What an anti-vaxxer usually argues

“Vaccines aren’t tested with real (inert) placebos.” They’ll say trials often use an “active comparator” (another vaccine or an adjuvant like aluminum) rather than saline, so safety signals could be masked.
“There are no true double-blind trials.” They’ll argue blinding is broken (e.g., by reactogenicity) or that trials are “observer-blinded,” not fully double-blinded.
“Follow-up is too short and placebo groups are crossed over.” They’ll point out that once a vaccine shows benefit, placebo recipients are often offered the vaccine, which can limit longer-term comparison.
“Ethics is used as an excuse.” They’ll claim researchers hide behind ethics to avoid saline placebos even when a placebo would be possible.

What the science and ethics actually say

Many vaccines have, in fact, been tested in randomized, double-blind, placebo-controlled trials (saline or inert placebo), especially when no proven vaccine existed yet. Classic and recent examples include the 1954 Salk polio field trial (randomized, double-blind, saline placebo; ~1.8 million children), the rotavirus vaccines RotaTeq and Rotarix (large phase-3, double-blind, placebo-controlled programs), and the 2020–21 Pfizer-BioNTech COVID-19 phase-3 trials (randomized, placebo-controlled, observer-blinded). (McGill Medicine, Random Services, U.S. Food and Drug Administration, European Medicines Agency (EMA), New England Journal of Medicine)
When an effective vaccine already exists, using a saline placebo is usually unethical. Global ethics standards (e.g., the Declaration of Helsinki and WHO guidance) state that new interventions should be tested against the best proven intervention; placebo control is appropriate mainly when no effective vaccine exists (or in a few narrowly defined scenarios). That is why many later-generation vaccines are compared to an existing vaccine rather than saline. (WMA, PMC)
Active comparators (including adjuvant-only controls) are legitimate methods to isolate the effect of the antigen while keeping blinding intact; regulators have accepted them (e.g., HPV vaccine trials used adjuvant-only or prior-generation comparators, alongside saline in some studies). (U.S. Food and Drug Administration)
Blinding and trial rigor: Large vaccine RCTs are routinely double-blind or observer-blinded (a standard approach in vaccine trials to maintain objectivity), and they enroll tens of thousands of participants with prespecified safety and efficacy endpoints reviewed by independent boards and regulators. (New England Journal of Medicine)
After approval, safety is continuously monitored (e.g., VAERS, Vaccine Safety Datalink), which can detect very rare adverse events that pre-licensure trials are underpowered to find. (This is part of why vaccine safety is considered unusually well-studied.) (The Washington Post)

Concrete examples you can cite

Polio (Salk, 1954–55): Randomized, double-blind, saline-placebo trial; effectiveness ~80–90% against paralytic polio. (McGill Medicine, U-M School of Public Health)
Rotavirus (RotaTeq/Rotarix): Multiple double-blind, placebo-controlled phase-3 trials with >70,000 and >24,000 infants respectively. (U.S. Food and Drug Administration)
COVID-19 (Pfizer-BioNTech): Large randomized, placebo-controlled, observer-blinded trials (2020–22) showed high efficacy and acceptable safety before crossover. (New England Journal of Medicine)
HPV (Gardasil/Cervarix/Gardasil 9): Programs included adjuvant-only and saline controls in different studies, plus active-comparator designs (comparing new to established formulations). (U.S. Food and Drug Administration)

A crisp way to respond in conversation

Claim: “Vaccines aren’t studied with double-blind, placebo trials.”
Response: “That’s incorrect. When there’s no proven vaccine, trials do use double-blind, placebo controls—polio (1954), rotavirus (2000s), and COVID-19 (2020) are textbook examples. Once a vaccine is proven to work, ethics requires comparing new versions to the best available vaccine rather than depriving people of protection. That’s why you sometimes see active comparators instead of saline.” (McGill Medicine, U.S. Food and Drug Administration, New England Journal of Medicine, WMA)

Rotavirus

Rotaviruses are the most common cause of diarrhoeal disease among infants and young children. Nearly every child in the world is infected with a rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe. Adults are rarely affected.

The virus is transmitted by the faecal–oral route. It infects and damages the cells that line the small intestine and causes gastroenteritis (which is often called “stomach flu” despite having no relation to influenza). Although rotavirus was discovered in 1973 by Ruth Bishop and her colleagues by electron micrograph images and accounts for approximately one third of hospitalisations for severe diarrhoea in infants and children, its importance has historically been underestimated within the public health community, particularly in developing countries. In addition to its impact on human health, rotavirus also infects other animals, and is a pathogen of livestock.

Rotaviral enteritis is usually an easily managed disease of childhood, but among children under 5 years of age rotavirus caused an estimated 151,714 deaths from diarrhoea in 2019. In the United States, before initiation of the rotavirus vaccination programme in the 2000s, rotavirus caused about 2.7 million cases of severe gastroenteritis in children, almost 60,000 hospitalisations, and around 37 deaths each year. Following rotavirus vaccine introduction in the United States, hospitalisation rates have fallen significantly. Public health campaigns to combat rotavirus focus on providing oral rehydration therapy for infected children and vaccination to prevent the disease. The incidence and severity of rotavirus infections has declined significantly in countries that have added rotavirus vaccine to their routine childhood immunisation policies.
Rotavirus - Wikipedia

DDT poisoning caused Polio

Here’s the DDT–polio conspiracy in plain terms, followed by the facts that knock it down.

What the conspiracy claims

“Polio wasn’t caused by a virus; it was pesticide poisoning (esp. DDT).”
“Cases fell because DDT use stopped, not because of vaccines.”
“Polio was just renamed ‘acute flaccid paralysis’ (AFP) to fake a decline.”
Photos of 1940s–50s DDT spraying are offered as “proof” that poisoning—not infection—explains paralysis.

What the evidence actually shows

1) Polio is a viral disease, documented long before DDT existed

In 1908, decades before DDT’s mass use, Karl Landsteiner and Erwin Popper transmitted the disease to monkeys using filtered spinal cord material—proving a filterable virus caused polio. Later, the virus was visualized by electron microscopy and grown in culture, work that led to the 1954 Nobel Prize and made vaccines possible. (PubMed, FactCheck.org)
Pathology is classic: poliovirus selectively damages the anterior horn motor neurons in the spinal cord and brainstem, producing the asymmetric flaccid paralysis that defines paralytic polio—distinct from pesticide toxicity. (PubMed, Medscape)
Today the virus is routinely detected by culture/PCR from stool and throat specimens; genomes are sequenced and traced in outbreaks—something you simply cannot do with a poisoning theory. (CDC)

2) The timelines refute the DDT story

U.S. polio peaked in 1952 with >21,000 paralytic cases. Vaccines arrived in 1955 (IPV) and 1961 (OPV), after which incidence plunged rapidly; the last U.S. case of wild polio was in 1979. (CDC)
DDT’s general U.S. ban took effect in 1972, long after the sharp decline was already underway; in fact DDT use peaked in 1959—after the worst polio year and before vaccine-driven collapse. (US EPA, FactCheck.org)
Globally, wild polio has fallen >99% since 1988 due to vaccination, not pesticide policy. (World Health Organization)

3) Why the photos of DDT trucks don’t prove causation

Some U.S. communities sprayed DDT to kill flies during polio seasons, mistakenly thinking insects spread polio. That misguided response created striking images—but it’s backwards: spraying followed fear of polio; it didn’t cause it. (FactCheck.org)

4) “Polio was just renamed AFP” is false

AFP is a surveillance umbrella category (GBS, transverse myelitis, etc.) used to catch any paralysis and test for poliovirus; confirmed polio requires lab evidence of poliovirus. Surveillance expanded in the 1990s to detect residual polio, not to hide it. (GPEI, PMC)
Fact-checks and epidemiological data show the “polio-was-renamed” claim is incorrect; non-polio AFP conditions have different causes and distinct lab results. (Reuters)
U.S. data are decisive: paralytic polio dropped ~90% by 1960 and to 61 cases by 1965—well before any DDT ban or AFP-era bookkeeping could matter. (FactCheck.org)

5) Biological plausibility: poisoning vs. poliomyelitis

DDT toxicity at high doses can cause tremor, paresthesias, and seizures, but it doesn’t produce the specific pattern of anterior horn cell necrosis and asymmetric flaccid paralysis seen in polio. (National Pesticide Information Center, PubMed)

One-paragraph rebuttal you can use

“Polio is caused by a virus—proven in 1908, cultured, sequenced, and diagnosed from stool and throat samples. U.S. epidemics peaked in 1952 and collapsed after the 1955 and 1961 vaccines, with the last wild case in 1979. DDT was banned in 1972, years after polio had already plummeted. AFP isn’t a rename; it’s a surveillance net that still requires lab-confirmed poliovirus for a polio diagnosis. The global 99% drop in polio since 1988 tracks vaccination, not pesticide policy.” (CDC, US EPA, World Health Organization)
If you want, I can turn this into a one-page, citation-ready handout for debates.

Did the first cases of polio happen in rural communities and it happened to livestock as well?

Short answer: No.

Early outbreaks weren’t “rural-first.” Polio existed in humans long before modern pesticides and was described clinically by Michael Underwood (1789) and Jakob Heine (1840). The first large epidemics arose in the late 19th–early 20th centuries, especially in industrialized/urban settings (e.g., Scandinavia ca. 1905; the major 1916 New York City epidemic), and then spread widely each summer in developed countries until vaccines arrived in the 1950s–60s. (CDC, PMC, GPEI, Wikipedia)
Poliovirus does not infect livestock. Poliovirus’ natural host is humans (some nonhuman primates are susceptible experimentally), and public-health agencies note that humans are the only known reservoir. Surveys found no poliovirus in common domestic animals around patients. (ScienceDirect, ECDC, Oxford Academic)
Why people think animals get “polio”: Livestock have unrelated conditions historically nicknamed “polio,” such as:
- Polioencephalomalacia (PEM) in ruminants—a nutritional/toxic disorder (often thiamine deficiency or excess sulfur), not a virus. (Merck Veterinary Manual, AgriNatural Resources College)
- Teschen/Talfan disease (“porcine poliomyelitis”) in pigs—caused by teschoviruses, different picornaviruses that don’t infect people; the analogy to human polio is historical and clinical, not causal. (woah.org, PMC, Merck Veterinary Manual)

Bottom line: The historical record shows early epidemic polio centered in cities, not farm communities, and poliovirus is a human-specific pathogen—livestock don’t get human polio. (CDC, ECDC)

References

Anti-vaxxers - Jonathan M Berman
Anti-vaxxers - How to Challenge a Misinformed Movement — Jonathan M_ Berman (Annotated).pdf (file not included in this release)
Aluminum-Adsorbed Vaccines and Chronic Diseases in Childhood

Vaccines

Counter: Vaccines aren’t studied with double blind studies with placebos