Researchers Are Designing a Biosensor to Detect Viruses in Transit Hubs and Hospitals
The unprecedented scale and impact of the COVID-19 pandemic has caused scientists and engineers around the world to stop whatever they were working on and shift their research toward understanding a novel virus instead.
"We have confidence that we can use our system in the next pandemic."
For Guangyu Qiu, normally an environmental engineer at the Swiss Federal Laboratories for Materials Science and Technology, that means finding a clever way to take his work on detecting pollution in the air and apply it to living pathogens instead. He's developing a new type of biosensor to make disease diagnostics and detection faster and more accurate than what's currently available.
But even though this pandemic was the impetus for designing a new biosensor, Qiu actually has his eye on future disease outbreaks. He admits that it's unlikely his device will play a role in quelling this virus, but says researchers already need to be thinking about how to make better tools to fight the next one — because there will be a next one.
"In the last 20 years, there [have been] three different coronavirus [outbreaks] ... so we have to prepare for the coming one," Qiu says. "We have confidence that we can use our system in the next pandemic."
"A Really, Really Neat Idea"
His main concern is the diagnostic tool that's currently front and center for testing patients for SARS-Cov-2, the virus causing the novel coronavirus disease. The tool, called PCR (short for reverse transcription polymerase chain reaction), is the gold standard because it excels at detecting viruses in even very small samples of mucus. PCR can amplify genetic material in the limited sample and look for a genetic code matching the virus in question. But in many parts of the world, mucus samples have to be sent out to laboratories for that work, and results can take days to return. PCR is also notoriously prone to false positives and negatives.
"I read a lot of newspapers that report[ed] ... a lot of false negative or false positive results at the very beginning of the outbreak," Qiu says. "It's not good for protecting people to prevent further transmission of the disease."
So he set out to build a more sensitive device—one that's less likely to give you a false result. Qiu's biosensor relies on an idea similar to the dual-factor authentication required of anyone trying to access a secure webpage. Instead of verifying that a virus is really present by using one way of detecting genetic code, as with PCR, this biosensor asks for two forms of ID.
SARS-CoV-2 is what's called an RNA virus, which means it has a single strand of genetic code, unlike double-stranded DNA. Inside Qiu's biosensor are receptors with the complementary code for this particular virus' RNA; if the virus is present, its RNA will bind with the receptors, locking together like velcro. The biosensor also contains a prism and a laser that work together to verify that this RNA really belongs to SARS-CoV-2 by looking for a specific wavelength of light and temperature.
If the biosensor doesn't detect either, or only registers a match for one and not the other, then it can't produce a positive result. This multi-step authentication process helps make sure that the RNA binding with the receptors isn't a genetically similar coronavirus like SARS-CoV, known for its 2003 outbreak, or MERS-CoV, which caused an epidemic in 2012.
It could also be fitted to detect future novel viruses once their genomes are sequenced.
The dual-feature design of this biosensor "is a really, really neat idea that I have not seen before with other sensor technology," says Erin Bromage, a professor of infection and immunology at the University of Massachusetts Dartmouth; he was not involved in designing or testing Qiu's biosensor. "It makes you feel more secure that when you have a positive, you've really got a positive."
The light and temperature sensors are not in themselves new inventions, but the combination is a first. The part of the device that uses light to detect particles is actually central to Qiu's normal stream of environmental research, and is a versatile tool he's been working with for a long time to detect aerosols in the atmosphere and heavy metals in drinking water.
Bromage says this is a plus. "It's not high-risk in the sense that how they do this is unique, or not validated. They've taken aspects of really proven technology and sort of combined it together."
This new biosensor is still a prototype that will take at least another 12 months to validate in real world scenarios, though. The device is sound from a biological perspective and is sensitive enough to reliably detect SARS-CoV-2 — and to not be tricked by genetically similar viruses like SARS-CoV — but there is still a lot of engineering work that needs to be done in order for it to work outside the lab. Qiu says it's unlikely that the sensor will help minimize the impact of this pandemic, but the RNA receptors, prism, and laser inside the device can be customized to detect other viruses that may crop up in the future.
"If we choose another sequence—like SARS, like MERS, or like normal seasonal flu—we can detect other viruses, or even bacteria," Qiu says. "This device is very flexible."
It could also be fitted to detect future novel viruses once their genomes are sequenced.
The Long-Term Vision: Hospitals and Transit Hubs
The device has been designed to connect with two other systems: an air sampler and a microprocessor because the goal is to make it portable, and able to pick up samples from the air in hospitals or public areas like train stations or airports. A virus could hopefully be detected before it silently spreads and erupts into another global pandemic. In the case of SARS-CoV-2, there has been conflicting research about whether or not the virus is truly airborne (though it can be spread by droplets that briefly move through the air after a cough or sneeze), whereas the highly contagious RNA virus that causes measles can remain in the air for up to two hours.
"They've got a lot on the front end to work out," Bromage says. "They've got to work out how to capture and concentrate a virus, extract the RNA from the virus, and then get it onto the sensor. That's some pretty big hurdles, and may take some engineering that doesn't exist right now. But, if they can do that, then that works out really quite well."
One of the major obstacles in containing the COVID-19 pandemic has been in deploying accurate, quick tools that can be used for early detection of a virus outbreak and for later tracing its spread. That will still be true the next time a novel virus rears its head, and it's why Qiu feels that even if his biosensor can't help just yet, the research is still worth the effort.
It could also be fitted to detect future novel viruses once their genomes are sequenced.
The dual-feature design of this biosensor "is a really, really neat idea that I have not seen before with other sensor technology," says Erin Bromage, a professor of infection and immunology at the University of Massachusetts Dartmouth; he was not involved in designing or testing Qiu's biosensor. "It makes you feel more secure that when you have a positive, you've really got a positive."
The light and temperature sensors are not in themselves new inventions, but the combination is a first. The part of the device that uses light to detect particles is actually central to Qiu's normal stream of environmental research, and is a versatile tool he's been working with for a long time to detect aerosols in the atmosphere and heavy metals in drinking water.
Bromage says this is a plus. "It's not high-risk in the sense that how they do this is unique, or not validated. They've taken aspects of really proven technology and sort of combined it together."
This new biosensor is still a prototype that will take at least another 12 months to validate in real world scenarios, though. The device is sound from a biological perspective and is sensitive enough to reliably detect SARS-CoV-2 — and to not be tricked by genetically similar viruses like SARS-CoV — but there is still a lot of engineering work that needs to be done in order for it to work outside the lab. Qiu says it's unlikely that the sensor will help minimize the impact of this pandemic, but the RNA receptors, prism, and laser inside the device can be customized to detect other viruses that may crop up in the future.
"If we choose another sequence—like SARS, like MERS, or like normal seasonal flu—we can detect other viruses, or even bacteria," Qiu says. "This device is very flexible."
It could also be fitted to detect future novel viruses once their genomes are sequenced.
The Long-Term Vision: Hospitals and Transit Hubs
The device has been designed to connect with two other systems: an air sampler and a microprocessor because the goal is to make it portable, and able to pick up samples from the air in hospitals or public areas like train stations or airports. A virus could hopefully be detected before it silently spreads and erupts into another global pandemic. In the case of SARS-CoV-2, there has been conflicting research about whether or not the virus is truly airborne (though it can be spread by droplets that briefly move through the air after a cough or sneeze), whereas the highly contagious RNA virus that causes measles can remain in the air for up to two hours.
"They've got a lot on the front end to work out," Bromage says. "They've got to work out how to capture and concentrate a virus, extract the RNA from the virus, and then get it onto the sensor. That's some pretty big hurdles, and may take some engineering that doesn't exist right now. But, if they can do that, then that works out really quite well."
One of the major obstacles in containing the COVID-19 pandemic has been in deploying accurate, quick tools that can be used for early detection of a virus outbreak and for later tracing its spread. That will still be true the next time a novel virus rears its head, and it's why Qiu feels that even if his biosensor can't help just yet, the research is still worth the effort.
If you were one of the millions who masked up, washed your hands thoroughly and socially distanced, pat yourself on the back—you may have helped change the course of human history.
Scientists say that thanks to these safety precautions, which were introduced in early 2020 as a way to stop transmission of the novel COVID-19 virus, a strain of influenza has been completely eliminated. This marks the first time in human history that a virus has been wiped out through non-pharmaceutical interventions, such as vaccines.
The flu shot, explained
Influenza viruses type A and B are responsible for the majority of human illnesses and the flu season.
Centers for Disease Control
For more than a decade, flu shots have protected against two types of the influenza virus–type A and type B. While there are four different strains of influenza in existence (A, B, C, and D), only strains A, B, and C are capable of infecting humans, and only A and B cause pandemics. In other words, if you catch the flu during flu season, you’re most likely sick with flu type A or B.
Flu vaccines contain inactivated—or dead—influenza virus. These inactivated viruses can’t cause sickness in humans, but when administered as part of a vaccine, they teach a person’s immune system to recognize and kill those viruses when they’re encountered in the wild.
Each spring, a panel of experts gives a recommendation to the US Food and Drug Administration on which strains of each flu type to include in that year’s flu vaccine, depending on what surveillance data says is circulating and what they believe is likely to cause the most illness during the upcoming flu season. For the past decade, Americans have had access to vaccines that provide protection against two strains of influenza A and two lineages of influenza B, known as the Victoria lineage and the Yamagata lineage. But this year, the seasonal flu shot won’t include the Yamagata strain, because the Yamagata strain is no longer circulating among humans.
How Yamagata Disappeared
Flu surveillance data from the Global Initiative on Sharing All Influenza Data (GISAID) shows that the Yamagata lineage of flu type B has not been sequenced since April 2020.
Nature
Experts believe that the Yamagata lineage had already been in decline before the pandemic hit, likely because the strain was naturally less capable of infecting large numbers of people compared to the other strains. When the COVID-19 pandemic hit, the resulting safety precautions such as social distancing, isolating, hand-washing, and masking were enough to drive the virus into extinction completely.
Because the strain hasn’t been circulating since 2020, the FDA elected to remove the Yamagata strain from the seasonal flu vaccine. This will mark the first time since 2012 that the annual flu shot will be trivalent (three-component) rather than quadrivalent (four-component).
Should I still get the flu shot?
The flu shot will protect against fewer strains this year—but that doesn’t mean we should skip it. Influenza places a substantial health burden on the United States every year, responsible for hundreds of thousands of hospitalizations and tens of thousands of deaths. The flu shot has been shown to prevent millions of illnesses each year (more than six million during the 2022-2023 season). And while it’s still possible to catch the flu after getting the flu shot, studies show that people are far less likely to be hospitalized or die when they’re vaccinated.
Another unexpected benefit of dropping the Yamagata strain from the seasonal vaccine? This will possibly make production of the flu vaccine faster, and enable manufacturers to make more vaccines, helping countries who have a flu vaccine shortage and potentially saving millions more lives.
After his grandmother’s dementia diagnosis, one man invented a snack to keep her healthy and hydrated.
On a visit to his grandmother’s nursing home in 2016, college student Lewis Hornby made a shocking discovery: Dehydration is a common (and dangerous) problem among seniors—especially those that are diagnosed with dementia.
Hornby’s grandmother, Pat, had always had difficulty keeping up her water intake as she got older, a common issue with seniors. As we age, our body composition changes, and we naturally hold less water than younger adults or children, so it’s easier to become dehydrated quickly if those fluids aren’t replenished. What’s more, our thirst signals diminish naturally as we age as well—meaning our body is not as good as it once was in letting us know that we need to rehydrate. This often creates a perfect storm that commonly leads to dehydration. In Pat’s case, her dehydration was so severe she nearly died.
When Lewis Hornby visited his grandmother at her nursing home afterward, he learned that dehydration especially affects people with dementia, as they often don’t feel thirst cues at all, or may not recognize how to use cups correctly. But while dementia patients often don’t remember to drink water, it seemed to Hornby that they had less problem remembering to eat, particularly candy.
Where people with dementia often forget to drink water, they're more likely to pick up a colorful snack, Hornby found. alzheimers.org.uk
Hornby wanted to create a solution for elderly people who struggled keeping their fluid intake up. He spent the next eighteen months researching and designing a solution and securing funding for his project. In 2019, Hornby won a sizable grant from the Alzheimer’s Society, a UK-based care and research charity for people with dementia and their caregivers. Together, through the charity’s Accelerator Program, they created a bite-sized, sugar-free, edible jelly drop that looked and tasted like candy. The candy, called Jelly Drops, contained 95% water and electrolytes—important minerals that are often lost during dehydration. The final product launched in 2020—and was an immediate success. The drops were able to provide extra hydration to the elderly, as well as help keep dementia patients safe, since dehydration commonly leads to confusion, hospitalization, and sometimes even death.
Not only did Jelly Drops quickly become a favorite snack among dementia patients in the UK, but they were able to provide an additional boost of hydration to hospital workers during the pandemic. In NHS coronavirus hospital wards, patients infected with the virus were regularly given Jelly Drops to keep their fluid levels normal—and staff members snacked on them as well, since long shifts and personal protective equipment (PPE) they were required to wear often left them feeling parched.
In April 2022, Jelly Drops launched in the United States. The company continues to donate 1% of its profits to help fund Alzheimer’s research.