After getting a vaccination at an urban primary health centre in Hyderabad, a baby died and 26 children were hospitalized, officials said.
The children were given the vaccination at PHC Hospital in Nampalli on Wednesday and soon after they developed health problems. One of them even fell unconscious.
The hospital has refused to give details of the vaccine or the age group of the children.
The families of other children who were given the vaccination were also asked to bring their kids for medical examination.
A senior medical official said the tablet given after administering vaccines could have caused complications. He also assured tough action would be taken against those responsible.