What happens after a newborn baby gets BCG?

The main purpose of giving BCG vaccination to newborns is to prevent tuberculosis, which is very harmful and there is currently no effective cure. Therefore, it can only be prevented through vaccination. Newborns will have some physical reactions after receiving BCG vaccination. These are normal phenomena and parents should understand them so that they will not worry when they occur. So, what will be the reaction of newborns after receiving BCG vaccination? Let’s take a look below.

1. Within 2-3 days after intradermal vaccination of BCG, there will be slight redness and swelling on the skin at the injection site. This is a non-specific reaction and will disappear quickly. About 2 weeks later, red and swollen papule-like lumps appear locally, which sometimes soften into small white pustules and later burst on their own to form superficial ulcers, usually no larger than 0.5 cm, with a small amount of pus, and then gradually form scabs, leaving slight scars after the scabs fall off. It lasts for 2-3 months and is a normal reaction to BCG.

2. After vaccination with BCG, a very small number of people will experience severe rash, purpura, shock and other abnormal reactions. At this time, timely diagnosis and treatment are required.

In addition, the following reactions may occasionally occur during vaccination:

(1) Lymph node inflammation: About 1-2 months after vaccination, lymph nodes in the neck, armpits, and above and below the clavicle become enlarged (greater than 1.0 cm). In cases where the reaction is too strong, the lymph nodes will be obviously swollen, and abscesses or ulcers may form, or there may be small pus scars at the vaccination site. The reaction to intradermal injection is often stronger than that to the scratch method. In addition, those who have a positive old tuberculin (OT) test may also have a stronger reaction after vaccination.

(2) Lupus-like reaction: related to the residual virulence of the tuberculosis strain.

(3) Scars: Scars are formed due to abundant granulation tissue and sometimes appear as keloids. They are more common in those who receive direct skin scratch vaccination without undergoing OT testing.

The above process generally lasts about 2 months. After vaccination with BCG, the lymph nodes near the vaccination site (mostly the axillary lymph nodes) will often swell. This is a normal reaction. As the vaccination site heals, the swollen lymph nodes will disappear on their own. Hot compresses can be used to promote its disappearance. If an abscess is formed, you can ask the doctor to use a syringe to extract the pus to promote healing. It generally does not affect the child's health.

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