Elon Musk this week amplified an unfounded claim, based on a distortion of vaccine safety monitoring data, that COVID-19 vaccines killed tens of thousands of people in Germany. The vaccines saved millions of lives worldwide during a deadly pandemic, and serious side effects or deaths from vaccination are rare.
Despite this well-established safety record, Musk questioned COVID-19 vaccine safety on X on April 12 while sharing a post from far-right Swedish influencer Peter Imanuelsen, who also goes by PeterSweden. Musk, a former Trump adviser who is CEO of SpaceX and Tesla and owns X, has previously amplified and interacted with Imanuelsen’s posts on multiple occasions. Musk’s post had nearly 60 million views as of this story’s publication, and Imanuelsen’s had 64 million.
“A Pfizer insider who was former head of toxicology in Europe has just come out and said something that many ‘conspiracy theorists’ suspected,” Imanuelsen wrote in his April 12 post. “He estimates that 20 000 to 60 000 people in Germany have died from the c*vid vaccine,” he continued, adding that it “should be headline news EVERYWHERE.”
There is no evidence this large number of deaths occurred. Nor did COVID-19 vaccines cause mass deaths in general, as we have written multiple times.
Imanuelsen’s post was based on March 19 testimony at a German parliamentary hearing from Dr. Helmut Sterz, a toxicologist and veterinarian who reported formerly working for Pfizer. Sterz, who appeared at the invitation of a far-right party, baselessly claimed that the Pfizer/BioNTech vaccine killed 60,000 people in Germany. But Sterz arrived at this number by distorting German vaccine safety monitoring data, following logic also common to anti-vaccine activists in the U.S. who have misused similar passive surveillance data. (Imanuelsen explained on X that Sterz had also given the 20,000 figure after the hearing, but we were unable to locate these further comments.)
Dr. Mahmoud Zureik, a professor of epidemiology and public health at University of Paris-Saclay in France, told us via email that Sterz’s claim “confuses coincidence with causation, misuses passive surveillance data, and is not supported by the best available scientific evidence.” Sterz counted deaths reported after vaccination that were not necessarily related to the vaccines and then multiplied them by 30 to purportedly account for underreporting. Zureik called the use of this factor of 30 “arbitrary.” Zureik is director of EPI-PHARE, a scientific organization created by French health authorities to independently advise on health product safety.
Zureik added that the idea that COVID-19 vaccines have caused large numbers of deaths is inconsistent with the scientific literature. “More broadly, large epidemiologic studies have not shown an excess risk of overall mortality after COVID-19 mRNA vaccination,” he said.
Pfizer spokesperson Andrew Widger told us via email that the company’s COVID-19 vaccine “continues to demonstrate a favourable safety and efficacy profile supported by extensive real-world evidence as well as by clinical, non-clinical, pharmacovigilance, and manufacturing data.“
A LinkedIn profile lists Sterz as having held a leadership role at a Pfizer research center in France from 2001 to 2009. He is author of a 2025 book about COVID-19 whose title translates to “The Vaccination Mafia,” and whose subheading describes him as Pfizer’s former chief toxicologist. He does not appear to have any recent scientific publications.
Pfizer as a policy doesn’t “provide details regarding individuals,” the company’s spokesperson said, “but I can confirm the individual you mention was not working at Pfizer during the pandemic or during the decade preceding it, and consequently had no involvement in the development of the COVID-19 vaccine. I would question therefore whether he could be described as an ‘insider.’”
Misuse of German Vaccine Safety Surveillance Data
In the U.S., anti-vaccine activists often distort data from the government-run Vaccine Adverse Event Reporting System, or VAERS, which collects unverified reports of health problems following vaccination in order to identify possible safety signals. Sterz’s unfounded claim about vaccine deaths in Germany relies on misuse of a similar government system in Germany, run by the Paul Ehrlich Institute, which we have also written about before.
During his testimony, Sterz said that PEI had gotten 2,133 reports of death after vaccination with Pfizer/BioNTech’s vaccine. There were indeed 2,133 reports of deaths following vaccination with the original Pfizer/BioNTech vaccine through the end of 2024, according to a 2024 PEI report.
However, Zureik said that a death or other problem happening after vaccination “is not, by itself, evidence that the vaccine caused the event,” explaining that systems such as the PEI one “are designed to detect signals that then necessarily require clinical and epidemiological assessment.”
“It is not valid to presume the 2000 reported deaths were caused by vaccines, much less to presume that there were 30x this number to arrive at the 60k number the person claims,” Jeffrey S. Morris, director of the division of biostatistics at the University of Pennsylvania’s Perelman School of Medicine, told us via email. Morris wrote a December 2025 Annenberg Public Policy Center white paper on vaccine safety monitoring, including a section explaining how VAERS functions and is distorted. (FactCheck.org is a project of APPC.)
People die on a regular basis, including 1 million per year in Germany, Morris and Zureik both noted. “Therefore, when tens of millions of people are vaccinated, some deaths will inevitably occur in the days, weeks or months following vaccination purely by coincidence, including deaths that would also have occurred in the absence of vaccination,” Zureik said.
The PEI report also said that the occurrence of deaths or other events near the time of vaccination “does not automatically indicate that there is a causal relationship” between the two, explaining that in many cases, “the event can be explained by other factors, such as pre-existing conditions, comorbidities, or concomitant medications.” In other cases, there is limited information available. Of the 2,133 reports of deaths after receiving the original Pfizer/BioNTech vaccine, PEI assessed 28 as having a “possible or probable” causal relationship with vaccination. The report said more than 138 million doses of the vaccine had been given.
Unsupported Use of ‘Underreporting Factor‘
Sterz again followed a familiar pattern in multiplying an already-inflated number of deaths alleged to have been caused by COVID-19 vaccination by an “underreporting factor” of 30, which he said was used in the U.S.
American anti-vaccine advocates indeed multiply purported vaccine deaths or vaccine side effects by various factors, with Dr. Peter McCullough, for instance, often mentioning an underreporting factor of 30. McCullough is a cardiologist with a long history of spreading incorrect information about vaccines.
But as we have written before, the approach of applying an underreporting factor to reports from VAERS to identify the “true” rate of a problem is flawed. There is both underreporting and overreporting of events, and it’s not straightforward to identify a specific underreporting rate, which will vary depending on what events someone is looking at and the context in which a vaccine was given.
During the COVID-19 pandemic, Zureik explained, it’s possible that there was in fact “overreporting driven by what is known as notoriety bias (or stimulated reporting).” In other words, the widespread attention to COVID-19 vaccination and possible side effects may have led people to be more likely to report deaths that happened near the time of vaccination, regardless of any causal relationship.
“Therefore, applying a fixed ‘underreporting factor’ is not only unsupported but also ignores the possibility of reporting inflation in this context,” Zureik said.
Reassuring Data on COVID-19 Vaccine Safety
Regardless, there are other types of studies used to further investigate any safety signals found by surveillance systems like VAERS or the PEI system, Morris said. These sorts of studies looked at deaths after COVID-19 vaccination and have shown “no evidence of increased risk of death,” he said.
In the U.S., a 2022 study of nearly 7 million people from the Vaccine Safety Datalink monitoring system found that people who received COVID-19 vaccines were less likely to die than those who did not get the vaccines, after matching people by various characteristics and following them over at least two months. VSD is a U.S. health care record-based system that can be used to follow up on safety signals identified in VAERS. “This is far stronger evidence than any VAERs analysis,” Morris said.
Zureik and his colleagues in France, meanwhile, looked at French health records from 28 million adults age 59 and under to investigate whether COVID-19 vaccination had any association with death from all causes over a four-year period. Their study, published in December 2025, again found that vaccinated people were less likely to die than those who were unvaccinated.
Morris explained that these studies and others from around the world don’t necessarily mean that vaccination decreases risk of death from causes other than COVID-19, since people who get vaccinated may have other characteristics that make them healthier. However, the research indicates that COVID-19 vaccines are not associated with any increased risk of dying, contrary to claims about large-scale lethality.
People have expressed particular concern about spikes in sudden deaths caused by vaccination, despite a lack of evidence for such a phenomenon. This is partly based on the real but rare side effect of myocarditis, or inflammation of the heart. Some COVID-19 vaccines, including the Pfizer/BioNTech vaccine, caused this condition, which most often affected adolescent or young adult males after the second dose of the original series. Myocarditis after COVID-19 vaccination is generally less severe than after infection and resolves relatively quickly, although it is possible that it has caused deaths in some very small number of cases, as we’ve written previously.
But again, studies do not show a pattern of increased deaths in adolescents and young adults after vaccination, either from heart-related or other causes. Most recently, a March 19 Canadian study investigated whether COVID-19 vaccination in adolescents and young adults without documented heart disease was associated with sudden cardiac death, which can be caused by various conditions, including myocarditis.
The researchers found that vaccinated people were less likely to have sudden cardiac deaths than unvaccinated people. “These findings do not support the hypothesis that COVID-19 vaccines increase the risk of sudden cardiac death in young healthy adults,” the authors concluded.
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