Jan 15, 2025
Behavioral and Health Outcomes of mRNA COVID-19 Vaccination: A Case-Control Study in Japanese Small and Medium-Sized Enterprises
Published: December 13, 2024
Understanding the impact of messenger RNA (mRNA) COVID-19 vaccination,
to urgently evaluate the effects,
? COVID-19 infection rates
? related behaviors changes
Results
N = 913 participants
Adjusted ORs for COVID-19 infection among vaccinated individuals, compared to unvaccinated individuals
1.85 (p less than 0.001)
A higher percentage of participants who contracted COVID-19 had received at least one dose of the vaccine
Odds of contracting COVID-19 increased with the number of vaccine doses:
One to two doses, OR: 1.63, (p = 0.020)
Three to four doses, OR: 2.04, (p = 0.001)
Five to seven doses, OR: 2.21, (p = 0.033).
Behavioral analysis indicated that a reduced frequency of bathing and exercising,
was significantly associated with higher COVID-19 infection rates
i.e. bathing frequency and exercising were preventative for infection
Negative efficacy
Conclusions
The study observed a higher reported incidence of COVID-19 infection among vaccinated individuals during the pandemic period
Infections positivily corelated with number of vaccine does
This paradoxical finding may be influenced by various factors,
including immune response mechanisms,
increasing T suppressor (regulatory cells)
antibody-dependent enhancement (ADE),
original antigenic sin,
behavioral changes,
exposure risk.
Understanding these factors is crucial for urgently enhancing public health strategies and vaccination programs.
Methods
A case-control study
Data collected from Japan Small and Medium Enterprise Management Council, December 2023.
Survey gathered information on
demographic characteristics,
COVID-19 infection status,
vaccination history,
health status before January 2020,
various preventive behaviors.
Primary outcome, presence or absence of COVID-19 infection.
Association between vaccination status and COVID-19 infection.
Cleveland Clinic
https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v3
Health-care workers 1,359 unvaccinated,
who had previously tested positive,
non got infected
The study authors concluded:
“individuals who have had SARS-CoV-2 infection are unlikely to benefit from covid-19 vaccination.”
- channel url: https://www.youtube.com/@Campbellteaching
Notable comment to the published article, on their website. copied below:
SADAO SUZUKI, MD, PhD Dec 18, 2024 at 05:34 PM
The paper entitled, ‘Behavioral and Health Outcomes of mRNA COVID-19 Vaccination: A Case-Control Study in Japanese Small and Medium-Sized Enterprises’ written by Dr. Nakatani et al. concludes higher reported incidence of COVID-19 infection among vaccinated individuals than unvaccinated individuals. However, this study raises several concerns that cannot be overlooked.
First, although the title of the study contains “Case-Control Study,” this is not a case-control study. ‘The case-control study starts with a group of cases, which are the individuals who have the outcome of interest. The researcher then tries to construct a second group of individuals called the controls, who are similar to the case individuals but do not have the outcome of interest’ [1]. In this study, however, the researcher first collects whole study subjects and then divides them into two groups: one with outcome and one without outcome. In this respect, the retrospective cohort approach, which divides the entire subject population by exposure, and examines outcome status by exposure group, is more natural and straightforward. Because the authors chose the framework of a case-control study, Table 1 is divided by outcome information, and an important information of the distribution of potential confounders by exposure status is not known.
Second, the primary outcome of this study was the presence or absence of self-reported COVID-19 infection. However, the time frame of the outcome was not questioned and a longitudinal analysis could not be performed. If a subject was infected with COVID-19 before the first vaccination and then received six additional vaccinations and prevented the infection, then vaccination cannot be the cause of COVID-19 infection. In the study, however, the association would be observed between the vaccination and the infection. Without knowing the time frame of the outcome, a causal relationship cannot be discussed.
Third, the study is inadequate in describing important information. Most importantly, all of the subjects were Yamato project participants and/or employees of SMEs, whose attributes were not described at all. Moreover, the actual questionnaire used is not shown, and the specifics of the questions are not clear. For example, we do not know what “eating habits” refers to. Throughout this paper, such descriptions are severely lacking. In addition, the data set is not publicly available.
Fourth, the studies were derived from two different populations, but were combined without assumption. Here, we would like to point out the possibility of confounding due to the different backgrounds of the two groups, Yamato project participants and employees of SMEs. Confounding could occur if the vaccination or infection status of the two groups differs. Adjustment for the groups or confirmation of the absence of confounding is essential.
Fifth, the study population was described by the authors as “the study team believed that the participants reasonably approximated the broader workforce of SMEs in Japan”. However, 504 of the 913 subjects (55.2%) were unvaccinated. Considering that the proportion of unvaccinated persons aged 20 years or older in Japan is 11.6% [2] (as of April 1, 2023), this is a biased population with approximately five times as many unvaccinated persons and is not representative. In this paramount matter, the “reasonable approximation” is completely false. The authors are accountable for the type of population which they chose, why the unvaccinated rate is so high, and with what intent the “reasonable approximation” statement was made.
And last but not least, the validity of the odds ratios is not fully considered. For the odds ratio to be valid, the accuracy of COVID-19 diagnosis must be constant regardless of vaccination status. However, it is conceivable that vaccination is associated with diagnostic diligence for the disease in question, in which case there would be a difference in diagnostic accuracy, resulting in information bias. This bias increases the odds ratio without causality.
References