Militants entered Matni Hospital in Peshawar, the capital of Khyber-Pakhtunkhwa province, and fired indiscriminately. Polio vaccinator Zahid Gul was killed instantly and two others sustained severe injuries.
No group claimed responsibility for the incident but the Taliban has been blamed for a spate of attacks on polio vaccination workers, accusing them of being Western spies and part of a plot to "sterilise" Muslims.
Taliban has been blamed for a spate of attacks on polio vaccination workers
Dozens have died in these attacks. In June last year, the Taliban imposed a ban on polio vaccinations in parts of the tribal belt and said the restriction would last till US drone attacks cease.
At least 260,000 children in North and South Waziristan have not been vaccinated since July 2012. On December 13, gunmen attacked two separate polio teams in northwestern Pakistan, killing one polio worker and two police guards.
On November 23, militants also kidnapped teachers for supporting an anti-polio drive but they were later released. Pakistan is one of only three countries where polio is endemic.
The number of cases in the country reached 77 this year, up by nineteen from the whole of last year. The World Health Organisation (WHO) has described Peshawar as "the international reservoir of polio".
Cricketer-turned-politician Imran Khan's Pakistan Tehrik-e-Insaf and provincial health experts recently agreed to launch the "biggest ever vaccination campaign" in the region.
The initiative is being led by party general secretary Jehangir Tareen. One of the suggestions under consideration is to employ renowned health experts such as Mohammad al-Muhammadi, who played a vital role in combating polio in Sudan, Yemen and Somalia.