Chronicle: Even more flashes of light in the corona darkness

It is worth remembering that just four months ago, covid-19 was a completely unknown disease to the world. Since the first cases were reported at the turn of the year, the acquisition of knowledge has been going fast. Several promising vaccines against the disease have already begun to be tested on larger groups of people, which is a record. At the head are two Chinese companies, one of which is supported by the Chinese army. A British research group is also advancing rapidly. Earlier this spring, six macaques each received a dose of their vaccine and were then exposed to large amounts of the corona virus, without getting sick. 

Still, it is long before we know if any of these vaccines will provide adequate protection against covid-19 and do not cause serious side effects, but such a rapid development has never ever occurred.

This week, disturbing reports came from South Korea, where hundreds of people who were declared well from covid-19 were once again tested positive. However, according to Korean health authorities who have investigated the cases, this is not due to people getting sick again, but to the tests that have detected residues of the virus in the blood. 

"You can have residual virus particles in the airways and mucous membrane for a long time and that doesn't mean you have an active or new infection," says Petter Brodin, who is researching the human immune system at the Karolinska Institute. According to him, it is also likely that those who have had covid-19 also have at least some immunity to the disease.

- To succeed in curing oneself from the virus without developing immunity would be very strange. Most experts assume that you will receive some protection, but how long is uncertain at present.

SARS-CoV-2 seems relatively stable, and so far does not change in any worrying direction, says Piotr Kramarz, Deputy Head of Research at the European Infection Protection Institute ECDC. According to him, it is not unbelievable that the virus will eventually change into a milder variant.

The ECDC makes regular assessments of the spread of infection in Europe. Their latest report has a positive message. In two-thirds of the Member States, the number of new cases is steadily declining, and the spread of infection has decreased by 18 percent since April 8, which is considered to have been the peak. It remains to be seen whether this development will last.