What is the cause of suppuration after BCG vaccination in infants?

In order to prevent tuberculosis, newborn babies are required to receive the BCG vaccine. The BCG vaccination is very beneficial to the healthy growth of children, especially the severe types of tuberculosis that may endanger the lives of children. However, some babies develop suppuration after receiving the BCG vaccine, and the new mothers will blame themselves for their poor care. In fact, it is not the case. So why do babies develop suppuration after receiving the BCG vaccine? Let's take a look below.

Research by the World Health Organization (WHO) has confirmed that the average effectiveness of BCG vaccination in preventing tuberculous meningitis and disseminated tuberculosis is 86%; the effectiveness in preventing tuberculosis-related deaths is 65%, the effectiveness in preventing deaths from tuberculous meningitis is 64%, and the effectiveness in preventing deaths from disseminated tuberculosis is 78%. Over the years, thousands of lives have been saved through BCG vaccination.

There are generally no systemic reactions after BCG vaccination. The following local reactions are common:

Local reaction: After intradermal injection or skin scarification of BCG, redness, swelling and nodules will appear at the vaccination site in about 3 weeks, which will gradually soften in the middle to form small white pus scars. The pustules will break through and form scabs on their own, leaving a small scar after the scab falls off. Local reactions generally last about 2 months.

Lymph node reaction: After BCG vaccination, the vaccine reaches the whole body through the lymphatic system. Therefore, it is normal for the lymph nodes near the vaccination site to have a certain degree of tissue reaction. However, in a very small number of cases, especially infants under 1 year old, strong reactions may occur in the lymph nodes in the neck, armpits, and subclavian areas about 1 to 2 months after BCG vaccination. These may manifest as swollen lymph nodes, abscesses, and ulcers. The solution is as follows:

1. Swollen lymph nodes: You can use hot compress, 3 to 4 times a day, each time for 15 to 20 minutes. Early hot compress can often make the swollen lymph nodes dissipate on their own, or you can use sand plaster.

2. Abscess: Use a sterilized syringe to draw out the pus. It usually heals after 2 to 3 draws. This is a cold abscess, which is difficult to seal after surgical incision, so surgical incision is generally not performed.

3. Abscess rupture: Use 20% sodium para-aminosalicylate ointment, streptomycin powder or isoniazid, rifampicin powder

About one to two weeks after the baby is vaccinated with BCG, small red nodules will appear locally, which will gradually grow larger and cause slight pain and itching, but no fever. Pustules or ulcers will form in six to eight weeks. Scabs will begin to form in ten to twelve weeks, leaving a small reddish scar after the scab falls off, and the red color will gradually turn into skin color. If there are local pustules or ulcers after BCG vaccination, there is no need to apply medicine or bandage. But the area should be kept clean and clothes should not be worn too tightly. If pus flows out, wipe it with sterile gauze or cotton. Do not squeeze it and do not pick it out prematurely.

Why do babies develop suppuration after receiving BCG vaccination? Through the introduction above, I believe you also know that this is actually a natural phenomenon. New mothers don’t need to worry. This is not caused by inadequate care. Parents don’t need to blame themselves. Keep the area clean. It will heal and form a scab naturally in an average of about two to three months, and the scab will fall off naturally.