OPINION: What the vaccine debate gets right, and wrong, about medical research

This week, social media has been awash with commentaries on vaccines. The debate began after a social media user claimed that women were increasingly being diagnosed with endometriosis as a consequence of vaccination. What followed was an important but polarised debate about vaccine safety and the ethical boundaries of clinical research, particularly in African populations.

To put this debate into perspective, we need to understand how researchers establish whether an exposure is responsible for a health outcome. An event occurring after another does not, by itself, establish a relationship. Researchers look for consistent patterns across populations while accounting for confounding factors. These are other characteristics that may influence both the exposure and the outcome.

A woman may receive a vaccine and subsequently be diagnosed with endometriosis, but the diagnosis may reflect a condition that existed beforehand, differences in healthcare-seeking behaviour, or other factors. Endometriosis can take years to diagnose, so an increase in diagnoses following vaccination requires investigation rather than an assumption of causation.

A similar claim has been made about children diagnosed with autism after their mothers were vaccinated during pregnancy. The experience of a family is real and deserves to be heard, but individual experiences cannot establish whether vaccination increased the child's risk.

Autism is a complex neurodevelopmental condition involving multiple genetic and environmental factors. The World Health Organization’s 2026 review of evidence published between 2010 and 2025 found that the strongest available studies do not support a causal association between vaccination during pregnancy and autism.

The controversy surrounding vaccines and autism also demonstrates the importance of evidence. Much of the modern debate can be traced to a 1998 paper claiming an association between the Measles, Mumps and Rubella (MMR) vaccine and autism. The paper was subsequently retracted over serious methodological and ethical concerns, and its principal author was struck off the UK medical register. Subsequent research has repeatedly examined the claim, with WHO's latest review finding no evidence supporting a link between vaccines and autism.

None of this means vaccines should be beyond scrutiny. Vaccines are medical products and should undergo rigorous clinical trials, regulatory review and continuing safety surveillance. When credible safety signals emerge, they should be investigated transparently. Public confidence is not built by pretending that medical interventions are perfect.

There are also legitimate reasons for some of the distrust surrounding medical research in the African population. The history of medicine contains serious violations of the rights of vulnerable populations. In 1932, the U.S. Public Health Service began studying hundreds of Black men with syphilis in Tuskegee, Alabama. Participants were not properly informed about their diagnosis, and even after penicillin became the standard treatment, researchers withheld treatment to observe the progression of the disease. The study continued until 1972, when it was exposed and brought to an end.

Tuskegee was not an African study, but its significance extends beyond the United States. It remains a powerful example of how racial inequality, exploitation and violations of informed consent can destroy public trust in medicine. For African populations, it also resonates with a broader history of unequal relationships between researchers, governments and communities.

This history does not demonstrate that contemporary vaccines are instruments of population control. It does, however, explain why demands for transparency, informed consent and independent ethical oversight are legitimate.

This brings us to another claim frequently encountered in African vaccine debates: that Africans are being used as "guinea pigs." To understand why this language resonates, we need to understand the origins of modern research ethics. Following the Second World War, Nazi physicians were prosecuted for conducting medical experiments on concentration-camp prisoners without their consent. The subsequent Nuremberg Doctors' Trial led to the articulation, in 1947, of ten principles governing permissible human experimentation, which became known as the Nuremberg Code.

At its centre was the principle of voluntary consent. Participants should understand the nature and risks of research, unnecessary suffering should be avoided, and experiments should be stopped when continuation could cause unacceptable harm. The Nuremberg Code helped establish a principle that remains fundamental today; scientific progress cannot come at the expense of human dignity and autonomy.

Contemporary clinical research is governed by ethical review, informed consent, safety monitoring and regulatory oversight. These safeguards exist because the abuses of the past demonstrated what can happen when scientific ambition is allowed to override human rights.

There is, however, an important irony in the "guinea pig" argument. Africa's problem in global clinical research is arguably not that there are too many trials involving Africans, but that there are too few. The continent remains substantially underrepresented in global clinical research relative to its population and disease burden.

The answer should therefore be greater African participation in ethical, properly regulated research. Kenyan scientists should lead clinical studies. Kenyan universities and hospitals need the infrastructure and funding to conduct world-class research. African regulators need the capacity to independently scrutinise trials and medicines. Most importantly, African patients should be adequately represented in research addressing the diseases and health priorities of their communities.

[The writer is a Masters of Public Health/Global Health student, UNSW.]