How long does the protection of the vector vaccines last?

This is being investigated continuously and can therefore not yet be answered conclusively. However, it is clear that the vector vaccine from Johnson & Johnson (Ad26.COV2-S, COVID-19 Vaccine Janssen) protects against a severe Covid-19 disease after several months with an effectiveness of only just around 70 percent. These observations refer to infections with delta variants. Initial studies show similar results for infections with the omicron variant.