(2019) Impact of evidence-based science advice to government: Evidence from the health section in South Africa – SAYAS

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In February 2020, INGSA-Africa announced the winners of their 2019 Essay Competition.
Shortly after, the world was forced to pivot entirely to the threat of COVID-19 and regrettably, these essays were not celebrated in the way we would have liked
So even though the local and global context has now changed so much, we wanted to release the winning essays from 2019 and hope that you find them insightful despite the delay in their publication. 

Tozama Qwebani; Pradeep Kumar; and Adeyemi Oladapo Aremu
(Members of South African Young Academy of Science, SAYAS)


Since time immemorial, humans have based their decision on evidence accumulated over time which have ensured their survival and competitive advantage. In face of the diverse challenges facing humans today, the need and importance of science advice to government at different strata cannot be over-emphasised. Globally, there is an ever-growing recognition that science has an important role to play in virtually every dimension of policy making at every level of government, from local to international. Particularly, the health sector remain an important area that requires regular polices to ensure human health and general safety. The impact of evidence- based science advice to government will be discussed using the following three (3) examples from a South African perspective.


Case 1: The 20% tax on sugar-sweetened beverages (SSBs) to curb obesity in South Africa

In South Africa, an example of evidence-based science that has influenced government policy is the 20% tax on sugar-sweetened beverages (SSBs). The bill known as ‘the health promotion levy’ in the health sector provided for the implementation of a tax on sugary beverages. It was passed by the South African National Assembly on 21st November, 2017 and adopted for implementation in April, 2018 whereby a consumer will pay a tax of 2.1 cent for every gram of sugar per 100 ml above a 4 gram threshold. This tax was introduced as a measure to counter the increasing incidence of obesity among the population. Based on the World Health Organisation (WHO) reports, among African countries, South Africa has the highest obesity levels with 26.8% of people classified  as obese (https://www.wits.ac.za/news/latest-news/in-their-own-words/2017/2017-04/south- africa-needs-more-than-a-sugar-tax-to-get-to-the-bottom-of-obesity.html).            

South Africans are known for their high sugar intake with an average individual consuming between 12 and 24 teaspoons of sugar daily, and about 33% of these are from SSBs (https://www.wits.ac.za/news/latest-news/research-news/2016/2016-04/ssb-tax- home/sugar-facts/). Evidence of the harmful effects of sugar are well-known especially in children (https://www.wits.ac.za/news/latest-news/research- news/2016/2016-04/ssb-tax-home/sugar-facts/). Given the controversial nature and widely-divided public opinions as well as the anticipated economic challenges (including job losses) associated with this kind of law, scientific evidence was essential to inform the lawmakers to reach a decision. In the course of public engagement on the bill, researchers from the University of the Witwatersrand in Johannesburg, South Africa provided more credence with their timely research paper titled ‘The potential impact of a 20% tax on sugar-sweetened beverages on obesity in South African adults: A mathematical model’ (1).

The researchers interrogated evidence from the United Kingdom, Ireland, India and Brazil whereby policies such as a tax on SSBs reduced consumption thereby leading to reductions in population weight. They also predicted that the 20% SSB tax in South Africa will reduce obesity by 3.8% in adult males and 2.4% in females (1). The average reduction in energy intake is estimated to be 30.0 kJ per person per day. Furthermore the younger age-groups are the biggest consumers of SSBs and will potentially benefit most from the SSB tax. The implementation of this sugar tax in South Africa is a first among African countries and nicely highlights the role of scientific evidence in advising the government leading to formulation of robust policy and law.


Case 2: Evidence-based guidelines and professional recommendations for vaccination in HIV-patients – a local perspective.

Time and again, scientific research has provided evidence for the safety and efficacy of vaccines as well as guidelines and recommendations for the use of vaccines for vaccine preventable diseases (VPDs). Of global significance, the evidence-based scientific research in vaccinology has repeatedly rejected claims that “autism is caused by vaccines” (2). In the South African local perspective, with over 7 million people living with HIV and an HIV prevalence of over 20% among the general population (3), formulation of general guidelines applicable to all would be very challenging. A recent report published by Dlamini et al. (2018) in Southern African Journal of HIV Medicine provided Guidelines for the vaccination of HIV-infected adolescents and adults in South Africa (4). The guidelines were drafted on evidence- based research which has shown that “The use of vaccines in the HIV-infected is generally safe and causes no harm among patients with CD4+ counts above 200 cells/μL and with very low viral load (< 50 copies/mL).”

The report provided detailed guidelines for vaccines with strong local evidence for use such as influenza (one annual dose irrespective of CD4+ count and viral load), pneumococcal infections (prime-boost approach), hepatitis B (Four-double-dose regimen), Tetanus-diphtheria (Td) (irrespective of CD4+ count), and human papilloma virus (irrespective of CD4+ count, ART use or viral load). The above information confirms that evidence-based research is required to make an informed decision related to vaccine-specific regimens. In addition, evidence-based research does not recede from accepting that further data/research/evidence is required or warranted to reach/drafting a definitive conclusion/guideline with respect to vaccines such as pertussis, meningococcal infections, and hepatitis A.

Furthermore in some cases, such as zoster vaccine, there are reported benefits but ideal dosing schedule is yet to be established. Yet again, scientific evidence prevailed over generalizations. The SA HIV Clinicians Society (SAHCS) has developed several guidelines over the years including the recent Antiretroviral Drug Dosing Chart for Children (2019) as compiled by Child and Adolescent Committee of the SAHCS in collaboration with the Department of Health.


Case 3: The safety of Traditional Medicine with special focus on dosages and toxicity

People from the Southern African region have been using the fauna and flora of the region in their homes for millennia to treat all sorts of ailments and complaints with great success. This knowledge transfer was done through “apprenticeships” and oral communication. However the challenge remains that these medicines have not been tested through a comprehensive evidence based scientific or clinical study. There is a fallacious view that herbal medicines are harmless and free of side effects because they are “natural”. In recent times, there have been several cases of hepatic injury and even death associated with their use (5). For instance, in South Africa, the administration of the traditional Zulu remedy impila (Callilepis laureola) in high doses results in severe or fatal hepatotoxicity and, in some cases, nephrotoxicity. Patients poisoned with impila characteristically show severe hypoglycaemia as a precursor to catastrophic hepatocellular necrosis (6-9).

We aim to assist the Department of Health (DOH) to counter the challenges faced with regards to the acceptable use of African Traditional Medicine (ATM). This will be done through toxicity study and dosage measurements. Direct reason is the intrinsic toxicity of some herb at normal therapeutic dosage or in overdose. Adverse reactions associated with Ephedra, Aristolochia, and Aconitum have shown that herbs can produce toxicity in humans (10). Adverse effects associated with herbal medicines may result from contamination of products with toxic metals, adulteration, misidentification or substitution of herbal ingredients, or improperly processed or prepared products (10). For example, Caulis Akebiae replaced by Caulis Aristolochiae Manshuriensis and Stephania tetrandra replaced by Aristolochia fangchi have led to the serious problem of “aristolochic acid nephropathy.”

In this project we will adopt the methodology used to produce Chinese Pharmacopoeia of 2010 while working with South African Biodiversity.



The three cases highlighted above is an indication of the increasing impact of evidence-based science advice to government in South African health sector. As researchers, there is need to always remember the three secrets of survival in science advice which include ‘be impartial, humble and good value’ in order to remain the catalyst for change in our communities. It is also essential that researchers bring the rigour of a scientific mind to government facilitated by good communication skills and tools.



  1. Manyema, , Veerman, L.J., Chola, L., Tugendhaft, A., Sartorius, B., Labadarios, D., Hofman, K.J., 2014. The potential impact of a 20% tax on sugar-sweetened beverages on obesity in South African adults: A mathematical model. PLOS ONE 9(8), e105287.
  2. Vaccine Safety, Evidence-Based Research Must Prevail, Dimensions of Critical Care Nursing: 2017 – Volume 36 – Issue 3 – p 145–147, doi: 1097/DCC.0000000000000250.
  3. https://avert.org/professionals/hiv-around-world/sub-saharan-africa/south- africa
  4. Dlamini SK, Madhi SA, Muloiwa R, et al. Guidelines for the vaccination of HIV- infected adolescents and adults in South Africa. S Afr J HIV Med. 2018;19(1), a839. https://doi.org/10.4102/sajhivmed.v19i1.839
  5. Vaccination among HIV-infected, HIV-exposed uninfected and HIV-uninfected children: a systematic review and meta-analysis of evidence related to vaccine efficacy and effectiveness
  6. Popat A, Shear N H, Malkiewicz I, Michael J. Stewart MJ, Steenkamp V et al: The toxicity of Callilepis laureola, a South African traditional herbal
  7. Seedat Y, Hitchcock Acute renal failure from Callilepis laureola. S Afr Med J 1971; 45: 832- 33.
  8. Wainwright J, Schonland M. Toxic hepatitis in black patients in Natal. S Afr Med J 1977; 51: 571-73.
  9. Bhoola K. A clinico-pathological and biochemical study of the toxicity of Callilepis laureola (Impila) in Medicine, University of Natal, Durban
  10. Watson A, Coovadia H, Bhoola K. The clinical syndrome of Impila (Callilepis laureola) poisoning in children. S Afi Med J 1979; 65: 290-92.
  11. Zhang J., Wider B., Shang H., Li X., Ernst E. Quality of herbal medicines: challenges and Complementary Therapies in Medicine. 2012;20(1-2):100– 106.