By Michael Tomlinson at Brownstone dot org.

If there is one thing we have learned since 2020 it is the power of confirmation bias. The public health establishment has presented a mass of data and analysis to show that it was right all along about the Covid-19 pandemic and saved millions of lives. This finding has been accepted at face value and incorporated into policy, but rests on shaky foundations.

We need to look at the big picture. Apologists for vaccination generally use point-to-point comparisons – they pick an arbitrary date near the peak of the epidemic curve and compare it to a later date to show that an intervention is correlated with a reduction in infections or mortality. This is open to case-counting window bias and immortal time bias – another selection of dates could yield an entirely different result.

To counteract this, we need to look at the epidemic curve as a whole and see whether the intervention changed its trajectory.

What we see in the Euromomo statistics of European all-cause mortality below, is a series of declining peaks and broadening curves after the anomalous peak in April 2020. All-cause mortality is crucial, as it avoids distortion due to misclassification of deaths between Covid-19, vaccine adverse effects, and other causes of death.

There was a gradual return to a more normal pattern, usually attributed to a combination of increasing natural immunity and the effects of vaccination. This falls far short of the exaggerated claims made for vaccination when the first clinical trial results were released. We were told by political and public health leaders that vaccination gave 95% protection, a figure that was based on the rate of Covid-19 symptoms paired with positive PCR tests in the vaccine group, compared with the placebo group. It was not based on improved mortality.

Vaccination may have contributed to the improving trend, but there is no basis for finding that it was solely responsible for returning to a more normal seasonal pattern of mortality. And hidden in the count of all-cause excess mortality may be deaths caused by Covid-19 vaccination. There is no way of excluding this possibility.

For example, vaccine-related deaths could be driven through cardiac adverse events. The Cohort study of cardiovascular safety of different Covid-19 vaccination doses among 46 million adults in England by Ip et al showed that incidence rates of cardiovascular events were substantially higher (nearly double for arterial events) after the first dose of the Pfizer and AstraZeneca vaccines, compared to no vaccination (Table 2).

The authors then concluded the opposite by adjusting the figures. But they selectively only employ adjustment factors that place downward pressure on vaccine hazard ratios, and ignore factors that might exert upward pressure, such as the well-known healthy vaccinee bias.

Chemaitelly et al corrected for this by assessing the association between Covid-19 vaccination and non-Covid-19 mortality as a control. They found that 'A pronounced healthy vaccinee effect was observed during the first 6 months following vaccination, despite meticulous cohort matching,' possibly due to seriously ill individuals not being suitable candidates for vaccination and so being underrepresented in the vaccinated group.

Some studies adjust for case-counting window bias or immortal time bias, but healthy vaccinee bias is too problematic to correct, so the full range of confounding effects is not brought to bear on the results, leaving the field to partially corrected studies which may be more misleading than uncorrected results.

Finding our way through this maze is difficult and the mass of observational studies are not a reliable basis for public health policy.

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