The drive, which began earlier this month, is for protecting children from the two major childhood diseases.
State health services director Saritha R L said the health department has set a target to vaccinate 75 lakh children, belonging to the age group of nine months to 15 years under the initiative.
"The core objective of the drive is to prevent both the diseases-measles and rubella-through the single vaccine. The campaign is immensely successful in Kerala," she said here.
The first phase of the drive, held via government and private schools in the state, had achieved 46 per cent success, the official said in a statement.
Besides schools and hospitals, various other agencies including Indian Medical Association, on were also cooperating with the drive.
A high level meeting of health department officials also decided to carry out intensive campaign in those districts where the vaccination drive did not achieve expected results, the Health Director added.