The COVID-19 vaccines authorised in Switzerland were developed to work against the original virus (including the Alpha variant). It is clear that while the vaccines currently available provide less protection against the Omicron variant, the efficacy of the booster is good.
According to the latest data, in the first few weeks after full vaccination (initial immunisation) you’re well protected from infection, mild illness and severe illness requiring admission to hospital. Protection against infection and mild illnessdiminishes rapidly and substantially for everyone. Protection against severe illness likewise diminishes over time, but this happens less quickly, over several months, and the extent of the decline depends of the age of the vaccinated person.
With the booster you can increase your protection again. The risk of a severe case of COVID-19 requiring hospitalisation can be substantially reduced. In addition to this, after the booster you are also well protected again for several weeks against infection and mild cases of the disease. A booster is therefore urgently recommended from four months after initial immunisation.
So far it has not been possible to gauge how long the protection provided by the vaccines against severe illness requiring hospitalisation caused by Omicron lasts. After 3-4 months this efficacy is still very high. It is likely to last significantly longer than protection against infection with mild illness. With earlier variants (e.g. Delta), the efficacy against severe disease involving hospitalisation was significantly higher and longer lasting than the efficacy against mild disease.
Some vaccine manufacturers are already working on modified vaccines against new variants. However, it is still unclear whether their use will be necessary in the future.
For more information on protection against the Omicron variant, see the question “How well am I still protected if I haven’t had a booster?”