The police said the attackers, armed with knives, had struck as the vaccination drive against measles and rubella was being conducted at a school in Edavoor on Thursday. They attacked the health workers and smashed Ms Shyamala's cellphone. The nurse has been admitted at a hospital in nearby Kuttipuram.
The police the attackers included people whose relatives had come for vaccination. "They entered the school and as the discussion with the doctors and nurses got heated, they began attacking the health officials," said Prateesh Kumar, a senior police officer.
Activists say the anti-vaccination groups spread messages on WhatsaApp, claiming vaccines lower life expectancy. But medical officers say the resistance has gone down over the last few years, with schools and institutions voluntarily opening their doors to vaccination drives.
Health Minister KK Shailaja has condemned the incident, saying, "Strict action will be taken in such cases. But these should be seen in isolation with no support from the public at large."