Many people see the easing as an end to the pandemic – but that will be a long time coming, US researchers predict. You have developed several visions for the further course of the corona crisis.
Countries like Brazil and the USA currently report rapidly increasing numbers of corona infections. In other areas of the world, however, the number of cases is falling significantly – and people are breathing again.
Researchers around the world are studying the dynamics of corona spreading to put an end to the pandemic to be able to predict. One thing is certain: It remains unclear how the corona situation will develop.
“There is no crystal ball that tells us what the future holds,” says a publication by the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota. Nevertheless, US scientists have already created different scenarios for the duration of the corona pandemic in April. The “Deutsche Apothekerzeitung” previously reported on this.
Learn from previous pandemics
The team around the epidemiologist and CIDRAP leader Michael T. Osterholm has oriented itself to past pandemics. According to the researchers, these experiences could help to draw conclusions about the current situation.
Former InfluenzaAccording to the experts, pandemics are best suited for this – although corona and influenza viruses differ greatly. But the pandemics would have some things in common. The researchers refer to eight global flu pandemics, four of which have occurred since 1900: 1918 to 1919, 1957, 1968 and 2009 to 2010.
- Accordingly, both are the corona virus SARS-CoV-2 as well as the pandemic influenza virus, a novel pathogen against which the world population has little or no immunity.
- Both viruses are mainly spread by droplet infection via the respiratory tract, but also via aerosols.
- Asymptomatic transmission can occur with both viruses.
- The incubation period for influenza viruses is one to four days, that for Covid-19 two to 14 days. The longer incubation period with Corona allows the virus to spread unnoticed within the population.
- The proportion of asymptomatic cases is at Covid-19 with an estimated 25 percent, probably higher than with influenza with an estimated 16 percent.
- The R0 value (basic reproduction number) for Covid-19 is estimated at 2.0 to 3.0, but could also be higher. The R0 for the flu varied depending on the pandemic, but is estimated to be consistently around or below 2. This suggests that even severe pandemics with flu viruses were less communicable in the past than SARS-CoV-2.
The researchers concluded that this was Coronavirus spreads faster and often undetected to the world than the conventional flu. “A higher number of reproductions means that more people need to be infected and immune before the pandemic ends,” says her research report, “Covid-19: The CIDRAP Viewpoint.”
Travelers: According to some experts, the vacation season in the summer could cause the infection numbers to rise again in the autumn. (Source: Ralph Peters / imago images)
Even though there are usually no clear patterns, US researchers found that seven of the eight major flu pandemics had an early climax that disappeared over the course of a few months. A second high was then reached about six months after the first high. Besides, some would have Influenza– Pandemics showed further, smaller waves over the course of two years after the first wave, the scientists said.
Based on these findings, the scientists developed for the further course of the coronapandemic three possible scenarios. These relate primarily to the northern hemisphere. All follow the wave of spring 2020.
Scenario 1: smaller waves over a longer period
In the first scenario, the first Corona eruption this spring will be followed by further small waves in summer and in the years to come. However, these waves of disease will lose their intensity as early as 2021.
The extent can vary geographically, depending on what restrictions apply and how they are relaxed. In this scenario, the pandemic flattens out overall – but it also lasts for a long time.
Scenario 2: peak in autumn 2020 with subsequent waves
The second scenario of the US researchers paints a bleak picture. A new outbreak of corona occurs in autumn, which is larger than the first wave of infections.
This would require renewed restrictions to prevent the spread of infections and health system overload. This is followed by one or more smaller waves in 2021 until the curve flattens out significantly. This pattern is based on that of the Spanish flu in 1918 and 1919.
Scenario 3: slow decay of the virus without a new climax
After the peak in spring, the third scenario anticipates continuously occurring cases without a clear pattern. A new high is no longer expected. Even so, the pandemic will probably continue to go away until 2022, and the virus would continue to lead to illnesses and deaths.
While this pattern was not seen in previous flu pandemics, researchers are considering it for Covid-19.
Conclusion of the researchers: Corona for up to two years
“Regardless of which scenario the pandemic follows, we have to reckon with the fact that we still have to live with the corona virus for 18 to 24 months and that hot spots will continue to develop in different regions of the world,” the researchers conclude in their report.
Only in 2022 could immunity be achieved in two-thirds of the world‘s population – and thus global herd immunity to the coronavirus. It remains to be seen how infection numbers will develop in the individual countries.
Of course, developing a vaccine against could also SARS-CoV-2 play a crucial role and influence the course of the pandemic. Read more about the current status of worldwide vaccine projects here.