Did you get the jab?
- Sarah Hudleston
Not all clinical trials are vaccine trials, but it is mistrust around vaccines that threatens public health, demanding that trust in them be cultivated.
Clinical trials encompass a considerable range of medical research, all designed to test new health interventions on humans.
South African clinical trials, including vaccines, adhere to the highest ethical standards, say µÚÒ»³Ô¹ÏÍø scientists Professor Janan Dietrich, Director of the Bio-Behavioural Research Division of the Perinatal HIV Research Unit and Professor Sinead Delany-Moretlwe, both veterans of running clinical trials.
Trials are regulated by the South African Health Products Regulatory Authority via the South African Good Clinical Practice Guidelines, together with the National Health Act and Medicines and Related Substances Act. Although ‘vaccine hesitancy’ is not new, it was during the Covid-19 pandemic that the online vaccination furore exploded.
Pandemic pandemonium
Driven by social media, public debate over trust in vaccines intensified during the pandemic. Information, both negative and positive, often lacking credible research or expert validation, spread quickly outside traditional channels.
The pandemic was particularly damaging to trust levels, as it involved inconsistent public health messaging, emergency vaccine approvals and visible disagreements between experts. Public perception suggested that institutions were not transparent enough and that vaccine side effects were being minimised and not communicated honestly.
Post-pandemic narratives around the dangers of vaccinations for some population groups did not help and overall distrust was reflected in significant declines globally, including in South Africa, in childhood vaccines, as reported by UNICEF.
Shots fired at flu vax
Dietrich conducted a study on Covid vaccine acceptance and more recently headed the Bambisana study on the flu vaccine. She believes that the key to vaccine acceptance is both in the trust in health workers as well as in South Africa’s strict ethical guidelines when it comes to vaccine trials.
“During Covid-19, there was a high level of vaccine distrust amongst health workers, which influenced patient attitudes,” says Dietrich.
The Bambisana study set up four trial groups - one had a social media campaign only, another group had an in-person community engagement approach, a third group received both online and in-person engagement, which included the vaccine, and the fourth was the control group.
“What was surprising was that the control group, which had no real intervention apart from interaction with healthcare workers in clinics, saw an exponentially increased uptake of the vaccine,” says Dietrich. “All this proved that the key to trusting vaccines is people’s trust in their healthcare workers.”
Enduring mistrust
Delany-Moretlwe, Research Director at the says, “What we know about vaccines is that there is this phenomenon of mistrust. There have been many examples, particularly since the emergence of Covid-19, where people have felt that the health system has not been responsive to their needs. There will probably always be groups of people who mistrust government and, to some extent, technologies”.
She believes that the Covid-19 era amplified mistrust in government but vaccine-specific scepticism already existed.
“With increased access to social media and other sources of information, people may interpret things differently and they may hold fundamental beliefs that cannot easily be shifted.”
A case in point is when the Human Papillomavirus (HPV) vaccination programme was introduced into South Africa in 2014. “We detected a social media campaign spreading false information about the safety of the vaccines. While the Health Department ran a traditional media campaign, which was helpful, there was no comparable social media information campaign.”
HPV vaccine success despite mistrust …
Delany-Moretlwe ran a study to evaluate the impact of the HPV vaccine, aimed at preventing the later development of cervical cancer, which was administered to primary school girls in Grades 4 and 5.
“We measured infection rates and were gratified to see that the programme appeared to have reduced HPV infection by 80% even among those who were not vaccinated, which is what we term ‘herd protection’. This shows that investment in vaccines can have significant public health impacts and illustrates the importance of building trust in vaccines.”
… Yet measles re-emerges
The success of the HPV vaccine – despite all the disinformation – reinforces Delany-Moretlwe’s urgent advocacy of vaccination to protect public health. “In the US, there have been measles outbreaks because large sections of the population have stopped vaccinating.
The measles situation in Africa is equally alarming. A 2025 article by µÚÒ»³Ô¹ÏÍø bioethicists Subeshini Pillay, Cornelius Ewuoso and Lizeka Tandwa, illustrated a marked increase in measles outbreaks reported in some African countries (close to 400% between 2021 and 2022). In South Africa, although only 285 measles infections were recorded between 2015 and 2020, there were some 1 067 cases reported between 2022 and 2023.
Tandwa says that the latest stats show that the rate of measles infection continues to rise in South Africa, with 2 012 laboratory confirmed cases between December 2025 and 14 June 2026, with the Western Cape reporting the highest number of new cases.
Tandwa says, “Given that trust is a key predictor for vaccine hesitancy, building trust is essential for vaccine programme success”.
- Sarah Hudleston is a freelance writer.
- This article first appeared in CURIOS.TY, a research magazine produced by  and the .
- Read more in the 21st issue, themed #Trust — the invisible glue binding society, science and technology.