New corona variants: we interview Prof. Dr. Milo Puhan

New corona variants: we interview Prof. Dr. Milo Puhan

Prof. Milo Puhan, physician and epidemiologist, answers our questions about new corona variants and how to adapt this fall.

What do we know about the current corona situation in Switzerland?

In Switzerland, there is no longer good monitoring of the infection rate, so it is difficult to get an overview. However, it is known that the new variants are derivatives of the Omicron variant, some of which are more prevalent than others.

The infection rate seems to fluctuate steadily, but there is no reason to believe that new variants will be more dangerous than previous ones. We observe hospitalizations mainly in patients with comorbidities and see hardly any cases in intensive care units or severe courses of acute infection.


What is known about the new variants and Long COVID?

At present, we can only really make statements about acute infections. The long-term impact of new variants can only be assessed after some time has passed. A precise assessment will therefore only be possible in a few months. Whether the new variants cause more or fewer cases of Long COVID cannot yet be assessed.

In early variants, the risk of developing Long COVID was reduced with vaccination.

During wild-type and earlier variants, individuals with vaccination were less likely to develop Long COVID after infection than individuals without vaccination. However, the evidence is less clear as to whether newer Omicron variants reduce the risk of Long COVID per se, or whether the less frequent occurrence of Long COVID today can also be attributed to vaccination.

The development of new variants may also have an impact on the symptomatology of Long COVID affected individuals. Because of more severe courses of acute infection with early variants, the lungs were often also affected after the acute stage. However, this is more likely to be damage that occurred during acute infection. Since acute infections with the newer variants tend to be less severe, we now mostly observe typical post-viral symptoms such as fatigue. Otherwise, the clinical presentation is quite constant.

Wearing masks is still one of the most effective measures - we explain why here.

What should vulnerable groups and their close contacts do?

In autumn and winter, particularly vulnerable groups can protect themselves by opting for masks in crowds again. The mask remains the best preventive measure against COVID-19 infections. Of course, people can also get tested to protect those around them. However, the cost of testing is no longer covered in Switzerland, and this is not expected to change in the coming months.

If their health permits, people who are already affected by Long COVID can also be vaccinated. However, whether vaccination is appropriate should be evaluated individually with a physician. To date, it is unclear whether or not re-infection will worsen the course of Long COVID. There is also no clear evidence yet about the effect of vaccination on the further course of symptoms in people affected by Long Covid. However, I think that if the state of health allows it, vaccination might offer more control.

For everybody, it is still important to follow recommendations of the Eidgenössische Komission für Impffragen (EKIF): it recommends revaccination against COVID-19 for vulnerable individuals, similar to the recommendations for influenza vaccination. However, recommendations for healthcare workers differ: while influenza vaccination is recommended for healthcare workers, no corresponding recommendation has been made for COVID-19 vaccination. Therefore, the suggestion to wear a mask in case of increased risk applies here as well.


We thank Professor Puhan for the interview.


Puhan Milo Zh

Prof. Dr. Milo Puhan, Institute for Epidemiology, Biostatistics and Prevention (EBPI), University of Zurich.

Prof. Milo Puhan is a physician and epidemiologist. He heads the EBPI, is co-founder of the Corona Immunitas Initiative and President of the Swiss School of Public Health (SSPH+).

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