Pakistan and neighboring Afghanistan simultaneously launched fresh vaccination campaigns against polio Monday amid a resurgence in cases in the only two countries globally where the virus continues to be endemic and paralyze children.

The World Health Organization reported 64 polio infections this year: 41 from Pakistan and 23 from Afghanistan, up from six each in both countries in 2023.

Pakistani officials said the weeklong house-to-house nationwide campaign that was rolled out Monday enlists 400,000 polio workers, who aim to vaccinate over 45 million children under five against the paralytic disease.

“This is Pakistan’s third nationwide campaign this year, launched in response to the alarming increase in polio cases across 71 districts,” said Ayesha Raza Farooq, the prime minister’s point-person for polio eradication.