Covid, 2 years later: 5 things we've discovered since the start of the pandemic
It's been two years since a new coronavirus was discovered after an outbreak in China.
The country announced the discovery of Sars-Cov-2, which causes covid-19, on December 31, 2019, and since then, the world has changed at breakneck speed. The ensuing pandemic has changed from the way we work to the medical treatments available to us.
Here are five things we've learned since the beginning of the pandemic.
Before the pandemic, vaccine development took at least 4 years
1. mRNA vaccines work and can be made quickly
Once covid-19 reached pandemic status, a race began among researchers to make a vaccine that could protect the population.The bet paid off. Using mRNA, not only was Pfizer/BioNTech (and later Moderna) able to develop a covid-19 vaccine faster than any other company, it also opened the door to a host of new treatments using similar technology.
The process works by taking a small piece of genetic code, called mRNA, and coating it in fat. This material can then be taken up by cells, which use it as a set of instructions to produce new material.
In coronavirus vaccines, mRNA instructs our cells to create a small part of the covid virus. The body's immune system then learns to recognize the virus and is ready to attack you if your body has been infected.
But mRNA has the potential to be used in many other ways. In addition to being used to create new vaccines for diseases like HIV, flu and Zika, it can be used to train the body's immune system to attack cancer cells, to create the proteins that are missing in the cells of people with cystic fibrosis, or to teach the body's defense system in people with multiple sclerosis to stop attacking the nervous system.
Research into mRNA treatments has been going on for decades, but covid-19 vaccines are the first time the technology has been proven to work in practice. This success could spur research with the potential to change the lives of millions of people.
The pandemic affected the poorest most strongly
2. Covid-19 spreads through the air much more easily than we initially thought
About four months after the start of the pandemic, the World Health Organization still did not advise people to wear masks. "We don't recommend wearing masks unless you are sick," said Maria Van Kerkhove, technical leader of the covid-19 fight at the organization.
But the scientific evidence that has emerged since then has changed that view. Today, as during most of the pandemic, the WHO says that people should "make mask wearing a normal part of being around other people".
Researchers have found that the covid-19 virus is transmitted not just by large drops of saliva or mucus that are in the air for a short time after someone coughs or sneezes.
The virus can also be spread through aerosols - much smaller particles that can stay in the air for much longer.
We now know that covid-19 is mainly transmitted by air. Transmission of Sars-CoV-2 after touching surfaces is now considered relatively minimal.
"In March [2020], people asked me how much time they needed to spend cleaning up groceries. Everyone was hypervigilant and hyperparanoid," says Paula Cannon, professor of Microbiology and Molecular Immunology at the University of Southern California School of Medicine.
"Since then, we've learned that airborne virus in poorly ventilated indoor spaces is the likely cause of most transmissions and the reason why bars and indoor environments are so risky," he explains.
The virus is emitted by people without a mask while talking, singing or simply breathing and remains in the air if the room is not ventilated.
Washing hands and cleaning surfaces are still good habits, but there is now much more emphasis on mask wear and ventilation.
Working from home has become much more common
3. Homework is here to stay
Millions of people around the world started working from home instead of going to offices and other workplaces during the pandemic.
The pandemic showed that this type of work does not reduce productivity and made many companies abandon their resistance to adopting it.
Twitter announced in May 2020 that its employees could work from home full-time even after the pandemic ends, as long as their role allows them to do that work.
"The last few months have proven that we can do this job," the company said.
Facebook made a similar announcement earlier this year, but it's not just the tech giants looking to make the switch.
A survey of 1,200 companies by Enterprise Technology Research showed that the percentage of workers worldwide who are permanently working from home is expected to double by 2021.
In a global survey of more than 200,000 people in 190 countries, Boston Consulting found that 89% of people expected to be able to work from home at least a few times a week after the pandemic ended. This is a considerable increase from the rate before the pandemic: only 31% of people had this desire.
But for many people, often with less secure and less-paid jobs, flexible working opportunities may be more limited. This could further increase inequalities in society.
Today we know that the virus is transmitted mainly by air.
4. The pandemic has hit people in situations of social vulnerability the most
The covid-19 pandemic reminded us that a crisis could worsen the enormous social inequality that already exists in the world.
In the United Kingdom, a study by researchers at the UK Biobank found that in the poorest part of the country 11.4% of people contracted covid, while in the more privileged areas the rate was lower (7.8%).
The team also found that people from ethnic minorities were disproportionately affected, something that also happened in the United States.
In New York, 2020 data showed that Hispanics and blacks accounted for 34% and 28% of covid deaths, respectively, although they make up 29% and 22% of the population.
A survey in California showed that non-Hispanic black patients were 2.7 times more likely to be hospitalized compared to non-Hispanic white patients.
In many countries there is no accurate data on the effects of covid, but globally one of the biggest disparities is in vaccination rates. In high- and middle-income countries, about 70% of people are fully vaccinated, according to data from Our World in Data. This drops to just 4% in low-income countries. Even in lower middle-income countries, the rate is still only 32%.
As medical authorities distribute booster doses and the omicron variant spreads around the world, the consequences of slow vaccine deployment in less-developed countries could become even more deadly.
The pandemic killed millions before vaccines were developed
5. We are not sure how, or if, the covid-19 pandemic will end
In many diseases, such as smallpox, it is possible to achieve herd immunity in the population through massive population vaccination - that is, the number of people immunized is so high that the virus cannot circulate.
For other illnesses, such as the flu, this is more difficult to achieve because of the constant mutations of the viruses or the diminishing response of the immune system over time.
In the case of covid-19, the development of the pandemic increasingly shows that we may be facing the second case. The decrease in the immune system's response over time is even the reason why many countries (including Brazil) are implementing vaccine booster programs.
According to Shabir A Madhi, a professor at the University of the Witwatersrand in South Africa, the immune response after infection or vaccination against covid-19 lasts approximately six to nine months.
While vaccines are effective in protecting against the more serious consequences of covid, even the best ones don't seem to stop people from passing the virus on to others.
"With the vaccines we have, even if they reduce transmission, the concept of herd immunity makes no sense", says Salvador Peiró, from the FISABIO research institute in Valencia, Spain.
And Sars-CoV-2 has undergone rapid mutations that generate new variants - some more transmissible and may be more resistant to the effect of vaccines.
Variants also show that we will have to "live with" the virus as it evolves, updating vaccines regularly to adapt. In this scenario, countries with a high rate of vaccination will return to more or less normal lives, knowing that while some people will get sick, the health systems will not be overburdened.
Meanwhile, a small number of territories with low levels of covid, such as New Zealand and Hong Kong, face a dilemma. With no sign that covid has been eradicated around the world, they will either have to continue with strict quarantine and travel restrictions or face the day when they relax measures to allow more covid in.
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