Dispute between CDC and Ca. contractor on COVID vaccine efficacy statistic
The CDC program COVID-NET tracks the efficacy of COVID vaccination against hospitalization. In its most recent report, the risk of COVID-associated hospitalization was increased by a factor of 16 in those without COVID vaccination compared with those with the bivalent COVID-19 booster for November 2022. That finding was similar to the COVID-NET finding of a reduction in the rate of COVID-associated hospitalization by a factor of 10.5 in a group with the COVID-19 booster for the January-April, 2022. These determinations and others published by COVID-NET have been at the core of the US campaign for COVID vaccination. Alarmingly, a dispute has arisen between the CDC and a member of COVID-NET, the California Emerging Infections Program, on the source of the COVID immunization record used in the calculation of vaccine efficacy.
According the CDC, the COVID immunization status of each study subject is determined by the state immunization information systems. This is stated unambigously in Havers et al.:
“State immunization information system data were linked to cases, and the vaccination coverage data of the defined catchment population were used to compare hospitalization rates in unvaccinated and vaccinated individuals.”
On the other hand, Arthur Reingold, the head of the California Emerging Infections Program, stated in an email:
“For COVID-NET, we track down vaccination using diverse record sources, beyond whatever the individual says.”
The discrepancy between the two versions of the methodology for estimation of this national statistic is extraordinary. Furthermore, there has been significant concern about methodology for the determination of immunization status. In one study, striking discrepancies were found between immunization records from the California Immunization Registry (CAIR) and self-reports. The study postulated the CAIR as the gold standard for the immunization record and found that self-report had a specificity of 87% with a confidence interval of (86–89%) for the determination of immunization. While the differences between self-report and the CAIR were attributed to flaws in self-report, differences could just as easily have been attributed to flaws in the CAIR.
A recent report on the linkage of vaccination status with COVID-associated hospitalization suggests how failure to properly establish vaccination status could wildly inflate vaccine efficacy estimates or create an apparent vaccine effect where none exists whatsoever. In that case, improbable rates of COVID vaccine efficacy were found against all-cause hospitalization.
Given the criminal deceptions of the CDC on COVID vaccine injury, it was never wise to accept CDC estimates of vaccine efficacy at face value. Until ambiguities in the source of CDC vaccine efficacy statistics are resolved, CDC reports on COVID vaccine efficacy should be considered with caution. If, as it appears, the CDC is ignoring state-level, best-evidence adjudication of COVID immunization status in producing the vaccine efficacy estimate, the CDC estimates should obviously be disregarded.