Children can be infected with SARS-CoV-2, but it affects them much less ¹⁹. The reasons could be that (i) children get fewer SARS-CoV-2 viruses, or (ii) that their immune system is more efficient. The first hypothesis loses weight knowing that the goals in which the virus hits us, ACE2 receptors, are also present in children. But there are conflicting results, and the possibility of children becoming less infected cannot be ruled out today.

Global data in different parts of the world indicate that adults are two to three times more likely to contract COVID-19 than children ²⁰ but most of this data comes from tests carried out on symptomatic people, and children could be carriers without symptoms. Therefore, the best studies are those that carry out the tests «blindly» on a random population without the need for individuals to be symptomatic.

In Iceland, that country of 338,000 inhabitants that brilliantly qualified for the World Cup in Russia, a population of 12,323 people was randomly tested. None of the 848 children tested under the age of 10 tested positives, while 100 adults carried the SARS-CoV-2 ²¹. And this is not because Icelanders refrain from kissing their children, as Arnor Gudjhonsen tenderly demonstrated when he was replaced by his son Eidur in an international match against Estonia.

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The other advantage that children may have is their immune system, which may be more efficient in avoiding COVID-19 infection. Moreover, lacking the complexity of adult immune systems, they seem to avoid complex immune reactions that cause complications and deaths from COVID-19. This protection of children against viruses that affect adults has already been seen for other viral diseases such as mononucleosis, caused by the Epstein-Barr Virus (EBV), which does not produce symptoms in infected children ²².

Therefore, in the context of COVID-19, it seems that the younger your immune system; the better. Age is also relevant in football, especially in categories under 17, (U-17, U-15, etc). In these competitions, countries have been known to field older players. In 1989, Nigeria was banned from competing in junior international competitions for two years after selecting over-age players. In 2016, in a U-17 tournament, an investigation into Zambia’s selection was launched after one of its players dedicated a goal to his wife and three children. Zambia ended up being thrown out of the competition. Such cheating is not only confined to African countries. Especially innovative was the Ecuadorian Ángel Cheme who pretended to be Gonzalo Chila, a boy three years younger. A «vivarachería», according to a local newspaper. The vivacious and dishonest people of the world have had a problem called magnetic resonance imaging. Using this technique, the age of a child can be known by resonating their bone structures, and it is 99% reliable in children up to 17 years of age. Guinea was disqualified from the 2019 U-17 Africa Cup because the MRI said that Aboubacar Conte and Tidiane Keita were over 17 years old.

In this case, science, through magnetic resonance imaging, allows us to know the age of children, but we still have to wait to be able to accurately determine the capacity of children to infect and be infected. Data from the child in the Alps, Iceland and Veneto * are not enough. We need to generate more knowledge so that, if we see a child approaching, although we know they play as defenders, we can distinguish whether he/she is like the scorer Ronald Koeman, or Javier Mascherano, who scored his first goal with FC Barcelona because they let him take a penalty after seven years (319 games ) without getting on the scoresheet.

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