Explainer: should we be worried about the Covid-19 comeback?

Since the summer, Covid-19 infections and hospitalisations have been on the rise in the US, Europe and Asia but they have remained below previous peaks. © Keystone / Gaetan Bally

Covid-19 is back in the news. This week Switzerland and the United States (US) issued Covid-19 vaccination recommendations for this winter. How are Switzerland and other countries handling the limited, but worrying, new rise in coronavirus cases?

Since the summer, Covid-19 infections and hospitalisations have been on the rise in the US, Europe and Asia and while they have remained below previous peaks, the World Health Organization (WHO) estimated on September 6 that hundreds of thousands of people globally were hospitalised due to the virus.

In just a month Switzerland is planning to start a Covid-19 vaccination campaign for vulnerable people with health risks. Experts say boosters are still the safest protection towards the numerous variants that have been circulating, especially in the past few months.  

What do we know about the new Covid-19 variants so far?

The ever-evolving coronavirus continues to generate new variants that pose a challenge for public health officials globally, with some variants more worrisome than others. The new variants that epidemiologists and media are keeping a close eye on are all the latest members of the Omicron family. BA.2.86 (Pirola), EG.5 (Eris) and FL.1.5.1 (Fornax) variants seem to be responsible for the recent rise in infection cases. However, it is BA.2.86 that has been generating concern lately.

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It was initially identified in Denmark and Israel, but it is uncertain where it first originated. According to some studies, BA.2.86 features more than 30 different spike mutations, compared to the dominant variant in 2023, called XBB.1.5. The spike proteins are a key element because they allow the virus to enter human cells.

Should we be worried about Covid-19 again?

The World Health Organization (WHO) has warned of “concerning” Covid-19 trends in advance of winter in the Northern Hemisphere, calling for increased vaccinations and surveillance. At the end of August, WHO included BA.2.86 among the variants to be monitored, mainly because of the rapid increase in the number of infected cases and mutations.

“We are worried because it descends from a line of Omicron (BA.2) that was thought to be extinct, and because it has more than thirty mutations at strategic sites”, explained Antoine Flahault, director of the Institute of Global Health at the University of Geneva, to Swiss newspaper 24heuresExternal link.

Nonetheless, he added that there are no “alarming signs of this variant at the moment”. The fact that this variant has been considered “of concern” means that it has been placed under surveillance and holds a certain potential to spread further. “That doesn’t mean that the general public should be concerned,” Rudolf Hauri, president of the Swiss cantonal health authorities, told Swiss tabloid BlickExternal link.

The Swiss Federal Office of Public Health (FOPH) has said that new variants currently in circulation present new mutations which allow them to partially escape the immunity acquired by the population. In addition, the protection afforded by vaccination (or previous infection) gradually diminishes over time. Due to these two factors, to which will be added increased contact in indoor spaces, the FOPH expects an increase in the number of infections this fall and winter.

But compared to the pandemic years 2020 and 2021, the situation has changed significantly, it says. “Among people under 65 who do not have risk factors, the probability of a serious form of Covid-19 is minimal,” saidExternal link FOPH on September 11.

What’s the situation in Switzerland and how may it evolve?

In late August the BA.2.86 variant was detected in Swiss wastewater for the first time, together with a handful of other countries. According to the FOPH, around 1,000 Covid cases were recordedExternal link in the country last week, which corresponds to an incidence rate of +32% in 14 days.

Although the number of cases is currently increasing, “the number of hospital admissions due to severe Covid is currently limited,” Christoph Berger, head of Switzerland’s Federal Vaccine Commission (FVC) told Swiss public television, SRFExternal link.

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One of the biggest issues during the Covid-19 pandemic was the pressure on the sanitary system and the lack of hospital beds. In this case, Hauri assures that there “will no longer be a state of emergency because of Covid. If there is a shortage of beds, it’s only because there aren’t enough care staff.”

How effective are vaccines to cope with new variants?

According to ReutersExternal link, Moderna and Pfizer said that their updated vaccines “generated strong responses in testing against the highly mutated BA.2.86 subvariant”. The updated Moderna, Pfizer and Novavax shots are expected to be available this month.  

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As far as Switzerland is concerned, the FVC and FOPH recommend vaccination with an mRNA or protein-based vaccine adapted to the XBB.1.5 variant. The approval procedure for these vaccines is currently in progress at the Swissmedic Institute for Therapeutic Products.

How are countries around the world handling the latest coronavirus developments?

Although it’s hard to compare the number of Covid-19 cases, infection rates and hospitalisations around the world, we have looked at some of the measures adopted to stop the spread of the new variants.

Both the US and the Alpine country have issued Covid-19 vaccination recommendations earlier this week. But while the FOPH and the FCV have recommended the vaccine to vulnerable people, including over-65s, over-16s with pre-existing conditions or Down Syndrome, and pregnant women with pre-existing illnesses, the US have taken a broader approach, recommending it to everyone aged over six months.  

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Israel was one of the first countries to record cases of BA. 2.86 and one of the first to put into place some preventative measures. On Tuesday, the health ministry advised people with compromised immune systems to wear masks indoors and hospitals will test all new patients.

Elsewhere in Europe, countries like the United Kingdom have already started their vaccination campaign, a few weeks earlier than expected, especially for care home residents. This is because England recorded 34 cases of BA.2.86, so far and 28 of those are located in a care home in NorfolkExternal link.