Bloomberg: Iceland knows the coronavirus well

The vaccine, considered a turning point in the fight against the pathogen, also relies on some form of long-term antibody reaction in vaccinated people.

But what if immunity declines and all of humanity is plunged into an eternal cycle of relapse? Such a scenario amounts to a nightmare.

Fortunately, the situation may no longer be so dire. So far, only a few confirmed recurrent infections have been reported, suggesting that such cases may be rare. Also, some doctors believe that the symptoms of most relapses will be milder than at the time of the first infection. (This has happened in Hong Kong, but not in the United States). The weakest effect of the virus will depend on the ability of our body to fight it, for example, when so-called T cells are formed.

To assess the risk of reinfection, a fundamental question arises: how many people will develop antibodies and how long will they remain? Some experts worry that only those with the most severe forms of COVID-19 will develop an immune response that is strong enough and long enough to produce the right antibodies. If this is true, the lucky ones who have avoided the most severe symptoms, including most children and young adults, will be more vulnerable to reinfection.

A study of the pandemic in Iceland, published in the New England Journal of Medicine, offers some facts that will allay those fears. The researchers examined serum samples from 30,576 people using six different antibody tests (because different methods often give opposite results).

The study’s main findings show that of the 1,797 people screened who recovered from COVID-19, 91.1 percent developed tangible levels of antibodies. Furthermore, this level did not decrease four months after diagnosis. Older people, who are at higher risk of developing more dangerous forms of coronavirus, and those with the most severe symptoms have developed a stronger immune response.

However, a broader immune response is potentially good news when it comes to the efficacy of any vaccine and seems to confirm that reinfections, at least shortly after the initial illness, can be rare.

While this may in theory be good news for “herd” immunity, it does not mean that we are close to the goal. It is estimated that about 70 percent. antibodies must be formed in the body of the population to effectively stop the spread of the virus. Based on this study, it was found that less than one percent of the Icelandic population had contact with SARS-CoV-2. This figure is much lower than the corresponding figures for Spain, the United Kingdom and Italy, and shows how far many countries are from group immunity.

Also, it is too early to tell if these antibody levels will persist for a longer period of time. In the long run, immunity may wear off and we may be even more vulnerable to the virus. But so far there is no reason to fear the worst case scenario. The vaccine development process is extremely fast, and the available data shows that the human body actually provides some protection. In times of bad news, this news is very welcome.