Question
The baby was hospitalized for convulsions at the age of one month and missed the BCG vaccination. Now three months old, the family is asking if the BCG vaccine can still be administered. Past treatment and outcomes: After treatment, the baby no longer has convulsions. The family hopes to receive advice.
Answer
The BCG vaccine is used to prevent tuberculosis. Since some diseases confer immunity from birth, the baby still needs to acquire this immunity. Parents can take the baby to a hospital for a PPD test to check if the baby already has antibodies. Typically, a nodule formed by PPD is less than 5 millimeters in diameter, indicating a negative reaction; a nodule between 5 and 9 millimeters indicates a weak positive reaction, and larger nodules indicate a stronger positive reaction. If the baby tests positive, there is no need for further vaccination because it indicates the baby may have been infected with Mycobacterium tuberculosis and has developed antibodies. Therefore, it is recommended that parents take the baby for a PPD test first.