What is still unknown about Covid-19 after a year

What is still unknown about Covid-19 after a year

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The rate at which we learned about coronavirus is unprecedented and according to scientists we already know a lot.

But one year later, with more than 81 million reported infections and 1.7 million deaths around the world there are still many that we do not know about Covid-19.

The unknowns range from the basics – like how the virus started – to the more complex questions, including how will this pandemic end?

“We have learned an awful lot, but in terms of understanding anything in real detail, we have miles to go,” said Maureen Ferran, associate professor of biology at the Rochester Institute of Technology. “It’s going to keep virologists and public health officials busy for decades.”

Where does the coronavirus come from

While governments were rushing to find a vaccine for the virus, one of the most basic questions dropped from the public’s radar: what is the origin of the virus?

The origin of the virus has been plagued by confusion and conspiracy theories. Initially, the virus appeared to be linked to a Wuhan market selling live animals, but a Lancet study published in January found that one-third of initial patients had no direct connection to the market. .
Some, including US President Donald Trump, have questioned whether the virus was released after it was studied or created in a laboratory in Wuhan. According to scientists, there is overwhelming evidence that the virus originated in nature, and the family members who are closest to coronavirus are too genetically different from Covid-19 to be licked and then caused the outbreak.
Studies have found evidence that the virus spread in the United States and Europe in December 2019, months earlier than first thought. Chinese state media spurred the story that the virus may have originated outside China.

But although Peter Collignon, a professor of microbiology at the Australian National University, says it is likely that the virus spread in the US and parts of Europe before the first cases in those countries diagnosed, there is no conclusive evidence that the virus originated outside China. The World Health Organization, which is investigating the origin of the virus, will investigate whether Covid-19 could circulate in China before the first cases were identified in December.

Despite the plethora of conspiracy theories, there are a few things that most scientists agree on. Covid-19 is a coronavirus, a type of virus that is responsible for everything from colds to SARS. It is zoonotic, meaning it originates from an animal. Some studies point to bats as the likely vectors, known to carry coronaviruses. And most scientists still think that the virus was transmitted to humans in China, because that is where the first cases were identified.

But we still do not know where the virus was first transmitted to humans and whether it was transmitted by another intermediary, such as a pangolin or a cat, before it infected humans. These are questions we may never answer, says Ferran. In the forty years since Ebola was discovered, scientists have not been able to finally say which animal it comes from.

Why it affects some people more than others

When Covid-19 was first identified, it was considered a respiratory disease. But as the months went by, a range of symptoms and complications of the disease became apparent.

Many people lose their sense of smell. Some people vomit or have diarrhea, or get discoloration on their fingers or toes. Some even have impaired cognition or brain damage.
We now know that even those recovering from Covid-19 can experience long-term effects, including anxiety, brain damage and chronic fatigue. In a study published in the British Medical Journal in August, it was found that about 10% of patients suffer from Covid-19 for more than 12 weeks.
But scientists do not know how long these effects of Covid-19 last – and they can not really explain why some people suffer more than others.

A letter published in the journal Annals of Internal Medicine in November describes the case in which two 60-year-old twin brothers were both infected with Covid-19, which had very different results. One twin was discharged from the hospital after two weeks without any complications, the other one was transferred to the intensive care unit and needed a ventilator.

The case showed what researchers have been observing for months: there seems to be almost a randomness in how severely coronavirus affects different people – although there are people who are at higher risk for serious diseases due to pre-existing chronic conditions or age, among other factors.

“We all have slightly different genetics,” Collignon said. “For reasons we do not fully understand, some people can handle infections better than others.”

This is also true in demographics. Scientists have been observing trends for months that show that older people and men tend to be more vulnerable. Scientists know something about why children tend to have less serious coronavirus infections – they have fewer ACE2 receptors in their noses, and these receptors are how coronavirus ends up in our cells. But they can not really explain why older people have such a high mortality rate due to coronavirus – much higher than the usual flu.

“What is it about age that makes you so much more susceptible to disease?” Collignon interviewed. “We have the data and we know it’s true … but I do not think we have all the answers to that.”

How coronavirus is spread

In January, China confirmed that the virus could spread from person to person. But a full year later, there is still debate about exactly how this happens.

Scientists say the most important way the virus spreads is through droplets that are sent into the air when someone coughs or sneezes. These drops fall to one or two feet on the ground, and masks can help disperse them.

But some scientists claim that the virus is also spread by aerosols – much smaller particles that can hang in the air for hours and travel long distances. That would be a problem, says Collignon – cloth masks can not be protected from aerosol transfer.

Collignon says that although aerosol transfer can occur, most infections appear to be caused by droplets. Instead, he thinks much more attention should be paid to the effect of indoor airflow – a recent South Korean study found that virus droplets can still infect people more than two meters away due to airflow from an air-conditioning unit.

There are other questions as well. According to Ferran, it is unclear what dose of coronavirus is needed to infect someone. Children may be more asymptomatic, but there are still no definitive answers as to how many children are involved in the spread of the virus.

All of these questions are important as they have implications for the policy approaches that governments follow. If children are involved in the spread of the virus, it makes sense to close schools – and conversely, if they are not involved in the spread of the virus, closing schools can have a big impact with limited fruit.

How long is someone immune

In August, Hong Kong University researchers said a 33-year-old man was re-infected with Covid-19 – 4.5 months after he was first infected.

This apparently confirms what some people are afraid of – that it is possible to become infected twice.

The good news, according to Collignon, is that while some people can become infected twice, “it’s such a rare occurrence that you get put in a medical journal.” About 99% of people infected with the virus apparently do not get it again at least six months after being infected, Collignon said.

The big question then is how long does the natural immunity against the virus last? Scientists can not answer this yet, as the virus has not been with us long enough.

The same goes for the vaccine – we also do not know how long the immunity lasts for it.

Scientists assumed that the vaccine would provide some form of immunity for a number of years, Collignon said. “But the bottom line is: we do not know yet.”

The coronavirus vaccines currently appear to be more effective than the flu vaccine, which must be administered every year.

Scientists are optimistic about the vaccine and think the chance of long-term side effects is unlikely. As Jonathan Stoye, of the Francis Crick Institute in London, puts it: “I think the risk is much greater because of the virus than the vaccine.”

But that does not mean that there are no questions about the vaccine as long as immunity lasts longer. We do not know if the virus will change, in a way that renders a vaccine ineffective. The longer we take to vaccinate large sections of the population, the more likely it is to mutate, Ferran said. Some of the new vaccines use mRNA technology, which has never been widely used before, which raises questions about whether the immunity to the vaccines will last as long as traditional vaccines.

When the pandemic is over

All of these questions have implications for the big question: when will it all end?

Many worldwide are pinning their hopes on the vaccine, but even that is not an instant solution. It is likely to take years to vaccinate the majority of the world’s population – something that would be needed to stop the spread – and polls show that some people may not be willing to be vaccinated. Even if people do, the vaccine is not a silver bullet.

“I think the vaccines are the right way to go. But it seems like people seeing it will give me 100% protection – no vaccine does,” Collignon said. And even if someone is vaccinated, scientists still do not know if it is possible that they can catch and spread the virus, even if they do not get sick themselves.

It is likely that even if there is widespread vaccination, we will still have to live with the virus. After all, only one virus has been declared extinct in human history. by a vaccine – smallpox.

There are other problems that can affect how long coronavirus is with us, such as whether the virus mutates or develops a new strain. It is possible that the virus may become less deadly or contagious, but it is also possible that the virus may become more virulent. The possibility was highlighted by the British announcement that he had identified a new strain of coronavirus that is 70% more contagious than the old strain.

In the meantime, we will have to rely on a range of other measures. Stoye, of the Francis Crick Institute, said it probably means taking a variety of protections in combination. “You can not say – we will do it one thing, and you will prevent the virus from spreading.”

And this is where all the questions arise about how the virus spreads and how different people are affected. It is important to deal with not only the current outbreak but also future outbreaks.

The problem, Collignon says, is that not enough money is being spent to answer the basics.

“We spend billions of dollars on vaccines and drugs, but you can not get money to do research on the basics like how effective this mask is against the mask,” he said. the problem disappears – they have only reduced the risk.

Stoye said he was concerned that we still had not found the right way to deal with the pandemic.

“That’s what I’m worried about when we talk about future epidemics – will we have learned enough to prevent this one?”

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