BCG VACCINATION

BCG VACCINATION

BCG (bacillus of Calmette* and Guerin*) vaccine is an attenuated live vaccine obtained from the bovine strain of tubercle bacilli. It produced controlled primary tuberculous infection. Thus, an immunity to tuberculosis without exposure to risks of natural infection is accomplished. There is some evidence that BCG also protects against leprosy and leukemia.

The current practice is to employ heat stable, freeze dried powder (to be reconstituted using normal saline) which should preferably be stored at 2 to 10 degree C. As recommended by the  WHO, it is the Danish 1331 strain of the bacilli, available in multidose vials. More recently, isonex-resistant BCG vaccine has also become available. Once the BCG vial is opened, it has got to be used within 4 hours. Leftover vaccine must be discarded.

Age to vaccinate

Direct primary vaccination against tuberculosis is recommended at birth or earliest contact after birth.

Site

 The standard site is the middle of deltoid(just above its insertion) over the left upper arm. When BCG and triple vaccination are being simultaneously given, it is advisable to choose different arms.

Method

 0.1  ml(0.05 ml neonates) of BCG is injected intradermally with a special tuberculin syringe. For mass immunization the jet injector is of distinct value.

Normal reactions following vaccination(Immunogenicity)

A papule appears in 2 to 3 weeks after vaccination. By about the fourth week, it grows in size 4-8 mm. Then it either subsides or sheds in to a shallow ulcer covered with a crust. This ulcer heals spontaneously in nearly 8 to 12 weeks time, leaving behind a tiny scar. After several years, this scar may fade and even entirely disappear.

These is, however, one noteworthy exception. If a tuberculin positive reactor is vaccinated, there is likely to be an accelerated response (Koch’s phenomenon) with a papule or red angry ulcer at the injection site after only 1 to 3 days and lasting about 3 weeks. This is almost harmless and does not disfavor the present practice of direct BCG without prior tuberculin (Mantoux) test.

It seems to be appropriate to do Mantoux test 2 to 3 months after BCG administration. In case it turns out to be negative, BCG  should be repeated.

Contraindication

1. Skin ailments like eczema and burns
2. Immunodeficiency (hypogammaglobinemia, symptomatic HIV, deficient cell-mediated immunity)
3. Immunosuppressant (e.g steroid) therapy
4. With in 4-6 weeks of immunosuppressive illness like measles
5. Pregnancy

Adverse reactions (Complications) and their Management

 These are uncommon and rather mild:

1. Accelerated reaction in tuberculous sensitive individuals.
2. Deep ulceration of the vaccination site together with superadded bacterial infection.
3. Simple Lymphadenitis involving axillary lymph gland (less than 1 cm in diameter) without any progression or signs of suppuration should be regarded as a normal, though somewhat exaggerated, response to BCG and a part of induced “primary complex”. It should be left as such.
4. Suppurative Lymphadentii. Axillary and /or cervical lymph glands may attain considerable size and, at times, develop suppuration and abscess formation. This is termed BCGosis or simply BCG adenitis. Pyogenic antibiotics may be given in such cases. Many surgeon, however, recommend excision of the glandular swelling. There is a good of consensus that every child with BCGosis should have at least X-ray of the chest. If it shows evidence of primary complex, a full antituberculous course is justified. If x-ray chest is clear , the child should receive only isonex, 5 to 10 mg/kg/day.
5. Keloid formation over the site of vaccination. Very rarely, Suppurative osteomyelitis and disseminated tuberculosis (in immunocompromised states may occur. Protective Efficacy BCG offers around 80% protection against serious form of tuberculosis (military and CNS tuberculosis), about 50% protection against pulmonary tuberculosis and no protection against simple tuberculous infection.