A new virus is taking over the world. In March 2020, Switzerland was faced with an “extraordinary situation”, and the second wave started sweeping across the country from October onwards. However, for many researchers in the ETH Domain that was no reason to despair, but rather an appeal and motivation to put their problem-solving skills to good use by tackling current and urgent challenges.

Martin Ackermann, Professor of Microbial Systems Ecology at ETH Zurich

A new type of respiratory disease spread like wildfire all over the world from a seafood market in the city of Wuhan, which is located in central China and has more than 11 million inhabitants. In Switzerland, the Federal Council declared an “extraordinary situation” in mid-March 2020 due to the coronavirus pandemic. Whereas schools and businesses were forced to close and public life virtually came to a halt, the research community in Switzerland went beyond the call of duty. Numerous scientists are committed to doing their part to help overcome the crisis.

Minimising damages and

“It is an exceptional privilege for me to chair the national scientific task force,” says Martin Ackermann. As a Professor of Microbial Systems Ecology at ETH Zurich and Head of the Department Environmental Microbiology at Eawag, he is interested in the fundamental questions of evolution. Together with his group, he is investigating, for instance, how genetically identical bacterial cells differ in their behaviour. Superficially, this has nothing to do with the occurrence of infection with the new virus. However, whoever takes a closer look will notice that the methods of mathematical biology and interdisciplinary cooperation play a major role where both issues are concerned.

“It impresses me how constructively people work together.” Martin Ackermann, Chair of the Swiss National COVID-19 Science Task Force

The independent expert panel, which advises and supports the federal government and cantons, is made up of about researchers. In ten different groups, they develop basic scientific principles challenges. issues ranging from the prevention of transmission to economic effects and modelling of the number of beds in intensive care wards. Professor Ackermann was a founding member of the task force, and he has been leading it since August. Even though his new duty is very time-consuming, he gets a lot out of it. “It impresses me how constructively people work together.” He says that he noticed that in public debates, economic and health-related well-being are often presented as being opposing poles. However, he adds, the task force members agree that the objective must be to minimise both health-related damages and societal costs. “The lower the case numbers, the greater the economic freedom,” says professor

Newly invented contact tracing

Whoever wants to keep case numbers low must be able to break the virus’s transmission chains. Contact tracing plays an important role here. Southeast Asian countries like Taiwan or South Korea have found an effective response to the pandemic by quickly locating and isolating anyone who was in the vicinity of an infected person. “However, as part of these procedures, these countries also resort to using data which should remain confidential from a privacy perspective,” says Carmela Troncoso, Computer Science Professor at EPFL. “We asked ourselves what data is absolutely essential for contact tracing and then reinvented the technology within six weeks, so that only this data is collectet."

The new proximity-tracing protocol, which professor Troncoso designed with her colleagues, is called DP3T (“Decentralised Privacy-Preserving Proximity Tracing”). DP3T is based on regularly generated random IDs which are exchanged between smartphones via Bluetooth. During this process, that data remains stored in the user’s phone. “We advised both Apple and Google on implementing the new Bluetooth interface,” says Srđjan Čapkun, Professor at the Institute of Information Security, who was involved in the development of DP3T in the capacity of Director of the System Security Group at ETH Zurich. “The protocol is now used by the Federal Office of Public Health’s SwissCovid app, but numerous other European countries have also adopted our approach,” says Professor Troncoso. Her persuasive argument: the new technology ensures that nobody can access personal information (such as GPS location data), so that neither Apple nor Google, nor the authorities, can collect private data using the contact-tracing app.

Virtual briefings for avalanche bulletins

Necessity is the mother of invention. Thomas Stucki and his team from the avalanche warning service at the WSL Institute for Snow and Avalanche Research SLF in Davos had to come up with something new when they – like the majority of the Swiss population – were not allowed to go to their workplace during the shutdown. “The daily avalanche bulletins are a joint effort,” says Th. Stucki. He adds that there are always at least three people on duty who meet for a fixed joint briefing at 3:00 p.m. every day to share their risk assessments. “Normally, we sit at the table with printed maps which we show each other during the meeting,” says Th. Stucki.

He adds that during virtual Zoom briefings, they pointed out disputed points to each other on the screen and the majority of non-verbal communication was lost during this process. “Fortunately, the avalanche situation in March and April was favourable,” says Th. Stucki. “This enabled us to practise the procedures while working from home.” The avalanche warning service is now also equipped for a natural disaster which could cut the SLF off from the rest of the country and keep avalanche forecasters away from their workplace.

Light for 3D X-ray microscopy

The COVID-19 crisis also released inventive energy at the PSI. Even though most research institutions worldwide stopped operating during the pandemic, the large research facilities in Villigen, such as the Swiss Light Source (SLS), kept operating. The SLS supplies very bright X-ray light, with which, for example, the structures of proteins can be broken down to atomic level. Proteins are the most important “building materials” and the “molecular tools and machines” in all living systems, including the new SARS-CoV-2 virus. “Our employees benefited during the pandemic from the possibility of remote-controlled sampling using a robotic gripper arm at the measuring stations. In this way, researchers were able to analyse the structures of the SARS-CoV-2 proteins at any time”, says Professor Gebhard Schertler, Head of the Research Division of Biology and Chemistry at the PSI. “At the same time, we the Board of Directors of the PSI, decided to launch a scientific programme on the topic of COVID-19.”

Within a few weeks, researchers at the PSI initiated 11 new projects. For instance, a project was launched with the aim of using the bright SLS X-ray light to examine lung tissue samples of COVID-19 patients using a new X-ray imaging method developed at the PSI. If the illness is severe, the immune system attacks the lungs in a type of overreaction. As a result, mosaicked water inclusions form in the tissue, which make it difficult to breathe or even make it impossible to do so. “With the help of three-dimensional X-ray microscopy, we want to find out in greater detail what is happening and what can be done to avoid such lung damage if at all possible,” says Professor Schertler.

Optical sensor for identifying SARS-CoV-2

The research group led by Professor Jing Wang at ETH Zurich and Empa also responded by realigning its scientific expertise. Until now, the team had mainly focused on measuring and analysing air pollutants like nanoparticles or aerosols and conducted research on, amongst other things, sensors which can detect bacteria in the air. “We used these foundations and developed our optical sensor in such a way that it can specifically detect SARS-CoV-2 viruses in the air,” says Wang. The new sensor consists of tiny golden structures – Professor Wang talks about “golden nano islands” – upon which he and his co-workers have grafted fragments of genetic material. These DNA fragments are complementary to the genetic sequence of SARS-CoV-2 and can therefore fuse with the single-stranded viral DNA.

When the famous double helix is thus formed, this also leads to a change in the distribution of electron clouds in the gold nanoparticles, which J. Wang and his team can measure using a spectrometer thanks to a quantum-mechanical effect (which is invisible to the human eye). “In addition, we can plasmonically excite the golden nano islands with a green laser light. This results in an increase in temperature, and virus sequences which do not match perfectly break away from the DNA fragments on the nano gold,” says Professor Wang. “That is why our sensor can also distinguish the SARS-CoV-2 virus from the closely related SARS-CoV virus.” Wang thinks that they will nevertheless have to overcome several other hurdles in development before it is possible to make reliable measurements in the air using the sensor.

Waste water analyses as a contribution during the coronavirus crisis

Researchers at EPFL have also developed a new detection method for the pathogen COVID-19 in cooperation with colleagues at Eawag. It might surprise you at first that you can make a contribution to overcoming the COVID-19 crisis with waste water analyses. “However, waste water analyses in Israel have, for example, already helped to contain an outbreak of the polio pathogen,” says Professor Tamar Kohn, head of the Environmental Chemistry Laboratory at EPFL. “Worldwide, environmental monitoring is playing an increasingly important role in fighting diseases,” adds Christoph Ort, Eawag research group leader in the Department of Urban Water Management.

Since the end of February 2020, employees of both research groups have been collecting waste water samples from Lausanne, Lugano and Zurich. “Initially, we were virtually flying blind. Only over time did we discover how we had to prepare and purify the samples in order to burst open the virus shell and examine the genetic material contained therein,” explains Professor Kohn. Unlike the individual tests, which search for the genetic material of SARS-CoV-2 in smears of the mucous membranes of the throat, the waste water tests do not allow a conclusion to be drawn about individuals’ infection with the virus.

Breaking new ground in times of crisis

Professor Kohn and Ch. Ort both think that in any case, only about half of the people infected excrete viruses through their faeces, which is why their analyses will by no means replace the PCR tests currently in use but rather complement them sensibly. This is because: “We can gain an overview of large sections of the population from waste water and can quickly identify where new disease outbreaks occur,” says Professor Kohn. Ch. Ort has already been dealing with waste water analyses for more than a decade, a field which led a shadowy existence for a long time. “Our work was suddenly thrust into the limelight,” says Ch. Ort. Now, the researchers are spending lots of time and energy on meeting the huge interest in the new coronavirus and answering the many questions they receive.

Overall, numerous scientists from the ETH Domain are demonstrating special commitment. By postponing their other research priorities, they are demonstrating their flexibility and contributing to overcoming the current crisis on many different fronts. That is why Switzerland’s policy of maintaining a high-quality research landscape with sufficient funding is now paying off. It is at moments like this that Switzerland can rely not only on the researchers’ excellent expert knowledge but also on their impressive ability to solve problems. They are used to dealing with uncertainties in their daily work and are especially capable of breaking new ground in times of crisis.