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You might assume that all great medical discoveries are the result of deliberate action on the part of scientists. But you’d be wrong. Many great discoveries are the result of accidents, mistakes and chance. Here are five of the best, starting with the most recent.

1. Oxford vaccine dose

If the Oxford-AstraZeneca vaccine had been given at the specified dose, the effectiveness of the vaccine at stopping Covid-19 would have been a slightly disappointing 62%. (And I say “slightly disappointing” guardedly because it’s a good result, but next to Pfizer and Moderna’s 95% efficacy, it doesn’t look champagne-poppingly brilliant.)

In Brazil and South Africa, the Oxford vaccine was given at the correct initial dose, and the second dose a month later. But in the UK, the trial participants were incorrectly given half a dose in the first round and a full dose later. And, serendipitously, this resulted in 90% efficacy. Not only that, but the “wrong” dose also resulted in milder side-effects.

2. Penicillin

Perhaps the most famous serendipitous discovery in medicine is Alexander Fleming’s chance discovery of penicillin in 1928. Growing Staphylococcus bacteria that had been left on a bench, he noted on returning from holiday, that one of the plates he was culturing had no bacterial growth around a fungal colony that had started in the plate.

Fleming made his cultures of this fungus – penicillin – available far and wide. It would be one of his former students who first used it to treat a bacterial infection in 1930.

And it would be more than ten years later that penicillin was being produced in mass quantities to test its clinical effectiveness on patients, following groundbreaking work from Oxford University.

3. Culturing bacteria

The discovery and study of bacteriology by Robert Koch was a significant scientific advance. Before his work, bacteria were notoriously difficult to isolate from each other and were often grown in a nutrient broth that supports many species.

In 1872, Koch noted the growth of distinct colonies on a potato slice and this would be the catalyst for the use of agar, which is now the standard substance used to grow bacteria in a petri dish.

This discovery would allow scientists to isolate which bacteria were making a patient ill.

Koch’s work led to him discover the first causative bacteria of a named disease: Bacillus anthracis, which causes anthrax.

4. X-rays

The application of X-rays revolutionised medicine in the late 19th and early 20th century. Wilhelm Röntgen became aware of these new rays, which he called “X” because of their unknown origin, while studying cathode rays (streams of electrodes in vacuum tubes).

He noticed that the X-rays could penetrate cardboard, and he quickly used them to show they penetrated human tissues, too, using his wife’s hand to do so.

The application of these rays for looking inside the human body soon became widespread. There was little understanding of the damage they were doing. Many cases of symptoms typical of radiation sickness and exposure were documented, including famous scientists such as Thomas Edison.

5. Stomach ulcers

Over 4 billion people are estimated to be infected with H pylori, a bacterium that lives in the stomach and can cause ulcers. It was the tireless efforts of two researchers – Barry Marshall and J. Robin Warren – and a longer than usual growing period, that led to the discovery of the bacteria.

Before this, stress and certain foods were thought to cause stomach ulcers. While these factors can make ulcers worse, they don’t cause them.

In 1982, Marshall and Warren were studying the stomach lining and contents of several patients with varying gastric symptoms. The fortuitous positioning of the Easter weekend meant that cultures from patients were left alone in the lab longer than usual. This resulted in the identification of a slow-growing novel bacteria that was causing these symptoms.

Sadly, the reluctance of the scientific community to accept the findings of the scientists led to Marshall infecting himself with H pylori by consuming a live culture of bacteria, becoming symptomatic and then treating himself with antibiotics.

Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

South Africa has a long tradition of using plants for medicinal purposes. Some of these, such as Aloe ferox, Sutherlandia frutescens and Kiggelaria africana, have been studied as sources of useful compounds. But most still need to be scientifically validated as treatments for particular diseases.

Medicinal plants are gradually gaining prominence in scientists’ search for potential treatment agents for Covid-19. Currently there is no specific antiviral drug to treat this new respiratory disease. Most treatment strategies focus on managing symptoms and supportive therapy such as supplementary oxygen and mechanical ventilation.

My colleagues and I from the Durban University of Technology and the University of KwaZulu-Natal in South Africa are among the researchers looking for potential Covid-19 treatments from plants. We recently completed the first phase of our project, which ultimately seeks to develop a novel SARS-CoV-2 therapeutic.

Our aim in the first phase was to identify bioactive compounds in plants that are indigenous to South Africa which could be effective against SARS-CoV-2, the virus that causes Covid-19. We looked for potential Covid-19 therapeutic agents from a list of 29 bioactive compounds.

The species chosen were based on their use for the common cold, flu, other respiratory conditions, antimalarial, antiviral and antioxidant activity.

Our initial findings show that some compounds had the potential to inhibit SARS-CoV-2. We are now in the second phase of our study, which will test the compounds rigorously in the laboratory. This is a starting point in the search for a novel SARS-CoV-2 therapeutic.

From plant extract to therapeutic

In the initial stage of this project we worked with collaborators from the University of KwaZulu-Natal, Bio-computational and drug design laboratory. The team screened potential bioactive compounds isolated from commonly used South African medicinal plants using molecular docking.

Molecular docking is the study of how two or more molecular structures (for example, a drug and an enzyme or protein) fit together. Protein-binding may affect drug activity in one of two ways: either by changing the effective concentration of the drug at its site of action or by changing the rate at which the drug is eliminated, thus affecting the length of time for which effective concentrations are maintained.

We performed molecular docking of the plant compounds against SARS-CoV-2, using biocomputational analysis.

Some of the plant compounds showed potential. These were from Acacia senegal, Sutherlandia frutescens, Hypoxis hemerocallidea, Xysmalobium undulatum and Aspalathus linearis (commonly known as rooibos).

They exhibited favourable binding orientations and were identified as potential inhibitors of the SARS-CoV-2 receptor binding domain and SARS-CoV-2 RNA-dependent polymerase.

Four compounds exhibited extremely good binding to the virus, meaning that these compounds may prevent the virus from replicating.

These compounds could serve as a starting point for the discovery of a novel SARS-CoV-2 therapeutic.

Next steps

For the next stage we will infect animal cells with the virus. Then we’ll administer the compounds (cytotoxicity screening) to see what effect they have. If this in vitro study shows promising results, further analysis will be conducted using an animal model. The effects of the compounds on infected rats will be monitored.

Our end goal is to finally have a successful treatment for this virus. Infections can still occur even when a safe and effective vaccine is available. This is why it’s important to ensure effective treatments are also part of the efforts to end Covid-19.

No traditional African medicine has been scientifically validated yet as a treatment for SARS-CoV-2.

We are now in the second phase of our study, which will test the compounds rigorously in the laboratory if funding can be found. This depends on a lot of different factors.

We will be working with collaborators from the University of KwaZulu-Natal’s Department of Virology, where the analysis will take place.

Depika Dwarka, Post doctoral Fellow, Durban University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.