A year ago, ophthalmologist Li Wenliang was the first to share information about a SARS-type lung infection with colleagues in Wuhan, China. Researchers have learned a lot since then. Here are the most important points.
Li Wenliang, who gave an early warning on the coronavirus outbreak, later died of COVID-19Image: picture-alliance/AP
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Ophthalmologist Li Wenliang, who worked at the Wuhan Central Hospital, was the first to share information about suspected SARS-type lung infections in the city in Central China on December 30, 2019.
He distributed the news on the social media platform WeChat to colleagues at different hospitals in the city. Police then admonished him for "making false comments on the internet" but an official inquiry later exonerated him.
Li Wenliang died from COVID-19 on February 2.
A novel coronavirus recognized
At the beginning of the second week of January 2020, Chinese authorities made the first public announcement that a new type of virus was rampant in the city of Wuhan.
Now, at the end of December, there have been more than 1.5 million infections in Germany and more than 80 million worldwide.
Here's an overview of what has been discovered about the virus to date, and how far medicine has progressed in the fight against SARS-CoV-2, the novel coronavirus.
Origin of the virus
When the existence of the virus was announced, the first infection of a human by a vertebrate animal had apparently already occurred several weeks earlier.
Initially, Chinese authorities seemed to have tried to suppress any evidence. To this day, it's not exactly clear when and where the virus jumped from animal to human hosts. Transmission from a bat to an intermediate host, perhaps a tanuki — otherwise known as an Asian raccoon dog — and then to humans is considered the likely origin of the pandemic that is still in full swing today.
One of the first images of the novel coronavirus was taken in January 2020Image: picture-alliance/dpa/Center for Disease Control
Decoding the virus
Chinese virologists deciphered the genetic information of the virus in record time. On January 21, they published the genome structure, and three days later they released a detailed description of the virus. This enabled physicians and microbiologists worldwide to begin developing drugs and vaccines.
A typical feature of the virus is the spike proteins (ACE-2) located on its surface. These are crucial for binding to the host cell. That is why a large part of drug and vaccine development has been focused on binding or blocking this protein, or rendering it ineffective in some other way.
A model of the coronavirus: Most prominent is the spike protein (S) that gives the virus its crown-like appearanceImage: picture-alliance/Newscom/CDC
Transmission
In the meantime, a study carried out by virologists in the city of Heinsberg, one of the first hotbeds of the disease in Germany, has established that the virus is particularly prevalent in the throat and lungs. The greatest danger of infection — besides by coming into direct contact with an infected person or touching a contaminated surface, known as smear infections — is through aerosol transmission. The virus can spread particularly well through air-conditioning systems, such as those used widely in the meat industry.
Closed rooms with many people in them are very dangerous. That's why lockdown measures, the closure of entertainment establishments and the cancellation of trade fairs and major events were very effective in containing the disease.
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The largest chains of infection could be traced back to so-called superspreader events.
The use of mouth-and-nose protection, i.e., face masks,has now become established in almost all countries of the world. However, many medical professionals initially questioned whether most people were capable of using masks in everyday life in such a way as to help prevent potential virus transmission.
What is most important is for people to wash their hands, keep their distance from others and air rooms thoroughly.
Even if some pets, such as cats, ferrets and golden hamsters, can become infected by humans, they have not been found to play a significant role in infection chains. However, infections in mink farms in numerous countries have caused great concerns among veterinary doctors. Authorities have subsequently ordered the culling of millions of animals.
Symptoms and risk groups
Initially, it was thought that the new virus was no more dangerous than the seasonal flu. Now, however, physicians know better: The disease poses a threat similar to that of the devastating Spanish flu of 1918. Although many people can get a SARS-CoV-2 infection without symptoms, others become very ill with COVID-19, the disease caused by the virus.
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Some groups of people are more often affected than others: People with previous illnesses, elderly people, people with blood type A and men are more at risk.
Pathologists who have examined COVID-19 victims have been able to confirm that high blood pressure, diabetes, cancer, kidney failure, liver cirrhosis, asthma and cardiovascular diseases are among the most dangerous preexisting conditions. In principle, however, a severe case of the disease can affect anybody, including young people.
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Course of the disease
Mild forms of COVID-19 can present like a cold. Typical symptoms are a sore throat, breathing problems and a loss of sense of smell and taste.
This often leads to sepsis — a frequently fatal overreaction of the immune system that attacks the infected person's own tissue and organs.
The severity of the disease depends, to a large extent, on how strongly a person's immune system reacts to the pathogen.
How to protect yourself against the coronavirus
People around the world are strapping on breathing masks to prevent a viral infection. Other measures are more effective, though. Here are some tips based on WHO guidelines.
Image: Getty Images/X. Chu
Better than nothing
It has not been proven that the face masks seen above can effectively protect you against viral infections. That said, these masks are probably able to catch some germs before they reach your mouth or nose. More importantly, they prevent people from touching their mouth or nose (which most people do instinctually). If you are already sick, such masks may keep you from infecting others.
Image: Getty Images/Stringer
Disinfect your hands
One of the best ways to protect yourself from the virus is to frequently clean your hands, according to the World Health Organization's (WHO) list of recommendations. The WHO recommends alcohol-based hand rub, like the ones seen here in a hospital.
Image: picture-alliance/dpa/S. Pilick
Soap and water will do as well
The simpler day-to-day solution is to use water and soap, if you've got some handy. But make sure to wash your hands thoroughly. Health authorities in the US recommend washing your hands for at least 20 seconds, making sure to pay attention to areas like your fingertips, thumbs and underneath your nails.
Image: picture alliance/dpa/C. Klose
Coughing and sneezing - but doing it right!
So here's what the doctors recommend: When coughing and sneezing, cover your mouth and nose with your flexed elbow. Or use tissue — but then immediately throw that tissue away and wash your hands. With your shirt or sweater, however, no, you don't need to throw them away. Do wash them frequently, though, or take them to the dry cleaner's.
Image: Fotolia/Brenda Carson
Stay away!
Another recommendation that may not work for everybody: Avoid close contact with anyone who has fever and cough! If you have to tend to sick people, make doubly sure to take additional protective measures.
Image: picture alliance/empics
Got a fever? Go to the doctor, not on a trip!
If you have fever, cough and difficulty breathing, seek medical care early. Avoid public places so you don't infect others. And also, explain to your doctor where you've previously traveled and who you may have come in contact with.
Image: Reuters/P. Mikheyev
Avoid contact!
When visiting live markets in areas currently experiencing cases of the novel coronavirus, avoid direct unprotected contact with live animals. That includes any surfaces that are in contact with animals as well.
Image: DW
Well done — not rare!
Cook meat thoroughly. The consumption of raw, or undercooked, animal products should be avoided. Raw meat, milk or animal organs should be handled with care to avoid cross-contamination with uncooked foods. These are good food safety practices and help prevent the spread of illnesses.
Image: picture-alliance/Ch. Mohr
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Treatment
At the beginning of the pandemic, many patients with severe courses of the disease received artificial respiration (intubation) at an early stage and died all the same.
Now, however, physicians working in intensive care units have moved away from standard ventilation, because lung specialists have stressed that artificial respiration under positive pressure can do more damage than good to the lungs.
As long as patients are able to breathe on their own, they now receive oxygen without being connected to a respirator. Intubation is used as an option only in an extreme emergency.
In many cases, when the kidneys are severely damaged by COVID-19, dialysis is also necessary. Intensive care units are now also taking other damaged organs into account.
The healing process can be accelerated in specialized clinics by the administration of antibodies from the blood of cured COVID-19 patients. These antibodies take up the fight against the virus in the body of the patient who receives the donated blood.
As a rule, COVID-19 patients must undergo lengthy, individually tailored rehabilitation measures after their medical treatment. These must also take into account their specific previous illnesses and possible organ damage.
What is remdesivir?
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No convincing drugs yet
Remdesivir is one of the few pharmaceutical drugs that have been shown to shorten the course of the disease. This is why it was hotly contested on the market.
But it is not a miracle cure. It shortens the healing process by a few days in patients who receive oxygen, but it does not improve their chances of survival. Meanwhile, the World Health Organization has advised against remdesivir for hospitalized COVID-19 patients.
The efficacy and safety of the first has not yet been conclusively proven, while hydroxychloroquine has been shown to be ineffective and may even be dangerous.
On December 18, 2020 the WHO stated, that "corticosteroids (such as dexamethasone) are the only class of medicines to demonstrate some benefits", adding that "for patients with mild or moderate disease, finding effective, safe, affordable and accessible therapeutics to reduce mortality and morbidity remains an urgent priority."
Russia and China have also authorized vaccines, respectively. Both countries are also exporting those into numerous third countries.
Mass production and launching effective vaccination campaigns is the main challenge for the pharmaceutical industry and health authorities. Gene-based RNA vaccines, which can be produced relatively quickly, have an advantage here.
However, experts are expecting that vaccination campaigns are unlikely to finish before 2022.
More in the pipeline
At least 233 vaccine projects have been launched worldwide (as of December 22, 2020) according the World Health Organization and 246 according to the German research pharmaceutical companies. These are essentially divided into three vaccine types: attenuated vaccines, inactivated vaccines and gene-based RNA vaccines.
In the latter case, however, physicians have been entering uncharted territory because no such approved vaccines have been available in the past. Both the BioNTech-Pfizer and the Moderna vaccines are such RNA vaccines. The former has approval in both the EU and US, while the latter has so far been approved only in the US and is expecting approval in the EU in early January.
And on December 30, British regulators approved the AstraZeneca vaccine designed by scientists at the University of Oxford. It is not an mRNA vaccine, but an attenuated vector vaccine, in which a harmless chimpanzee cold-virus serves to transport parts of SARS-CoV-2 proteins, that trigger an immune response.
In addition, there is a tuberculosis vaccine that has already been approved. This does not directly target SARS-CoV-2 but strengthens basic innate immunity. Researchers at the Max Planck Institute for Infection Biology in Berlin are currently trying to improve this vaccine genetically.
Hands off! What can we touch during the coronavirus outbreak?
If you find yourself suspiciously staring at your pets, your potatoes and even those birthday cards on the mantelpiece, you aren't alone. Coronavirus is seemingly everywhere. What's safe to touch? Here are some answers.
Image: picture-alliance/Kontrolab/IPA/S. Laporta
Contaminated door handles
Current research says the coronavirus family of viruses can survive on some surfaces, like door handles, for an average of four to five days. Like all droplet infections, SARS-CoV-2 can spread via hands and frequently touched surfaces. Although it hasn't previously been seen in humans and therefore hasn't been studied in detail, experts believe it spreads similarly to other known coronaviruses.
A certain degree of caution is called for when eating lunch at your work cafeteria or in a cafe — that is, if they haven't been closed yet. Technically, coronaviruses can contaminate cutlery or crockery if they're coughed on by an infected person. But the German Federal Institute for Risk Assessment (BfR) states that "no infections with SARS-CoV-2 via this transmission route are known to date."
Image: picture-alliance/dpa/J. Kalaene
Virus-carrying teddy bears?
Should parents fear a possible infection from imported toys? It's unlikely, say the BfR. As of yet, there are no cases of an infection via imported toys or other goods. Initial laboratory tests show that the pathogens can remain infectious for up to 24 hours on cardboard and up to three days on plastic and stainless steel - especially in high humidity and cold settings.
Image: picture-alliance/dpa/S. Gollnow
Packages, letters and shipped goods
A recent study from the Rocky Mountain Laboratories in the US found the novel coronavirus can survive up to 72 hours on stainless steel and up to 24 hours on cardboard surfaces — in an ideal laboratory setting. But because the survival of the virus is dependent on many factors like temperature and humidity, the BfR says getting infected from handling the post is "rather unlikely."
Image: picture-alliance/dpa/T. Weller
Can my dog infect me, or can I infect my dog?
Experts consider the risk of pets being infected with the coronavirus to be very low. But they can't yet rule it out. The animals themselves show no symptoms, so they don't become ill. However, if they are infected, it is possible they could transmit coronaviruses via the air or via excretions (their poop).
Image: picture-alliance/dpa/AP/A. Tarantino
Fruit and vegetables: suddenly dangerous?
"Unlikely." According to the BfR, transmitting SARS-CoV-2 via contaminated food is not likely to happen and, so far, there are no proven cases of infection this way. As the viruses are heat-sensitive, heating food during cooking can further reduce the risk of infection. Of course, you should thoroughly wash your hands before cooking and eating — and this goes for anytime, regardless of corona!
Image: picture-alliance/Kontrolab/IPA/S. Laporta
Contaminated frozen food
Although the SARS and MERS coronaviruses known to date don't like heat, they are quite immune to the cold. Research shows they can remain infectious at minus 20 degrees Celsius for up to two years. But the BfR gives frozen food the all-clear. So far, there's no evidence of SARS-CoV-2 infection via the consumption of any food, including frozen food.
Image: picture-alliance /imageBROKER/J. Tack
But leave those wild animals alone!
The COVID-19 outbreak has prompted many extraordinary measures and China's ban of the consumption of wild animals is no exception. There is compelling research to suggest the novel coronavirus originated in bats before being passed to humans via another intermediate animal. But it's not the animals we need to blame — experts say humans are exposed to these viruses via our interaction with animals.
Image: picture-alliance/Photoshot/H. Huan
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When does herd immunity occur?
It's true that more and more people are becoming infected worldwide. By the end of December, more than 80 million people will have contracted the virus. However, with a population of 7.8 billion, the world is still a long way from achieving any effective degree of immunity to the disease.
In addition, it's unclear whether recovered patients remain permanently immune to the virus. A serological blood test can determine whether someone is carrying antibodies against the virus. A polymerase chain reaction (PCR) test taken with a cotton swab can make it clear whether someone is acutely ill and contagious.
This article has been updated since its original publication.
Dogs and cats can also be infected with coronavirus
Dogs and cats frequently become infected when their owners suffer from COVID-19. They oftentimes show symptoms, but the disease is usually mild.
Image: DW/F. Schmidt
Better keep your distance in case of COVID
That's how to do it: If humans have COVID-19, dogs had better cuddle with their stuffed animals. Researchers from Utrecht in the Netherlands took nasal swabs and blood samples from 48 cats and 54 dogs in 2021 whose owners had contracted COVID-19 in the last 200 days. Lo and behold, they found the virus in 17.4% of cases. Of the animals, 4.2% also showed symptoms.
Image: Fabian Schmidt/DW
Animals can get sick, too
About a quarter of the animals that had been infected were also sick. Although the course of the illness was mild in most of the animals, three were considered to be severe. Nevertheless, medical experts are not very concerned. They say pets do not play an important role in the pandemic. The biggest risk is human-to-human transmission.
Image: Fabian Schmidt
To pet, or not to pet?
The fact that cats can become infected with coronaviruses has been known since March 2020. At that time, the Veterinary Research Institute in Harbin, China, had shown for the first time that the novel coronavirus can replicate in cats. The house tigers can also pass on the virus to other felines, but not very easily, said veterinarian Hualan Chen at the time.
Image: picture-alliance/dpa/K-W. Friedrich
Don't worry
But cat owners shouldn't panic. Felines quickly form antibodies to the virus, so they aren't contagious for very long. Anyone who is acutely ill with COVID-19 should temporarily restrict outdoor access for domestic cats. Healthy people should wash their hands thoroughly after petting strange animals.
Image: picture-alliance/imageBroker
Who's infecting whom?
Should this pet pig keep a safe distance from the dog when walking in Rome? That question may now also have to be reassessed. Pigs hardly come into question as carriers of the coronavirus, the Harbin veterinarians argued in 2020. But at that time they had also cleared dogs of suspicion. Does that still apply?
Image: Reuters/A. Lingria
When humans are a threat
Nadia, a four-year-old Malaysian tiger, was one of the first big cats to be detected with the virus in 2020 — at a New York zoo. "It is, to our knowledge, the first time a wild animal has contracted COVID-19 from a human," the zoo's chief veterinarian told National Geographic magazine.
Image: Reuters/WCS
COVID hits zoos again
In early December 2021, two hippos at Antwerp Zoo in Belgium tested positive for coronavirus. Both animals, mother Hermien and daughter Imani, had a cold. Otherwise, they were doing well. The zoo had to close temporarily and quarantine the hippos.
Image: alimdi/imago images
Have bats been wrongly accused?
It is thought that the virus originated in the wild. So far, bats are considered the most likely first carriers of SARS-CoV-2. However, veterinarians assume there must have been another species as an intermediate host between them and humans in Wuhan, China, in December 2019. Only which species this could be is unclear.
This racoon dog is a known carrier of the SARS viruses. German virologist Christian Drosten spoke about the species being a potential virus carrier. "Racoon dogs are trapped on a large scale in China or bred on farms for their fur," he said. For Drosten, the racoon dog is clearly the prime suspect.
Image: picture-alliance/ImageBroker/C. Krutz
Or perhaps this little suspect?
Pangolins are also under suspicion for transmitting the virus. Researchers from Hong Kong, China and Australia have detected a virus in a Malaysian Pangolin that shows stunning similarities to SARS-CoV-2.
Image: Reuters/Kham
Quarantine for ferrets
Hualan Chen also experimented with ferrets. The result: SARS-CoV-2 can multiply in the scratchy martens in the same way as in cats. Transmission between animals occurs as droplet infections. At the end of 2020, tens of thousands of martens had to be killed in various fur farms worldwide because the animals had become infected with SARS-CoV-2.
Experts have given the all-clear for people who handle poultry, such as this trader in Wuhan, China, where scientists believe the first case of the virus emerged in 2019. Humans have nothing to worry about, as chickens are practically immune to the SARS-CoV-2 virus, as are ducks and other bird species.
