[Medical Q&A] How do I know whether my child’s vaccination was successful?

Planner: Chinese Medical Association

Reviewer: Huang Lei, deputy chief physician, Fifth Medical Center, PLA General Hospital

Generally, there is no need to test after vaccination, because commercially available vaccines must undergo sufficient vaccination success rate research and meet industry-recognized standards before they can be marketed. Parents do not need to take their children for antibody testing just because of these rare cases of possible failure, which would increase unnecessary tension. However, if parents are really worried, they can take the following measures.

1. Go to the hospital to test for antibodies

Some antibodies can be tested in the hospital, such as hepatitis B antibody and rubella antibody, but the hospital cannot test whether antibodies are produced after other vaccines.

2. Participate in the Centers for Disease Control and Prevention’s vaccine antibody surveillance survey

The Center for Disease Control and Prevention regularly conducts projects such as immunization success rate monitoring and population antibody monitoring, including measles, polio, rubella, chickenpox, epidemic encephalitis B, mumps, diphtheria, whooping cough, tetanus, etc. Parents can consult the local Center for Disease Control and Prevention and voluntarily bring their children to participate.

3. BCG: Observation of scars and skin tests (referred to as "skin tests")

There is also a special vaccine, BCG, which can usually be confirmed by a scar on the arm. However, in about 10% of children, the scar may not be found or is difficult to identify. If the child has no scar after BCG vaccination, and the parents are really worried, they can do a PPD skin test on the child.

PPD is a tuberculin protein derivative and a reagent that can detect whether BCG vaccination is successful. Generally, the PPD skin test is injected into the left forearm. 48 to 72 hours after the injection, the doctor measures the degree of skin test reaction and obtains the skin test result.

Children start to receive various vaccines from birth, especially in the 0-1 year old stage. There are more than ten types of vaccines that must be administered and recommended vaccines. Parents do not need to worry about whether the vaccines have failed or antibodies have not been produced. As parents, what you really need to do is: take your children to get vaccinated in time, do not postpone or miss vaccinations for some unnecessary reasons, and vaccinate in time and according to procedures to bring the greatest protection to your children!