Sorry Virus Deniers: Failing to Grow Cells Isn’t Science and It Doesn’t Disprove the Existence of Viruses

No matter how many times you try it.

TL;DR: Virus deniers continue to cast doubt on cytopathic effects (CPE) as their single refutation to virology with their own set of experiments, but they cannot demonstrate or explain dilution of CPE. This simple fact completely invalidates their entire unscientific approach, even when you disregard mountains of proteomic, genomics, and molecular data.

Things you won’t see in a Virus Denier “Experiment” #1": Dilution of the Cytopathic Effect

(Taştan et al., 2020, Turkish Journal of Biology)

Serial passage and dilution of the CPE is something you will not find in Virus Denier “Experiments” and cannot be explained. In this paper isolating SARS-CoV-2 from Turkish patients, researchers performed serial dilutions of patient swab samples on Vero and MDBK cells to test infectivity. What they observed was classic virology: at higher concentrations of viral inoculum, widespread cytopathic effects appeared including plaques, cell rounding, and detachment of the monolayer. As the inoculum was diluted, the cytopathic effect diminished proportionally, with fewer plaques and less cell death. At very low dilutions, only rare CPE was visible, and in uninoculated negative controls there was none at all. This “dilution of effect” is the hallmark of a transmissible infectious particle because the damage is directly tied to viral dose and propagation. Starvation-induced stress, as performed in Virus Denier “control experiments,” cannot produce this pattern as stress affects all cells in the culture equally, regardless of dilution, and does not replicate or spread. The Turkish study therefore demonstrates the essential feature of viral infection: cytopathic effect tracks with viral input, dilutes predictably, and confirms the presence of infectious SARS-CoV-2 particles.

Who Are Virus Deniers?

Virus deniers are a small group of people who reject the overwhelming evidence that viruses exist and cause disease. They rarely are scientists by training or practice. Instead, they share the same mistrust of science seen in flat-earth circles or anti-vaccine movements.

The latest claim making the rounds on Substack argues that virus isolation protocols are invalid because lowering serum in cell culture causes cell stress, and stressed cells can sometimes look like infected ones. From this narrow observation they built an entire strawman to leap to the extraordinary conclusion that virology itself is a fraud.

Why is this wrong? Virology doesn’t just study human pathogens; it includes viruses that infect bacteria, archaea, protists, plants, fungi, and even brown algae. To believe the denialist narrative, we would have to assume every biologist in every field is engaged in a pointless lie, with no monetary incentive.

The Conspiracy Playbook

As with other conspiracy groups, virus deniers follow the same tired playbook for making their pseudo-experiments:

• Start with the conclusion: declare from the outset that viruses don’t exist.

• Cherry-pick observations: point to serum starvation or osmotic stress as if cell stress explains everything.

• Ignore broader evidence: dismiss genomics, protein biochemistry, structural biology, and infection assays.

• Ignore counter-evidence: overlook that CPE dilutes only when infectious virus is present, not when media is altered.

• Claim a cover-up: insist virologists worldwide have been “lying” for more than a century.

• Stage a publication: bypass peer review and post “results” on a personal blog or Substack. The more sophisticated deception is to post on non-peer review archives, such as Zenodo

Why Virus Denier “Experiments” Fail to Test Anything

The inception of the Virus Denier Cell Culture “Experiment”, which they like to call the “Control Experiment” can be traced back to one of the most prominent figures in the movement, Stefan Lanka.

Lanka is a former German biologist who became infamous in the 1990s for denying the existence of HIV. Over time he expanded his claims and ultimately asserted that no viruses exist at all. According to him, what mainstream science identifies as viruses are merely laboratory artifacts or misinterpretations of normal cellular stress. Ironically, Lanka himself has only five unremarkable scientific publications from his early career, and every one of them demonstrates the existence of viruses, particularly Ectocarpus siliculosus virus, a double-stranded DNA virus of brown algae.

In 2015, Lanka attracted media attention after offering €100,000 to anyone who could prove the existence of the measles virus. A young doctor, David Bardens, submitted extensive scientific evidence, including six peer-reviewed publications. A German court initially ruled that Bardens had proven the case, but a higher court later overturned the ruling on a technicality (that the evidence had not been presented in a single publication). Importantly, the judgment did not dispute the existence of measles virus (clause 104), only the terms of the bet that all the information Lanka request be in a single publication (clause 122). Nonetheless, Lanka used the case to promote his denialist agenda and Virus Deniers still falsely claim that the courts came to this conclusion based on evidence. However, casting doubt on experiments aren’t enough to convince most people there is a massive conspiracy afoot, so Lanka needed to cook up another way to propagate his denial.

Lanka’s so-called “control experiment” became the template for much of the current virus denial movement. His claim was if you grow cells under stressful conditions, such as reducing fetal bovine serum or in the presence of an osmotic stress in culture, they undergo morphological changes and may die. He insisted these changes mimic the cytopathic effects (CPE) seen when cells are infected by viruses. From this, he concluded that all virology is invalid, because scientists have supposedly mistaken cell stress for viral infection.

One would think that a scientist, even with as limited a publication record as Lanka’s, would seize the opportunity to overturn all of virology as Lanka so proudly proclaimed his results would. Yet his findings never appeared in the pages of Science or Nature or any reputable scientific journal. In fact, they cannot even be found on his own website, WissenshaftPlus. What you can find is a PDF that circulated briefly on Telegram, after Lanka scrubbed it from his site.

Why? Deep down, Lanka must have realized that starving cells or allowing them to overgrow in culture to mimic CPE-like changes was not enough. Without solid molecular evidence, genomes, proteins, or any reproducible markers, his “experiment” had nothing to offer.

Stefan Lanka: “And as soon as I get hold of original sequence data which was produced for HIV, I am going to produce you [the] coronavirus. Definitely! And this is going to be the definitively experimental disproval of virology.” Lanka disappeared from the public after making this statement. (Taken from Visser, 2021: Integral World)

Things you won’t see in a Virus Denier “Experiment” #2: Genomic Alignment

One of the cornerstones of modern biology is genomic alignment. When a virus is isolated, its genome can be sequenced and then compared to thousands of other viral genomes across the world. This is how we know SARS-CoV-2 has over 14 million publicly available sequences that line up nearly base for base, with predictable mutation patterns that match transmission chains and evolutionary history. Alignment demonstrates that we are not dealing with random noise or “artifacts,” but with structured genomes that encode functional proteins. Virus denier “experiments” never produce this evidence. They stop at looking through microscopes, pointing at stressed cells, and declaring “CPE is fake.” But without genomic data or molecular data of any sort, there is no way to show that what they are looking at has identity, structure, or evolutionary coherence. They avoid sequencing because alignment would immediately reveal that their stressed cell cultures contain nothing resembling a viral genome, let alone one that matches the millions of sequences independently obtained worldwide.

Virus deniers have falsely cast doubt on genomic data by fixating on minor misalignments or on the fact that different assembly programs can vary in their success. For example, when the original metagenomic data from one of the first COVID-19 patients in China was analyzed, they quickly criticized that MEGAHIT produced a full-length SARS-CoV-2 genome in one piece while another assembler did not. They claimed this meant assemblers “randomly paste sequences together” and that scientists simply “chose the longest one.” This is wrong. Metagenomic assembly deals with mRNA from many organisms in a sample, and non-viral genomes do not align to the SARS-CoV-2 sequence. The longest contiguous assembly is not arbitrary and it is supported by consistent overlaps and confirmed by downstream validation. Virus deniers also point to the fact that genome ends are sometimes incomplete, ignoring that terminal regions naturally degrade first, are more repetitive, and are harder to assemble. It is the equivalent of a completed puzzle missing a few corner pieces: the picture remains perfectly clear and recognizable.

Lanka’s “Control Experiment” Deception

While it was never submitted to a peer-reviewed journal, Stefan Lanka promoted his so-called “control experiment” as the final refutation of virology. His project was announced in three phases: (1) claiming that cytopathic effects (CPE) can be produced without viruses, (2) alleging that the SARS-CoV-2 genome was artificially constructed, and (3) suggesting that any viral genome could be assembled from random human or animal RNA. None of these claims were published in scientific journals; instead, fragments of the work appeared anonymously on Telegra.ph, and were later scrubbed from Lanka’s own website. Control Experiment (2) and (3) never materialized. Instead, Lanka bizarrely had an unnamed mathematician analyze the original SARS-CoV-2 genome paper.

Lanka’s central rhetorical move was to confuse non-experts into thinking he had produced genomic data. He misrepresented the original SARS-CoV-2 genome paper by arguing that Chinese scientists “invented” the genome by designing interspaced primers to fill in gaps they wanted, rather than simply developing primers to confirm the metagenomic assembly through amplicon sequencing. This distortion made it sound as if the genome was fabricated by choice, when in fact the process followed standard scientific practice.

Frank Visser, who carefully examined Lanka’s claims, pointed out that the “control experiment” was never actually performed and that Lanka lacked both the expertise and the laboratory capacity to carry it out. Visser explained that Lanka’s argument rests on a shallow analogy: since any book can be written with the same alphabet, viral genomes must therefore be arbitrary. In reality, genomes emerge directly from overlapping sequence reads, much like sentences quickly reveal which book you are reading. Visser also noted that even when Lanka’s supporters attempted genome assemblies, they reconstructed nearly the entire SARS-CoV-2 genome with high-quality alignment from the SARS-CoV-2 sample data, directly contradicting the claim that genomes are arbitrary. Virus deniers, by contrast, have never been able to assemble a SARS-CoV-2 genome, or any other viral genome, from their own experiments or from unrelated sequence sets on NCBI that have nothing to do with viruses.

Lanka never produced empirical genomic evidence. His so-called “control experiment” amounted to little more than cell stress artifacts and a misrepresentation of how sequencing works. Genomes are not fabricated out of thin air; they arise from real biological data. Lanka’s complete failure to produce any genome evidence is proof that his claims collapse under scrutiny (Visser, 2021: Integral World).

A clear explanation of these issues can also be found in Dr. Dan Wilson’s video, Debunk the Funk: Stefan Lanka’s “Control Experiment” and Virus Denial (watch here). Wilson walks through the flaws in Lanka’s claims step by step, showing why cell stress is not equivalent to viral infection and why the genomic evidence is undeniable.

Deception Beyond Lanka

In recent years, the virus denier community has shrunk to a small, fractured group plagued by infighting. Much of its brief surge in popularity came during the COVID-19 pandemic, when lockdowns and vaccine mandates created fertile ground for conspiracies. Post-pandemic, the audience has dwindled, with only a few dedicated individuals still promoting the so-called “control experiment.”

The most recent iteration comes from Jamie Andrews, a self-proclaimed sovereign citizen with no scientific training. Building directly on Lanka’s framework, Andrews argues that cytopathic effects (CPE) are caused not by viral replication but by the reduction of fetal bovine serum (FBS) in culture media. FBS provides nutrients and growth factors that stimulate cell division. When its concentration is lowered for extended periods, cells enter arrest and show morphological stress. Ironically, in proper viral studies, temporary FBS reduction can make some cell types more permissive to viral infection, not less.

Andrews’ group first used HEK293T cells and recent iterations used Vero cells. They reported that under low-FBS conditions, cells exhibited changes such as rounding, lifting, syncytia, and plaques morphologies that superficially resemble viral CPE. They went further, sending samples to a contract lab for Transmission Electron Microscopy (TEM). The report claimed to see “viral-like particles” resembling SARS-CoV-2, measles virus, and HIV. But no molecular work was done: no sequencing, no protein assays, no reinfection studies. What was presented as “viruses” were almost certainly extracellular vesicles and cell debris, which are well-known to resemble viral particles under TEM.

Why HEK293T Cells Are a Bad Choice

Jamie’s “control experiments” rely heavily on HEK293T cells, but this is an inappropriate model for the claims he is trying to make. When challenged, Jamie cited a protocol that actually used HEK293 cells, not HEK293T. The distinction is critical. HEK293T cells, unlike HEK293, are highly sensitive to nutrient deprivation and quickly arrest in the G1 phase of the cell cycle when grown in low fetal bovine serum (FBS). Arresting cells in G1 for more than 24 hours is damaging, since HEK293T cells lack normal transcriptional activation pathways to cope with stress. This is why researchers do not maintain HEK293T cultures in prolonged low-FBS conditions—they simply are not stable in that environment.

By keeping HEK293T cells in low FBS for 3–4 days, Jamie virtually guaranteed stress-induced morphological changes, independent of any viral infection. In other words, his “experiment” was designed to fail from the start. What he interpreted as evidence against virology was simply the predictable result of starving a fragile, immortalized cell line.

Ironically, the very cells Jamie relies on to “prove” viruses don’t exist are themselves a product of viruses. HEK293T cells were created by infecting human embryonic kidney cells with adenovirus DNA, which immortalized them, and later modified with the SV40 large T antigen, a viral protein from Simian Virus 40. These viral elements are what allow HEK293T cells to replicate indefinitely and to be so useful in biotechnology. In other words, without viruses, HEK293T cells wouldn’t even exist. Virus deniers are literally using a virus-engineered tool to argue that viruses aren’t real.

Things you won’t see in a Virus Denier “Experiment” #3: A Virus Positive Control

Virus deniers like Jamie often argue that they can simply compare their results to published papers and therefore do not need to include a virus-positive control. This is a fatal flaw. Without a positive control, their experiments cannot conclude anything. If viruses truly did not exist, then a virus-positive control would look no different from their untreated controls. But in every published isolation study, the difference is obvious: infected cells show reproducible cytopathic effects, while uninfected controls remain healthy. For example, in the study Inactivation of Influenza A Virus, Adenovirus, and Cytomegalovirus with PAXgene Tissue Fixative and Formalin (Miranova et al., 2018), infected cells were imaged alongside uninfected controls to validate the inactivation process. The contrast is striking: viral CPE and structural particles are clearly observable in the positive control, whereas uninfected cells show none. This side-by-side evidence is exactly what virus denier “experiments” lack and why they cannot stand up to scientific scrutiny.

Things you won’t see in a Virus Denier “Experiment” #4: Correct Virus Morphology

Jamie has claimed that his TEM images revealed particles resembling HIV. But if that were true, where are the hallmark features of HIV virions, the roughly spherical particles ~100–120 nm in diameter, each containing two copies of single-stranded RNA, a conical core, and a lipid envelope studded with glycoproteins? Show me the particles that actually meet those criteria, as seen in every authenticated micrograph of HIV.

The reality is that most of Jamie’s so-called “virus-like particles” are just extracellular vesicles, apoptotic bodies, or cellular debris. They lack the structural consistency, genome packaging, and reproducibility that define real viruses. Morphology is not about vaguely round blobs under a microscope; it’s about highly specific, recognizable structures that trained virologists can distinguish. Virus deniers, lacking training and relying only on superficial resemblance, mislabel cellular trash as viruses. In science, details matter, and their particles don’t add up.

Things you won’t see in a Virus Denier “Experiment” #5: Immunogold labeling

Virus deniers love to cite Best Practices for Correctly Identifying Coronavirus by Transmission Electron Microscopy (Bullock, Goldsmith, & Miller, 2021, Kidney International) to argue that identifying viruses by TEM alone is unreliable. Ironically, they ignore the actual recommendations in that very paper. Bullock and colleagues explain that TEM must be paired with methods like immunogold labeling or ultrastructural in situ hybridization to conclusively demonstrate virus particles inside cells. Immunogold uses antibodies tagged with gold particles to bind specifically to viral proteins, showing that the structures seen under the microscope are not just random vesicles or organelles, but bona fide viruses.

This is exactly what virus deniers never do. Jamie, for example, points to blurry TEM images and claims they show HIV or SARS-CoV-2. But without immunogold labeling, those particles could just as easily be extracellular vesicles or normal subcellular structures. Proper virology doesn’t stop at “round blob = virus.” It requires structural identification, biochemical confirmation, and molecular alignment. The absence of immunogold labeling in denialist experiments is one of the clearest signs that they are not doing science, but staging optics.

Virus Deniers Are Not Just Ignorant, They Are a Danger

In the end, virus denial collapses under the weight of its own contradictions. Real virology demonstrates reproducible infection: cytopathic effects that dilute with viral dose, genomes that align across millions of sequences, proteins that function biochemically, and particles that reinfect in controlled assays. Virus denier “experiments” show only stressed cells and blurry images, with no molecular data, no positive controls, and no coherent explanation. Their work is not science but performance, designed to sow doubt rather than discover truth. The irony is that even the tools they use, like HEK293T cells, exist only because of viruses. The evidence for viruses is overwhelming, convergent, and undeniable; what the deniers offer is nothing more than noise.

Virus denial is not harmless eccentricity. Like flat-earth conspiracies, it is rooted in mistrust of institutions and science, but it carries far greater consequences. If viruses don’t exist, then HIV, measles, and COVID don’t exist either, and therefore there is no need to test, treat, or prevent them. This ideology can convince vulnerable people to reject lifesaving medicines or vaccines, leaving them and their communities at risk. Dismissing viruses as “fiction” does not erase them; it only erases the tools we have to fight them. That is why virus denial is not just ignorant, it is dangerous.