Earlier this week, six aid workers and one doctor were gunned down in the north-western Swabi region, and last month, nine people were killed while delivering polio vaccinations across Pakistan.
The Pakistani Taliban is suspected to be behind the attacks - it claims vaccinations are a plot to sterilise Muslims.
Presenter:Michael Edwards, South Asia Correspondent
Speakers: unnamed husband of one of the women killed; Ali Dayan Hasan, head of Human Rights Watch in Pakistan
MICHAEL EDWARDS: The attack was swift, brutal and seemingly senseless. Six aid workers and a doctor were shot dead when gunmen opened fire on their van in the Swabi District, about 75 kilometres north-west of Pakistan's capital, Islamabad.
The husband of one of the women killed says his three-year-old son was taken out of van before the shooting started.
VICTIM'S HUSBAND (translated): I called her half an hour before she had finished work. I told her that I would come and get her. Then I went to put petrol in my car. While I was at the petrol station, I received a phone call saying there had been a shooting on the vehicle. I rushed there to find them dead inside the vehicle. My child had been taken out of the vehicle before they shot the women.
MICHAEL EDWARDS: The victims worked for the NGO 'Support with Working Solutions'. The organisation is involved with health education in underdeveloped parts of the country. It runs a school and helps with the vaccination of children against polio - a disease that can cripple or kill within hours of infection.
In December, nine people delivering polio vaccinations were killed in Pakistan. The Taliban is suspected to have carried out the killings.
Ali Dayan Hasan is the head of Human Rights Watch in Pakistan.
ALI DAYAN HASAN: These attacks are taking place essentially because the Taliban and their affiliates view NGO's as Western agents and seek to erode their influence and seek to prevent them from operating in areas which they perceive as their domain.
MICHAEL EDWARDS: Disease is a constant problem for developing countries such as Pakistan. It is one of just three countries where polio is still endemic.
The UN children's agency UNICEF and the World Health Organization have suspended their anti-polio programs in Pakistan.
Ali Dayan Hasan says the attacks have reversed many of the gains made in recent decades against polio.
ALI DAYAN HASAN: Absolutely, polio in fact had been eradicated in Pakistan and it has made a comeback because the TTP (Tehrik-i-Taliban Pakistan) i.e. the Pakistani Taliban insists that somehow polio vaccination is a Western conspiracy. They know perfectly well that it is nothing of the sort. It is just that health workers are easy targets.
MICHAEL EDWARDS: There has been particular opposition to vaccination campaigns after a fake CIA hepatitis vaccination drive helped to locate Osama Bin Laden in 2011.
Ali Dayan Hasan says the Pakistani Taliban is responsible for war crimes against the public.
ALI DAYAN HASAN: This includes the large scale targeting of civilians going about their business, attacks on market places where you will find a hundred or more people have been killed in repeated attacks, attacks on health workers. It includes attacks on educational personnel.
MICHAEL EDWARDS: The World Health Organization fears polio could spread beyond Pakistan and into other parts of South Asia and the Middle East.