At present, the world is under the spell of a new influenza virus, Covid-19. One region after another goes into complete lockdown; in particular to prevent the virus to spread with such speed that hospitals would be overburdened. The virus is particularly contagious as this viral species is new; people have not yet had the opportunity to develop a resistance to it. Also because people may be contagious in the incubation period, when they themselves are still free of symptoms. The outbreak may even have deteriorated because of an overresponse of patients’ immune systems, that can have fatal consqeuences.

Covid-19. Source: health.mil

Control is difficult

In the Annals of Internal Medicine researchers investigated the incubation period, the period between contagion and the outbreak of symptoms. On average people infected with Covid-19 show symptoms after a five-day period. But this can vary between two and twelve days. There appear to be major differences among people, like with other corona infections like SARS and MERS. And there are some indications that people may also be contagious during this incubation period; and possibly people who are ill but do not have symptoms could transfer Covid-19 as well. Of course, this is a major obstacle in the effective control of the disease.

Covid-19 manifests itself in effects like fever and coughing. Often, people recover all by themselves. But the virus seems to be dangerous especially to elderly people or people with a health condition. Therefore, authorities often advise against contacts between young children (who can be infected, not showing any symptoms) and such people. Critical research from China now suggests that patients could also die from Covid-19 through an overreaction of their own immune systems, the so-called cytokine storm. Such an overreaction could destroy healthy lung tissue, leading to acute difficulty in breathing and multi-organ failure. If untreated, cytokine storms tend to be fatal. Doctors could treat them with immunosuppressive agents – but that may appear to be too risky with very ill patients. Fortunately, tests for serum ferritin seem to indicate the presence of such a cytokine storm.

As yet, there is no Covid-19 vaccine

In many countries, official policy now tries to prevent a peak in the disease of such a magnitude that hospitals are overburdened. Hence measures like cancelling major events and the closure of cafes and restaurants. In due course, officials hope, there will be enough people with antibodies in the blood in order to stop the outbreak. Temporise the condition, is the motto. People can also show responsibility – it’s not just their own health that is at stake but also that of the fellow citizens. As one observer put it: you should live your life as if you are infected already, but don’t want to spread the virus any further. For the time being, there is no proper vaccine yet. There is a number of candidate vaccines, but these need to be tested on activity and safety first. Such tests are absolutely required. First on animals and then on human beings. Therefore, we need to wait another twelve to eighteen months before a vaccine is available. And then it may not be generally available, but used primarily for safeguarding doctors, nurses and vulnerable people. Today, the German government decided to block the acquisition of a company that develops such a vaccine by the American government – it needs to be available for everyone.

Covid-19 is surrounded with many uncertainties. Governments are being accused of taking the problem too lightly – or to act in panic. They have to steer in uncertain conditions. What is certain however: they cannot carry the entire responsibility. Responsible government leaders therefore have good advice for their people: take care of each other.

P.S. (March 18, 2020) Ensia today wrote that the disruption of natural habitats around the world may favour the spread of pandemics. Humans and wildlife get into more intense contact as natural areas are being developed for human activity; like when rainforest is logged for wood. Pathogens will look for new hosts and may find them in humans. This mechanism more or less resembles the rise of Lyme disease in temperate climates. A growing number of scientists fears that pandemics like that of Covid-19 could happen more often.

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