The tweet claims that most childhood vaccine trials use other vaccines as controls, which are immunologically active and not inert placebos. In reality, saline-placebo-controlled trials are conducted for many vaccines to assess both safety and efficacy:

• Rubella vaccine
• Pneumococcal vaccine
• Hib vaccines
• HPV vaccine
• The Salk Polio vaccine
• Measles vaccine
• Tdap vaccine
• COVID vaccine

It is true that sometimes a new vaccine is tested against an existing vaccine, or a placebo may contain an adjuvant, buffers, or stabilizers with a known safety record.

The World Health Organization guides the ethical use of placebos in vaccine trials in certain situations. It is acceptable when no effective vaccine is available and the new vaccine is intended to benefit the population being studied.

However, using placebos is considered unacceptable when there is already an effective and safe vaccine accessible in the public health system of the country where the trial is planned. In such cases, it would be unethical to withhold the existing vaccine from participants if not receiving it would pose a significant risk to their health.

The tweet cites examples like Prevnar-13 and Gardasil, suggesting that their safety profiles were not adequately assessed because the control groups received other vaccines or adjuvants. Prevnar-13 was licensed based on a trial comparing it to Prevnar-7, which was already effective in preventing certain diseases caused by pneumococci.

It would have been unethical to use a saline placebo for Prevnar-13 when a vaccine was already available that provided significant protection against severe bacterial infection. Purposely leaving children at risk, without their knowledge, when an approved vaccine with a known safety record was available would have meant purposely allowing children to get sick and worse.

Furthermore, the CDC’s definition of placebo is consistent with the accepted scientific understanding of placebos in vaccine trials. Inert placebos, such as saline solution, are commonly used, but in some cases, an active control, such as another vaccine, may be used to protect the health of participants.

It may be difficult to convince an ardently anti-vaccine person of the value of non-saline placebos because they enter the conversation already believing that vaccines writ large are dangerous.

In a Netflix special, comedian Joe Rogan expresses a dramatic shift in his beliefs and trust in information due to the experiences and events surrounding COVID. Where he once had a strong faith in vaccines and mainstream historical events, after the pandemic, he became highly skeptical and started to believe in various conspiracy theories, using hyperbolic examples like doubting the moon landing and believing in Pizzagate to highlight this newfound skepticism.

Hyperbole or not, this is an excellent example of the correlation between believing in COVID conspiracies and an increase in general conspiratorial beliefs. Studies show that belief in one conspiracy theory often leads to belief in others.

Because many conspiracy theories share similar underlying themes, such as distrust in authorities or the idea of hidden, powerful groups controlling events, once someone accepts one conspiracy theory, they become more receptive to others that fit within this worldview. They become trapped in a self-reinforcing cycle of conspiratorial thinking.

But why did Joe Rogan and others become skeptical of vaccines in the first place when vaccines have a proven track record of eradicating or controlling diseases like smallpox, polio, and measles, significantly reducing morbidity and mortality worldwide?

The COVID vaccines underwent rigorous testing in large-scale clinical trials involving tens of thousands of participants to ensure their safety and efficacy, and multiple studies have shown that vaccines reduce the severity of the disease, lower the risk of hospitalization, and decrease mortality rates. Yet many think they’re the cause of countless deaths and disabilities.

A video claims that some people died within a few hours or even minutes after receiving a COVID-19 vaccine, suggesting that these deaths were caused by the vaccine, with one highlighted case of an 88-year-old man who allegedly died within seconds of vaccination.

The basis of these claims comes from laypeople searching through the Vaccine Adverse Event Reporting System, or VAERS. Anyone can report anything to VAERS, regardless of causation, as is noted on the VAERS website.

One doctor famously submitted a report that the flu shot turned him into the Incredible Hulk. VAERS is helpful for keeping track of vaccine safety, but just because something is reported doesn’t mean the vaccine caused it. Even if they’re not sure, doctors should report any important health problems that happen after vaccination.

The most pertinent warning on the website helps put the above claims into context: “VAERS reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable. Reports to VAERS can also be biased. As a result, there are limitations on how the data can be used scientifically. Data from VAERS reports should always be interpreted with these limitations in mind.”

These “sudden death” claims by anti-vaxxers usually don’t have any proof to back them up. They, and we, do not have access to medical records or other information to pinpoint the causes of these deaths.