“VAIDS” is not a real medical condition; causes of post-vaccination syndrome require more research

A Facebook reel shared on 22 February 2025 claimed that COVID-19 mRNA vaccines cause “vaccine-acquired immunodeficiency syndrome” (VAIDS). The reel cited a study from Yale researchers that allegedly found these vaccines alter human biology, and more specifically that they “alter T-cell immunophenotypes, which triggers VAIDS”.

The reel was posted by political commentator Liz Wheeler, whose account has more than 1.4 million followers. At the time of publication, the reel had been viewed more than 630,000 times. Wheeler has a track record of spreading false information about COVID-19 and vaccines, as shown by previous reviews from Science Feedback and FactCheck.org.

Other posts on Facebook, Instagram, and TikTok (examples here, here, and here) also cited the Yale study, but instead highlighted a different condition called “post-vaccination syndrome” (PVS). These posts claimed that researchers found PVS may be caused by the spike protein in COVID-19 mRNA vaccines.

These social media posts misrepresent the study’s findings, blaming COVID-19 vaccines as the culprit that causes PVS and VAIDS. In reality, the study aimed to better understand the biological mechanisms that cause PVS, but remained exploratory in nature and didn’t provide evidence demonstrating a causal relationship between COVID-19 mRNA vaccines and PVS. Furthermore, the study didn’t address VAIDS at all, which is not a real medical condition. We explain more below.

Post-vaccination syndrome is rare; its causes are still unknown

The term “post-vaccination syndrome” (PVS) refers to a label given to those who develop chronic symptoms like excessive fatigue, brain fog, insomnia, and dizziness soon after receiving a COVID-19 vaccine. Cardiologist Harlan Krumholz, who has contributed to research on the potential causes of PVS, explained how the condition was given its name in an interview with FactCheck.org in December 2023:

“[W]e are describing the experience of people who have a chronic syndrome that begins soon after the COVID-19 vaccination. Since we do not know the cause, we labeled it a post-vaccination syndrome. We described it like that because that’s the timing of it.” 

The “Yale study” on PVS cited by social media posts likely refers to a preprint published in February 2025 by Bhattacharjee et al. that explored the potential biological mechanisms that cause PVS. The preprint shared findings from a small study of 64 people that examined differences in immune profiles between people with and without PVS. Among the findings were that participants with PVS had “higher levels of circulating spike protein compared to healthy controls”, which some social media users took to mean that PVS is caused by spike protein from COVID-19 mRNA vaccines.

However, it’s not yet possible to draw this conclusion from this research for a few reasons.

First, this study is still a preprint, which means that its findings haven’t yet been peer-reviewed. It may therefore contain errors, biases, or unsupported claims that haven’t been rigorously vetted by experts. In an interview with the New York Times originally published on 19 February 2025, Akiko Iwasaki, an immunologist and co-author of the preprint, also shared that the authors’ findings didn’t “[determine] what’s making people sick, but it’s the first kind of glimpse at what may be going on within [people with PVS].”

Second, the study was limited in its design. It relied on self-reported data from its participants, which can be prone to bias, since people may have difficulty accurately recalling past events or may unintentionally underreport or exaggerate health information. Its small sample size also renders it difficult to demonstrate that the association between PVS and the presence of elevated spike protein levels is causal in nature.

In short, the preprint was a preliminary look into the potential biological underpinnings of PVS. More research is needed to better understand what causes this condition.

Vaccine-induced AIDS (VAIDS) is not a real condition

For context, VAIDS, or “Vaccine-Induced AIDS”, is not a medically recognized disease. It’s a term that has been used to spread misinformation about COVID-19 vaccines, primarily suggesting that they cause immune system damage similar to acquired immunodeficiency syndrome (AIDS), a disease caused by the human immunodeficiency virus (HIV).

But the preprint cited as evidence for the association between COVID-19 mRNA vaccines and VAIDS made no mention of this so-called medical condition. It strictly analyzed the pathobiological features of PVS in an attempt to “better understand this condition and inform future research into diagnostic and therapeutic approaches”.

What’s more, COVID-19 mRNA vaccines don’t alter or harm the immune system in the way that HIV does. HIV and AIDS attack and weaken the immune system by targeting key immune cells, leaving the body vulnerable to infections and diseases. In contrast, COVID-19 vaccines are designed to stimulate the immune system to recognize and fight the virus without altering or damaging the immune system’s overall function. These vaccines help to protect the body against COVID-19 without compromising immune health.

Finally, it’s worth noting that if COVID-19 vaccines caused an immunodeficiency virus like AIDS, vaccinated people would be more susceptible to opportunistic infections (OIs) caused by viruses, bacteria, fungi, and parasites. People with weakened immune systems are more susceptible to OIs because it’s harder for their bodies to fight off infections, and these infections can lead to severe consequences, including death. In short, at this point in time, we would have observed a far greater number of deaths among vaccinated people if vaccines did indeed cause immunodeficiency viruses.

Conclusion

The social media claims linking COVID-19 mRNA vaccines to “vaccine-acquired immunodeficiency syndrome” (VAIDS) and “post-vaccination syndrome” (PVS) misrepresent the findings of a recent preprint from Yale researchers. The study in question did not address VAIDS, a non-existent condition, nor did it definitively establish that the spike protein causes PVS. The research was preliminary, based on a small sample size and self-reported data, and its conclusions have yet to be peer-reviewed. As such, more rigorous research is needed to understand PVS, and claims linking the vaccines to immune system damage are unfounded and misleading.