The Covid vaccines work to reduce the severity of disease with various degrees of success.

We have literally no good evidence for this. The evidence we have is badly tainted and should be treated as, at best, possible but not proven.

• The studies on the Covid vaccines were all performed by the companies with financial interest in them succeeding;
• and then approved by regulators who have either been captured by the companies they are supposed to regulate;
• or have direct and indirect financial incentives to approve the vaccines;
• the Pfizer studies in particular have serious allegations of fraud and scientific misconduct raised against them by whistleblowers and others.

There are all sorts of statistical shenanigans that have been used to shift the numbers to make the vaccines seem more effective. One very common trick is to count any death, regardless of cause, as a Covid death if it occurs within two weeks of a positive Covid test.

In Israel, hospitals would test every patient for Covid if they were unvaccinated but only test the vaccinated if they were showing Covid-like symptoms. That boosts the number of reported "Covid deaths" among the unvaccinated, making the vaccinated cohort look better in comparison.

Another trick is counting deaths in the first two weeks after vaccination as "unvaccinated".

All of these tricks make the vaccines appear better at preventing serious disease than they really are, and over-inflate the number of unvaccinated Covid deaths, making the disease seem more dangerous than it really is.

Another factor, I presume due to panic rather than malice, is that many of the early Covid deaths were due to poor medical treatment contributing to the deaths, if not outright being the cause of the death:

• Remdesivir has kidney failure as a known side-effect, was one of the only approved treatments for Covid in the early months. During that time, the media was full of reports of how Covid patients (being treated with Remdesivir) were dying of kidney failure, and the blame put on the virus.
• Lung damage and other complications from early intubation (ventilators), including secondary bacterial pneumonia which (in contrast to the previous SARS outbreak) was often not treated with antibiotics.
• Early in the pandemic, when patients where being routinely intubated, there were many cases of multi-organ failure due to a cytokine storm. Now that patients are only rarely intubated, and then much less aggressively, deaths from cytokine storm has all but disappeared. Guess which treatment can cause a deadly cytokine storm?

This made the early Covid strains seem much more deadly than they really were, and by extension made the vaccines seem better at reducing severe illness.