Prof Harald Walach is well-known to regular readers of this blog (see, for instance, here, here, and here). Those who are aware of his work will know that he is not an expert in infectious diseases, epidemiology, virology, or vaccinations. This did not stop him to publish an analysis that questions the safety and rationale of the current COVID-19 vaccination programs. Here is the abstract:

COVID-19 vaccines have had expedited reviews without sufficient safety data. We wanted to compare risks and benefits.

Method: We calculated the number needed to vaccinate (NNTV) from a large Israeli field study to prevent one death. We accessed the Adverse Drug Reactions (ADR) database of the European Medicines Agency and of the Dutch National Register ( to extract the number of cases reporting severe side effects and the number of cases
with fatal side effects.

Result: The NNTV is between 200–700 to prevent one case of COVID-19 for the mRNA vaccine marketed by Pfizer, while the NNTV to prevent one death is between 9000 and 50,000 (95% confidence interval), with 16,000 as a point estimate. The number of cases experiencing adverse reactions has been reported to be 700 per 100,000 vaccinations. Currently, we see 16 serious side effects per 100,000 vaccinations, and the number of fatal side effects is at 4.11/100,000 vaccinations. For three deaths prevented by vaccination we have to accept two inflicted by vaccination.

Conclusions: This lack of clear benefit should cause governments to rethink their vaccination policy.

I hesitate to comment because some could think that I have a personal grudge, as Walach propagated lies about me. And crucially, like he, I am not a vaccination expert. Yet, I feel I ought to point out that the data that form the basis of Walach’s calculations should not be used in this way for at least two reasons.

  1. Death after vaccination does not mean that this event was caused by the vaccine. For example, if someone had a fatal accident after vaccination, it would count as a vaccine incident according to Walach’s calculation.
  2. Vaccine effectiveness cannot be measured by calculating how many people must receive a vaccine to prevent one case of COVID-19 vaccination. Since vaccines have a protective effect on the community, this would be an outright miscalculation. The more people who receive a vaccine, the fewer people need to receive it to prevent a single case. This situation is the exact opposite of what Walach assumes in his paper.

Conclusion: amongst all his previous nonsense, Walach’s new publication stands out, I feel, as the most stupid and the most dangerous. The mistakes seem too obvious to not be deliberate. Let’s hope the journal editor in chief (who failed miserably when publishing this idiocy) has the wisdom to retract it swiftly. One of its editors already tweeted:

I have resigned from the Editorial Board of

following the publication of this article. It is grossly negligent and I can’t believe it passed peer-review. I hope it will be retracted.

And another ed-board member had this to say:

14 Responses to COVID-19 vaccinations: Prof Walach wants to “dampen the enthusiasm by sober facts”

  • The other point that he seems to have missed is that the number you need to vaccinate to prevent one death depends on the prevalence of the disease in a population and also on the vulnerability of that population. The former is going to change as the pandemic evolves and is strongly influenced by how many are vaccinated already, and the latter depends on the age structure of the population concerned as well as any other risk factors. The reproduction number of the disease (R0, or the baseline average number of new cases each case generates) is also important; for the original variant, which was presumably the main one in the Israeli study, this was somewhere between 2 and 3, whereas for the delta variant (which is much more infectious) it is about eight.

    The proportion of the population who need to be immune in order to contain the pandemic is the reciprocal of R0, so it is now about 80%. Of course you need to vaccinate more than that as the vaccine does not give 100% immunity. If the vaccines had been widely available at the start of the pandemic and could have been distributed to everybody, we would only have needed to vaccinate about 60% to achieve the same degree of protection. It is a sobering thought that the transmissability of the virus has a much greater impact on the number of deaths than the case fatality rate, as common sense suggests that it should be the other way round. But that’s maths for you, and for an example look no further than SARS, which was highly virulent, killing about 1 in 7 people who caught it, but much less easily transmitted (and also not infectious until symptoms appeared) so there were only 774 deaths in total.

    I despair of statistics being bandied about by people who don’t understand them.

    A few weeks ago I was canvassed by a candidate for my local council elections. I asked him “what is 60% of 40?” and he couldn’t answer (if he had got it right I had a second question ready about calculating VAT). He was a nice chap and was duly elected. But how is he going to do his job effectively if he is mathematically illterate?

    • @Dr Julian Money-Kyrle
      About Walach’s number of 200-700 needed to vaccinate to prevent one infection: doesn’t this suggest that without vaccination, only 1 in every 200 to 700 people would contract Covid-19 to begin with? Or, at the other extreme, with full vaccination coverage, it would suggest that the vaccine is less than 0.5% effective in preventing infections. Both of which are of course utterly untrue.
      I can’t find any good information on a priori susceptibility to Covid-19 in an immunologically naive population, but given that e.g. here in the Netherlands, at least 12% of the population has contracted the infection before the start of vaccinations (and with numbers still rising at that point), this susceptibility must be at least 15%. Which, for a 90% effective vaccine would mean that in the beginning of the pandemic, I’d say the NNTV to prevent one infection is 7 at most, and probably even lower.

      It is indeed infuriating that Walach’s work of fiction is presented as ‘science’.

  • How does a “vaccine” that doesnt prevent catching the disease, such as the Covid19 ones, protect the community in the way that you imply? In the short term they only promise to reduce the severity of symptoms for those that do catch the disease. We have no idea about the long term effects of these experimental biological treatments. They also seem to cause shedding of particles (not viruses) that seem to affect the health of those who come in contact.

    • How does a “vaccine” that doesnt prevent catching the disease, such as the Covid19 ones, protect the community in the way that you imply? In the short term they only promise to reduce the severity of symptoms for those that do catch the disease.

      I think you are a bit out of date with the research. The end points of the initial trials were death and serious disease, rather than infection. However, it is pretty well-established now that they prevent transmission of the coronavirus, too.

      We have no idea about the long term effects of these experimental biological treatments.

      While we have not seen the long-term effects of these vaccines, which have after all only been introduced this year, the same is true of a great many interventions and activities. But it is wrong to say that we have no idea, as the mechanism of action and the immune response elicited are well-understood.

      We certainly don’t know what the long-term effect of covid is going to be, though an appreciable portion of people getting the disease seem to have lasting sequelae, aside from lung and kidney damage occurring in those with severe infections.

      They also seem to cause shedding of particles (not viruses) that seem to affect the health of those who come in contact.

      That’s a new one on me. Do you have any evidence for that claim. And could you suggest a biologically plausible mechanism whereby it could happen?

  • Irritating: Almost 300,000 full text views after 5 days

    • The corona deniers and vaccination opponents are well connected via social media. They will have quickly shared the new “proof” of the “danger” of vaccines/vaccination programs among themselves. However, I also think that numerous debunkers and fact checkers will have read through the “study” in order to uncover Walach’s falsehoods and misinformation and then to refute them.

  • What most stood out for me from this paper is the complete implausibility of the conclusions based on existing information about COVID. The death rate is *about* 1% for COVID, so that’s 10,000 deaths per million infected. The most serious adverse event is blood clots at *about* 8 events per million, and it is not necessarily fatal. I know these are just ballpark estimates, but it’s clear that the vaccine is several orders of magnitude safer than the disease, so to come out at a 3 COVID deaths prevented for 2 vaccine deaths just seems plain wrong.

  • “’Everything is to be thrown in this study, I do not understand how such nonsense can be published in a scientific journal which is supposed to have its articles revised’, reacted Professor Mathieu Molimard, head of the pharmacovigilance service at the Bordeaux University Hospital.”


  • The journal [Vaccines] retracts the article, The Safety of COVID-19 Vaccinations—We Should Rethink the Policy

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