BCG Vaccine, Dr Yatin Bhole, Pediatrician, Pimpri Chinchwad

                                                                 BCG Vaccine

What is BCG vaccine?

  • BCG is bacillus calmette guerin.

  • It ia vaccine to prevent tuberculosis and sever tuberculosis. 

  • BCG vaccine is derived from the bovine tuberculosis strain.

  • It was first developed in 1921 by the French microbiologist, Albert Calmette, and the veterinary surgeon, Camille Guerin.

  • It continues to be the only effective vaccine against tuberculosis.

  • The two common strains in use are Copenhagen (Danish 1331) and Pasteur.

  • Copenhagen (Danish) was produced in India at the BCG Laboratories, Guindy, Tamil Nadu till recently.

  • ​The vaccine contains 0.1–0.4 million live viable bacilli per dose.

  • It is supplied as a lyophilized (freeze-dried) preparation in vacuum sealed, multi-dose, dark colored ampoules or 2 ml vials with normal saline as diluent. 

What type of vaccine is BCG?

  • BCG vaccine is a live vaccine.

  • They are live bacteria without capacity to cause disease.

  • After injecting it the recipient's immunity fights against it like it fights real infection.

  • Thus the recipient is prepared for actual real infection caused by disease causing bacteria by developing their immunity.

  • This is form of active immunity that is recipient generates immunity actively in itself.

Why is BCG vaccine necessary?

  • More than 1 million cases of pediatric tuberculosis occur every year.

  • The proportion of pediatric TB cases registered are increasing. 

  • Prevention of childhood tuberculosis is thus an important priority.

How it is stored?​

  • The vaccine is light sensitive and exposure to ultra violet rays. 

  • In lyophilized form, it can be stored at 2 to 8 degree C for up to 12 months without losing its potency. 

How is it administered?

  • Diluent is for reconstitution. 

  • Sterile normal saline can be used in place of diluent. 

  • BCG vaccine contains no preservative.

  • The reconstituted vaccine is stored at 2 to 8 C, protected from light and is discarded within 4–6 hours of reconstitution.

  • The recommended dose is 0.1 ml or 0.05 ml. 

  • Dosage does not depend on the age and weight of the baby. 

  • BCG injection is strictly intradermal, using a tuberculin syringe and a 26G / 27G needle.

  • Left shoulder at level of deltoid insertion is preferred for injection.

  • The selected site is swabbed clean using sterile saline and local antiseptics are avoided

What happens after BCG injection?​​​

  • ​A wheal of 5 mm at the injection site indicates successful intradermal administration of the vaccine. 

  • BCG adenitis is seem more commonly after subcutaneous administration.

  • Usually shows no visible change for several days.

  • Subsequently, a papule after 2–3 weeks. 

  • Which increases to a size of 4–8 mm at end of 5–6 weeks.

  • Papule heals with ulceration.

  • Scar after 6–12 weeks.

  • In some cases ulcer at injection site persists for weeks before scar appears.

  • No treatment is required for this condition.

  • Secondary infection at injection site may require antimicrobials.

  • Ipsilateral axillary/cervical lymphadenopathy can occur a few weeks/months after BCG injection.

  • Antitubercular therapy is of no benefit in such situations and should not be given.

  • The nodes regress spontaneously after a few months.

  • In some children, the nodes may even liquefy and result in an abscess.

  • Surgical removal of the nodes or repeated needle aspiration is the treatment of choice.

  • Antitubercular therapy is not recommended.

  • Disseminated BCG infection can occur but is extremely rare, may occur in babies with cellular immunodeficiency.

  • BCG should be avoided in the immunocompromised, especially those with cellular immunodeficiency.

When is BCG vaccine given?

  • At birth (for institutional deliveries) or at 6 weeks.

  • Catch up vaccination with BCG is recommended till the age of 5 years.

  • Routine tuberculin testing before catch up vaccination is not needed.

  • BCG is repeated once in children less than 5 years of age in the absence of a reaction/ scar.

How efficacious is BCG vaccine?

  • It decreases 75–86 % chances of getting miliary and meningeal form of the tuberculosis.

  • It decreases chances of getting  pulmonary tuberculosis by 50%.

Routine vaccination:
Should be given at birth or at first contact

Catch up vaccination:
May be given up to 5 years

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