At the very beginning of the corona virus pandemic, people were always hoarding: warmth, sun and UV light are supposed to contain the virus. So everything will be better in the summer?
"We liked to know that, too," said susanne glasmacher, spokeswoman for the robert koch institute. There will be a "certain effect", but the lack of basic immunity of the population is such an advantage for the virus that it will continue to spread. Thomas schulz, head of virology at the hannover medical school, expects a "small effect" that is not significant. Clemens wendtner, head of the infectious diseases clinic at munich’s schwabing hospital, also expects a slight slowdown in the summer, but cautions: "we must not delude ourselves into thinking that higher temperatures will cause the virus to disappear."
According to melanie brinkmann, professor at the institute of genetics at the technical university of braunschweig, and virologist prof. Friedemann weber from gieben the virus can be destroyed by warmth on surfaces exposed to direct sunlight. The UV component of sunlight could damage its genetic material.
The problem: in principle, the effect of summer does exist, as shown by the usual course of influenza, said schulz. But the chance of the new coronavirus replicating in a population that is largely not immune is far better, he said. The dose of UV light that occurs in the air has little influence, he said. Brinkmann and weber, on the other hand, explained that the human coronaviruses, which are related to sars-cov-2, are most active in winter: "we therefore hope that this also applies to sars-cov-2."
Due to the largely missing immunity against the new coronavirus, all disadvantages of the summer for the virus were not sufficient to push it back, also RKI spokeswoman glasmacher said. She referred to the H1N1 swine flu virus, which broke out in april 2009 and continued to set off many flu traps throughout the summer and well into the following year.
Schulz can imagine that warmth and sunlight can print the virus’s so-called reproduction number – "but only slightly". This indicates how many people on average are infected by an infected person. "To anyone who says it’s not all that bad, that all the cold viruses went back in the summer, all i can say is: dream on!", emphasized schulz.
The berlin virologist christian drosten had said in the NDR podcast that a pandemic virus is not stopped very much by social distancing, UV light and warmth, for example, "but definitely a bit". According to treasures, "half a unit" of the reproduction number could be subtracted in summer.
Whether there will be another surge next winter depends, according to brinkmann, on the number of infected people in late summer and fall, but also on testing and treatment options, the interruption of infection chains and – "all of us behaving".
As long as there is no vaccination, we have to expect a flare-up of infections around october, wendtner said. It is possible that there will no longer be hotspots, as is currently the case, but that the virus will spread to cover the whole area. "We will carry covid-19 further into 2021"."Whether all the events that were canceled this year or postponed until next year, from the olympic games to oktoberfest, will be able to take place is an open question. In any case, schulz demanded: "distance, distance, distance."