"International health experts say the global campaign to eradicate polio has reached a critical stage, with Afghanistan, Pakistan and Nigeria the only countries where the crippling and potentially deadly virus is still prevalent," VOA News reports. "Health officials in Pakistan say they are redoubling efforts to vaccinate every child against polio after 198 new cases were reported in the country last year, the largest number anywhere in the world," the news service notes, and highlights several challenges to the efforts, including "an ongoing insurgency and the influx of millions of Pakistani and Afghan refugees" and public opposition to the vaccinations resulting from misperceptions and concerns about safety (Padden, 6/9).