Growing complacency about Covid-19 and politicisation of the pandemic response will cost lives as the world is hit by new waves of the virus in the coming months, Pfizer’s chief executive has warned.

Albert Bourla said people were growing “tired” of the measures introduced to slow the spread of the virus, while “politicians want to claim victory”.

Compliance with authorities’ requests for people to get booster shots would fall even among those who are already vaccinated, he predicted.

This, combined with waning immunity from previous infections and vaccinations, was likely to lead to “constant waves” of Covid variants and deaths, he said.

“I feel when I discuss [Covid] with my friends, people are ready to compromise and lower the bar: maybe we can accept a few more old people dying, [rather] than have to work with a mask,” Bourla said in an interview in Davos, Switzerland, where he noted that few attendees at the World economic forum’s annual meeting were masked.

“What worries me is the complacency,” he said, adding that the consequences could be seen in three to six months.

Global demand for Covid vaccines, such as the one that Pfizer developed with Germany’s BioNTech, has halved since the start of the year, according to Airfinity. The health data group said people in rich nations were reluctant to take repeated booster shots, while vaccine hesitancy remained common in poorer nations.

Pfizer on Wednesday unveiled an initiative to offer all of its patent-protected medicines and vaccines, including the Covid jab, to 45 lower-income nations on a not-for-profit basis.

Ghana, Malawi, Rwanda, Senegal and Uganda were the first countries to sign on to the “Accord for a Healthier World”. The countries would help identify and resolve hurdles beyond the supply of medicines, Bourla said, such as the need to improve diagnosis, education, infrastructure and storage.

Pfizer has invited other pharmaceutical companies to join the initiative, which is partly funded by the Bill & Melinda Gates Foundation, and asked governments, global health authorities and philanthropists to provide public