In which patients is convalescent plasma used? 27:14

(CNN Spanish) – It has already been officially 6 months since the coronavirus arrived and gave a turnaround to the normality of our planet.

Although we know a lot of data on the disease, it is still a mystery what the real number of infections is, we do not know science when and where the pandemic started and scientists are still investigating why there is a disparity of intensity of symptoms in the patients . Dr. Elmer Huerta develops in this episode the 6 enigmas of the disease.

Hello, I am Dr. Elmer Huerta and this is your daily dose of information about the new coronavirus, information that we hope will be useful to take care of your health and that of your family. Today we will see what mysteries persist about covid-19 six months after the disease appeared.

At the time of writing this episode, exactly 6 months ago, Chinese officials announced that 27 cases of a rare disease, characterized by severe pneumonia, had been discovered, and that seven of those infected were very ill.

Who would have thought that this small outbreak – associated with workers in the Wuhan Live Wild Animals Market – was going to become the great pandemic of this century? A pandemic that to date has caused more than 10 and a half million cases and more than half a million deaths worldwide.

A recent New York Times article gave a synopsis of the six mysteries that still surround the disease, six months after it appeared, and today we will make a brief summary.

The first is about the true number of people who have been infected in the world.

This is a very difficult amount to calculate, and obviously depends on the number of tests and the progress of the virus in a region. There are no official figures in this regard in the United States. Some analysts venture that between 10 and 20 million people may have been infected with the new coronavirus. Even the director of the Centers for Disease Control and Prevention has said that the country has only counted about 10% of coronavirus infections.

On the other hand, in Spain, an antibody study suggests that 5% of the population was infected, and that in Madrid, one of the most affected cities in the country, the number rises to 11.3%.

Similarly, in France, only 4.4% of the general population would have been infected, having found that in more heavily hit areas, such as Paris, the number rises to between 9 and 10%, according to a study published by the American Association for the Advancement of Science.

In England, according to the chief scientific adviser, Sir Patrick Vallance, only 4% of Britons tested positive, reaching 10% in London.

Knowing that for every reported case, there may be 10 other infections, those numbers are highly uncertain.

The second mystery is the amount of virus or viral load that is necessary to get infected and get sick.

That number is unknown for the new coronavirus, although some researchers suspect that the viral load needed to cause disease may be low.

Knowing this so-called ‘viral load’ is important to determine with certainty the risk of infections by touching contaminated objects, for example, or to know – as suspected – that infections caused by a large viral load are more severe than those caused by lower viral loads.

The third, and a topic that we have already developed in previous episodes, is knowing why, when faced with the same virus, some people get sick much more than others.

Using a scientific discipline called proteomics, a study published in Cell Press is investigating whether the finding of 22 blood proteins found in very sick patients could help predict the risk of a person affected by the virus.

Another line of research concerns the genetic differences of people. A recent study published in The New England Journal of Medicine, has found, for example, that between 1,980 Spanish and Italian patients affected by covid-19, two genes were identified that made them more susceptible to respiratory complications during their hospitalization.

The fourth is the role that children play in the spread of the disease.

This is another great mystery, it is not known if children are not infected as frequently, or if they are infected but they are mostly asymptomatic. Knowing that children can infect, knowing this information is very important to determine their contribution to contagion from adults.

The fifth mystery is knowing when and where this pandemic started.

Studies indicate that the new coronavirus would have originated from a bat in China, estimating that the first case of the infection associated with the Wuhan market occurred in a person who presented his first symptoms on December 1, 2019, and was hospitalized on December 16. This would indicate that in November it was already infected.

On the other hand, in multiple countries it has been verified that the virus was already circulating for a few weeks before the official announcements of the first cases were made.

All this indicates that in a world as globalized as the one we live in, it is possible that the cases may have simultaneously left China and epidemics have started at the same time in Europe, the United States and other countries.

And the sixth mystery is to know if a person who already had the disease will have permanent immunity.

This is a very tricky issue because it will not only affect the behavior of people who were already affected when the restrictions were lifted, but it will also determine the protection time that a vaccine can give us.

So far, unfortunately, we are not sure if immunity is permanent. Six months is too little time to tell if covid-19 is a disease that can happen again.

Send me your questions on Twitter, we will try to answer them in our next episodes. You can find me at @DrHuerta.

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If you have any questions, you can send them to Dr. Elmer Huerta on Twitter. You can also go to for all the episodes of our podcast “Coronavirus: Reality vs. fiction”.