Who are the recipients of BCG vaccination?

BCG Vaccine: Overview and Administration

The Bacillus Calmette-Guérin (BCG) vaccine is a non-toxic, live attenuated vaccine derived from Mycobacterium bovis, used to prevent tuberculosis. By administering BCG, young children develop a unique resistance to tuberculosis, thereby reducing the incidence and severity of the disease, particularly severe forms such as tuberculous meningitis. Additionally, it decreases the likelihood of subsequent endogenous reactivation. Let's delve into who should receive the BCG vaccination.

In China, BCG vaccination is administered to newborns immediately after birth. The target population includes infants under 3 months of age or children with negative results on the 5IU PPD (Purified Protein Derivative) test. (A negative result is indicated by a localized induration of less than 5mm 48-72 hours after the PPD test.) If a newborn weighs less than 2500 grams, is premature, experiences severe asphyxia at birth, or has aspiration pneumonia, BCG vaccination should be delayed until the child's health improves and meets the vaccination requirements.

Immunization Procedure and Dosage

1. For a dose intended for 1.5 individuals, BCG vaccine is mixed with 0.5ml of the accompanying diluent. Allow it to stand for about 1 minute, shake gently until dissolved and well-mixed. The dissolved vaccine must be used within 30 minutes.

2. Using a sterilized 1ml blue-capped syringe (25-26 gauge needle), aspirate the mixed vaccine and administer 0.1ml intradermally into the lower outer aspect of the left deltoid muscle.

Side Effects

Common Side Effects:

1. Around 2 weeks post-vaccination, localized redness and swelling may appear, which may progress to suppuration and form a small ulcer, usually healing with a scar after 8-12 weeks. No special treatment is usually required, but maintain local cleanliness to prevent secondary infection.
2. Pus-filled lesions, superficial ulcers, or secondary infections require medical attention. Apply 1% methylene blue (gentian violet) to dry and scab over pus-filled lesions, and apply antiviral powder to wounds without self-drainage or picking at scabs.
3. Large abscesses and ulcers (diameter exceeding 12.5mm) or those that do not heal for an extended period (over 12 weeks) should be promptly treated.
4. Lymph node reaction: Mild swelling of the axillary lymph nodes on the vaccinated side (rarely on the neck or contralateral axilla) may occur, usually resolving within 1-2 months without exceeding 12.5mm in diameter. If lymphadenitis or abscess formation occurs, seek immediate medical attention.
5. Transient fever may occur post-vaccination. Most cases are mild, resolving spontaneously within 1-2 days. For moderate fever or fever lasting over 48 hours, symptomatic treatment may be administered.

Rare Side Effects:

1. Severe lymph node reactions, including cheesy, cystic, and sinus types, can occur around the vaccination site or in the axillae, neck, or cervical lymph nodes. Prompt medical attention is necessary for these reactions.
2. A few cases of keloid scars may occur upon revaccination.