Two polio vaccinators — a mother-daughter team — were shot dead in Pakistan on Thursday, the first time in two years that the polio eradication drive had been shaken by assassinations.

While tragic, the killings in Baluchistan Province will not seriously disrupt Pakistan’s eradication drive, said one of its leaders.

“We are very close to winning the battle,” said Aziz Memon, a textile executive who heads Rotary International’s local polio vaccination efforts.

Last year, Pakistan had only eight confirmed cases of polio paralysis; four years ago, the nation had 306.