 2020 to December 2020, before the unblinding of the clinical trial. The severity of these adverse events was considered to be mostly mild or moderate.
Summary of the main adverse events
The numbers in the table below were obtained from table S3 of the paper's supplementary appendix. It summarises the Adverse Events during the blinded follow-up period (from dose 1 to 1 month after dose 2) in the Pfizer trial. The yellow shaded cells refer to computed values.
|Adverse Event||Vaccine (N=21,926) (%)||Placebo (N=21,921) (%)||Risk Difference||Risk Ratio|
|Any Event||6617 (30.2)||3048 (13.9)||3569|
|-Related||5241 (23.9)||1311 (6.0)||3930|
|-Severe||262 (1.2)||150 (0.7)||112|
|-Life-threatening||21 (0.1)||26 (0.1)||-3||Total Events (per 10,000) - Computed Values|
Severe adverse events (Sev AEs).
Assumptions for computing the Severe AEs time series:
-> The initial monthly rate of excess Sev AEs corresponds to 51.1 per 10,000 (the rate computed in the table above) divided by the median observation period of 2 months.
-> After 2 months the rate of SAEs falls to 1/2 of the original value and after 4 months it falls to 1/4 of the original rate. After 6 months we assume that the rate of SAEs falls to 1/10 of its original value.
-> The assumptions are based on the thought that different types of severe or serious events could occur over an extended period, but also that most events will be front-loaded. As Sev AEs are not as extreme as SAEs, we assumed a faster drop-off in the rate of events that would lead to a disability over time. The terminal rate of 1/10th of the original value attempts to capture the possibility of longer-term effects. These assumptions constitute our best guesses, and both the starting rate of Sev AEs and the assumption of how they decay (drop off) over time, could be adjusted as more information becomes available.
Severe Adverse events (Sev AEs) have a broader range of definition than Serious Adverse Events, resulting in higher numbers of Severe AEs being reported, as we can observe from the table above.
The chart on the left shows the time series of the change in disability rate from 2/2021 to 11/2022 for the Civilian Labor Force (left scale), and also the time series of the projected rate of Severe AEs from the Pfizer trial. For comparison it also shows the inferred rate of Serious Adverse Events (SAEs) from the combined Pfizer and Moderna trials, which was discussed previously in part 5.
The chart on the right shows the correlation between the rise in the disability rate since 2/2021 and the projected cumulative rate of Severe AEs for the Pfizer trial. The regression R2 is around 88% which is evidence for a strong relationship.
We can observe that the rate of rise in disabilities is very close to the computed rate of excess Severe AEs. We observe that there are 1.34 more projected Severe AEs than the rate of rise in disabilities implying that most Severe AEs could eventually lead to a disability. The rise in the rate of disabilities reported by the individuals surveyed by the BLS lies in between the projected rate of SAEs based on analysis of the combined Pfizer and Moderna trials, and the rate of projected Severe AEs based on those reported in the Pfizer clinical trial.