An Indonesian government-commissioned survey states that more than 85 percent of Indonesia’s population has antibodies against Covid-19. Epidemiologists warned it was not clear whether this immunity could help contain a fresh wave of coronavirus infections.

The survey was conducted between October and December by researchers at the University of Indonesia. They found Indonesians had developed antibodies from a combination of Covid-19 infections and vaccinations.

Indonesia’s second wave of infections — driven by the Delta variant — peaked in July and August, with infections plummeting from more than 50,000 a day to just a few hundred a day in recent months.

The antibodies may provide some protection against new variants, including the highly contagious Omicron.

Omicron has infected more than 250 people in Indonesia, but most cases have been imported and a handful of local cases have not so far brought the type of surge recorded in many countries.