The scientific process during the COVID-19 pandemic
By Maria-Cecilia Costa
Since the COVID-19 pandemic started, the world has turned its eyes to science as its best hope to win against this new virus. As research groups joined efforts, results came out faster than ever and everyone had a glimpse at science working in real time. Unfortunately, part of this was that preliminary results were promoted as conclusive and people were frustrated by scientific news pointing in different directions. This showed that many people do not really understand how science works. How well do you understand it?
The scientific method
The way scientists work is based on a “scientific method”, which is a process used to explore observations and answer questions. The way this process is conducted is different in each field. This is because some fields are more reliant on lab experiments (such as the medical field) while other fields are more theoretical (such as economic sciences). Regardless of the field, scientists ask questions based on facts (observations) and formulate hypotheses to answer them.
Scientific hypotheses are suggested answers to the original question. It is very important that these hypotheses can be carefully tested in a way that gives room for confirming or refuting them. It is bad science to test a hypothesis in a way that only allows it to be confirmed. This is the foundation of how science evolves and our knowledge advances.
After formulating and testing hypotheses, scientists try to combine everything into a logical answer to the original question. This process is repeated multiple times until a concise body of knowledge is built that can explain the initial facts.
If you want to know more about the scientific method, check out this talk on how science works given at a @15x4munich event by @shasanrr .
How does the COVID-19 pandemic fit into this scientific method?
On 31 December 2019, the World Health Organization (WHO) was formally notified about a cluster of cases of pneumonia in Wuhan City, Hubei province, China. Based on this fact, a question immediately came up: what is causing it? Scientists then formulated the hypothesis that a new virus was the cause and proceeded to testing it.
To test their hypothesis, they investigated some people that were severely ill. They found and sequenced the genome of a virus isolated from these people. When they looked closely at the sequence, their hypothesis was confirmed: the virus was a novel coronavirus, called SARS-CoV-2 or COVID-19.
What is the origin of the new virus?
A new question then emerged: what is the origin of this new virus? COVID-19 is not the first coronavirus to cause outbreaks of respiratory infection in humans. Six others have already been identified, all likely having originated in animals. Then, scientists came up with the hypothesis that COVID-19 has also originated in animals.
Many of the early COVID-19 cases were linked to the Huanan seafood market in Wuhan and environmental samples taken from the market were positive for COVID-19. The best way to test the hypothesis would have been to analyze samples collected from animal species available for purchase in the market. However, the market was cleared soon after the outbreak began. Scientists then had to look for data already available from other studies on viruses from animals. They found similarities between COVID-19 and a virus from bats. Their hypothesis was confirmed!
It is common in science that different groups working on the same topic find different results. This might happen because each group approaches a problem from a different perspective or because they consider different factors when planning their analyses, for example they use different databases or use different thresholds to evaluate their data. For COVID-19, although other groups confirmed that the likely sources of the virus were animals, their results landed in different species.
Pangolins are one of the most illegally trafficked mammal species. They are used as a food source and their scales are used in traditional Chinese medicine. A research group looked at the viruses present in pangolins and found that they were even more similar to COVID-19 than the bat virus. Therefore, the hypothesis that COVID-19 came from pangolins became the most accepted hypothesis. As scientists keep looking at it, this hypothesis can either be confirmed or refuted by other groups.
Modeling
While the origin of the virus was being investigated, the focus of the scientific questions around the outbreak changed. Questions about the modes of transmission and the best ways to contain the virus started to be asked.
In March 2020, the epicenter of infections moved from Asia to Europe and the number of infected people went from 2,000 to almost 60,000. Policymakers tried to design plans to contain the virus and avoid the collapse of their health care systems and their economies. They turned to academic modelers for guidance.
Models are representations of selected parts or aspects of the world. Often, they involve deliberate simplifications or distortions of something complicated with the objective of making it more tractable or understandable. Models are used to test ideas and processes in ways that may be impossible to do in the real world. They are also used to identify, understand and predict patterns in our world. As there are no fixed rules or recipes for model building, models built to represent the same phenomena can end up being very different from each other.
As expected, scientists came up with different models concerning COVID-19. Some of these models aimed at predicting the risk of developing a COVID-19 infection or being admitted to hospital with it. Others aimed at predicting the prognosis or course of infection in patients diagnosed with COVID-19. Some other models aimed at predicting the growth rate of infections and the effect of certain interventions on it. Policymakers adopted different models according to the realities of their regions and what they thought was the best mode of action.
Many of these models became available as preprints in repositories, ahead of peer review. It means that journalists and the public had access to all this information without any filters.
Getting the results out to the public — peer reviewing and publishing
A big part of how science works is disseminating the results by publishing them in a scientific journal. Research not published is equivalent to research not done. In the process of publishing, the work is validated and a dialog with fellow researchers opens up.
The most popular way to do it is by writing a scientific article/paper and sending it to a scientific journal. The editor of that journal then evaluates the article and, if it fits the scope of the journal, sends it for peer-reviewing. During peer-review, the work is validated by typically 2 to 4 scientists working on the same or a similar topic (but having no conflict of interests). These scientists carefully read the article and usually comment on it by making suggestions for improvements and asking questions to clarify points that are not clear to them. From peer review, the article gets sent back to the authors. Once the authors have considered the reviewers’ suggestions, answered the raised questions, and modified the article accordingly, the article returns to the journal. This process starts again until the editors and reviewers are satisfied with the quality of the article. If the article is rejected, the authors work on the missing fatal points that led to the rejection in the first place and then start all over again at a different journal until the paper gets accepted for publication.
During the COVID-19 pandemic, many articles about the virus (by April, 6,000 out of 16,000) were posted as preprints in repositories (Fraser et al., 2020). This means that they were immediately available to the public, without having to go through the lengthy process of peer-reviewing. However, as these articles were not peer-reviewed, they were also not edited, typeset or checked for scientific quality. This was exactly when the preliminary results were taken as conclusive, leading to misinformation and potential risks to public health.
One example of this was the research about COVID-19 about hydroxychloroquine and chloroquine medications. Some preliminary studies suggested that these medications could prevent the infection or shorten the duration of symptoms. This was enough evidence for some influential people to start promoting them, leading to global supply shortages and some cases of poisoning. However, subsequent larger scale trials showed that they are not effective as a treatment and have no positive effect at all. The US Food and Drug Administration (FDA) ended up withdrawing the drug and the World Health Organization (WHO) advising people against it.
Science works!
Now that you understand better how science works, next time you hear claims based on scientific evidence, check out the origin of this evidence! Also, check the hypothesis and the methods used to test it. Do they make any sense to you? Of course this will be easier for some areas of knowledge than for other areas depending on your background. But you can always check if the article has been peer-reviewed and if other articles are supporting its findings.
If you would like to read more such blogs, subscribe to the publication https://medium.com/15x4munich.
Meanwhile, follow us on other social media platforms and stay tuned for more events and knowledge:
To read more:
