Does the covid-19 variant require a new vaccine?
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(CNN) ––
When China first reported coronavirus cases to the World Health Organization (WHO) on December 31, 2019, it described them as a mysterious new strain of pneumonia.
It didn't even have a name.
After two weeks, the Chinese scientists identified the sequence of the virus genome, that is, the genetic code that makes it up.
Within three weeks, the first screening test kits were created and then shared by WHO.
And shortly after 11 months since the initial cases of the virus were reported, the first people were vaccinated to fight it.
Which made the covid-19 vaccines the fastest ever developed.
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The speed at which we have learned about the coronavirus is unprecedented.
And scientists say we already know enough.
But a year later, with more than 81 million reported cases and 1.7 million deaths worldwide, there is still a lot we don't know about covid-19.
Those unknowns range from the basics - such as how the virus started - to more complicated questions, such as how this pandemic will end.
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“We have learned a tremendous amount.
But in terms of understanding anything in real detail, we still have miles and miles to go, ”said Maureen Ferran, associate professor of biology at the Rochester Institute of Technology.
"This will keep virologists and public health officials busy for decades."
Where did the coronavirus originate?
As governments scrambled to find a vaccine against the virus, one of the most basic questions disappeared from the public's radar.
What is the origin of the virus?
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The origin of the virus has been plagued with confusion and conspiracy theories.
At first, the coronavirus appeared to be linked to a Wuhan market that sold live animals.
However, a Lancet study published in January found that a third of initial patients had no direct connection to that market.
Some, including US President Donald Trump, questioned whether the virus was released after being studied or created in a Wuhan laboratory.
Scientists say there is overwhelming evidence that the virus originated in an animal.
And they indicate that the closest known relatives of the coronavirus are too different genetically for COVID-19 to have leaked out and subsequently caused the outbreak.
Studies have uncovered evidence that the virus may have circulated in the United States and Europe in December 2019, months earlier than previously thought.
For its part, Chinese state media have promoted the narrative that the virus may have originated outside of China.
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In this regard, Peter Collignon, professor of microbiology at the Australian National University, said that it is quite likely that the virus circulated in the United States and parts of Europe before the first cases were diagnosed in those countries.
However, he clarified that there is nothing conclusive to show that the virus originated outside of China.
The World Health Organization investigates the origin of the virus.
In that sense, it will analyze whether the covid-19 could have circulated in China before the first cases were identified in December.
Despite the large number of conspiracy theories, there is some data that most scientists agree on.
Covid-19 is a coronavirus, a type of virus that is responsible for everything from the common cold to SARS.
Also zoonotic, which means it originally came from an animal.
Some studies point to bats as possible vectors, as these animals are known to carry coronavirus.
Additionally, most scientists still believe that the virus was transferred to humans in China, as that is where the first cases were identified.
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But we still don't know where the virus was first transmitted to humans.
Nor was it through another intermediary animal, such as a pangolin or a civet, before infecting humans.
Those are questions we may never answer, Ferran said.
After all, in the more than 40 years since Ebola was discovered, scientists have not been able to definitively answer which animal it came from.
Why does the coronavirus affect some people more than others?
When COVID-19 was first identified, it was considered a respiratory disease.
But as the months passed, a variety of symptoms and complications of the disease became apparent.
Many people lose their sense of smell.
Some vomit or have diarrhea, or have discolored fingers or toes.
Others even have cognitive impairment or brain damage.
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We now know that even those recovering from COVID-19 can experience long-term effects, such as anxiety, brain damage, and chronic fatigue.
A study published in the British Medical Journal in August found that around 10% of patients had a prolonged illness from COVID-19 lasting more than 12 weeks.
But scientists do not know how far these effects of covid-19 can be spread.
And they can't really explain why some people suffer more than others.
A letter published in the Annals of Internal Medicine in November described a case in which two 60-year-old twins with Covid-19 had very different results.
A twin was discharged from the hospital after two weeks without complications.
Meanwhile, the other was transferred to intensive care and required an artificial respirator.
The case demonstrated what researchers have observed for months.
There seems to be almost randomness in the severity with which coronavirus affects different people.
Although, there are some people who are at higher risk for existing chronic severe disease conditions or old age among other factors.
"We all have slightly different genetics," Collignon explained.
"Often times, for reasons we don't fully understand, some people cope with infections better than others," he said.
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That is also true of demographics.
For months, scientists have watched trends showing that older people and men tend to be more vulnerable.
Scientists already know something about why children tend to have less severe coronavirus infections.
They have fewer ACE2 receptors in the nose, and these receptors are the way the coronavirus enters our cells.
But they can't really explain why older people have such a high death rate from covid-19, much higher than from the common flu.
"What is your age that makes you so much more susceptible to disease?" Asked Collignon.
"We have the data and we know it's true ... but I don't think we have all the answers for that," he added.
How is the coronavirus transmitted?
In January, China confirmed that the virus could spread from person to person.
But a year later, there is still a debate about how exactly contagion happens.
Scientists say the key way the virus spreads is through droplets left in the air when someone coughs or sneezes.
These drops fall to the ground after one or two meters.
And masks can help prevent its spread.
However, some scientists argue that the virus is also spread by aerosols.
That is, much smaller particles that can remain suspended in the air for hours and travel long distances.
That would be a problem, Collignon said: Cloth masks cannot protect against the transmission of aerosols.
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Collignon noted that while aerosol transmission could occur, it appears that most infections are caused by droplets.
Now, he believes that much more attention should be paid to the effect of airflow indoors.
A recent study from South Korea found that virus droplets could infect people more than two meters away due to the flow of air from an air conditioning unit.
There are other questions too.
According to Ferran, the dose of coronavirus that is needed for someone to become infected is not clear.
Children are more likely to be asymptomatic.
But, there are no definitive answers yet on how much children play in spreading the virus.
All of these questions are important as they have implications for the policy approaches that governments take.
If children have a role in spreading the virus, then it makes sense to close schools.
And conversely, if they are not involved in spreading the virus, closing schools could have a huge impact with limited profitability.
How long is someone immune?
In August, researchers from the University of Hong Kong said that a 33-year-old man had been reinfected with COVID-19, 4.5 months after the first infection.
That seemed to confirm what some people feared: that it was possible to get infected twice.
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But there is good news, according to Collignon.
While some people can get infected twice, "it's such a rare event that they put you in a medical journal," he said.
About 99% of people infected with the virus do not appear to contract it again for at least six months after being infected, Collignon said.
The big question, then, is how long does natural immunity against the virus last?
Scientists can't answer that yet, as the virus hasn't been with us long enough.
The same goes for the vaccine.
We also don't know how long immunity lasts.
The scientists assumed that the vaccine would provide some form of immunity for several years, Collignon said.
"But the bottom line is that we don't know yet."
At the moment, the coronavirus vaccines appear to be more effective than the influenza vaccine, which must be administered every year.
Scientists are optimistic about the vaccine and believe long-term side effects are unlikely.
As Jonathan Stoye of the Francis Crick Institute in London says: "I think the risk is much higher from the virus than from the vaccine."
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But that doesn't mean there are still no questions about the vaccine beyond how long immunity lasts.
We do not know if the virus will mutate, in a way that the vaccine is ineffective.
The longer we take to vaccinate large sectors of the population, the more opportunities the coronavirus has to mutate, Ferran said.
And some of the new vaccines use mRNA technology, which has never been widely used before.
Which raises questions about whether the immunity of those vaccines will last as long as traditional vaccines.
When will the pandemic end?
All of these questions have implications for the big question: when will this all end?
Many around the world are pinning their hopes on the vaccine, but even that is not a quick fix.
Vaccinating the majority of the world's population is likely to take years.
Something that would be necessary to stop the spread.
And surveys show that some people may not be willing to get vaccinated.
Even if people do, the vaccine is not a silver bullet.
“I think vaccines are the way to go.
But people seem to have an opinion that it will give me 100% protection.
No vaccine does that, ”said Collignon.
Even if someone is vaccinated, scientists still do not know if it is possible for them to contract the virus and spread it.
Even though they themselves don't get sick.
It is likely that even when there is widespread vaccination, we still have to live with the virus.
After all, only one virus in human history has been declared eradicated by a vaccine: smallpox.
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There are other issues that could influence the duration of the coronavirus, such as whether the virus mutates or develops a new strain.
The virus may become less deadly or infectious.
But it is also possible that it is more virulent.
That possibility has been highlighted by the recent announcement from the UK that it has identified a new strain of coronavirus that appears to be 70% more infectious than the previous strain.
In the meantime, we will have to rely on a number of other measures.
Stoye of the Francis Crick Institute said that would likely mean combining a variety of different protections.
"You cannot say: we will do one thing and it will prevent the virus from spreading."
And that's where all the questions come in about how the virus spreads and how different people are affected.
They are important not only for dealing with the current outbreak, but also for future outbreaks.
The problem, Collignon argued, is that not enough money is spent answering the basic questions.
“We spend billions of dollars on vaccines and medicines.
But you cannot get funds to research basic aspects such as how effective this mask is compared to another, "he said.
And he added that was partly because the answers to those questions don't make the problem go away, they just reduce risk.
Stoye said she was concerned that we still hadn't found the right way to deal with the pandemic.
"That is what worries me when we talk about future epidemics: have we learned enough from this one to prevent another?"
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