Tuberculosis was declared a global emergency by the World Health Organization (WHO) in 1993, and Mycobacterium tuberculosis is now considered responsible for more adult deaths than any other germs. Bacille Calmette-Guérin (BCG) vaccination provides protection against tuberculosis, especially in childhood. It is a live attenuated vaccine; meaning, it contains a strain of tuberculosis bacteria in an inactive form just enough to produce protective antibodies inside the body against the deadly disease without causing overt disease manifestations.
BCG vaccination provides protection against serious forms of tuberculosis in children, like the acute miliary tuberculosis and tuberculous meningitis which affects the outer covering of the brain. Whether BCG protects adults against tuberculosis is still a controversial issue. BCG is also used as an adjunctive immunotherapeutic agent in the treatment of superficial cancer of the urinary bladder.
In a few countries like the United States, Netherlands and Sweden, BCG is not recommended as a routine vaccination. Only high risk groups (children of immigrants and healthcare professionals)are advised immunization with BCG in these countries. Rest of the world follow the WHO guidelines and immunize newborns immediately after birth. In UK, only the children of the immigrants are immunized at birth. Other children are vaccinated at the age of 12–13 years. In some countries like Switzerland and Portugal, booster doses are given twice, both at school entry and exit. In Russia and Hungary, up to 5 booster doses are given before 30 years of age.
Complications of BCG Vaccination
The WHO estimates that approximately 100 million children receive the BCG shot every year. Given the huge number of vaccinations, complications reported from BCG vaccine is comparatively negligible.
The BCG vaccination complications may be localized or generalized and due to infectious or non-infectious causes. Infections may either be due to activation of the TB bacilli in individuals with lowered immunity or due to superadded infection at the injection site.
Local Complications of BCG Vaccination: Prevention and Management
Local complications of BCG vaccinations are usually mild and self limiting. Only a few require active therapeutic intervention. Adhering to proper injection techniques and choosing the correct injection site is important in preventing these local complications.
- BCG granuloma. Normally, a raised bump appears at the site of the injection approximately two weeks after the vaccination. This slowly enlarges to a size of 10 mm in 6–12 weeks’ time. The centre may break down with a minimal oozing of pus material. The ulcer slowly heals over a few weeks’ time, leaving behind a flat or raised scar. Usually no treatment except application of an antiseptic cream or solution is required in such cases.
- Local hypersensitivity reaction. This is common in those who are already sensitized with clinical or sub-clinical (asymptomatic) infection with tuberculosis. Also known as the Koch phenomenon or tuberculin reaction, the injected area becomes red, raised and indurated. This reaction is self limiting and requires no treatment. In severe reactions, topical steroids may be prescribed.
- Abscess formation and ulceration at the injection site. If the injection site becomes red, tender and swollen with pus, drainage and needle aspiration may be required. A short course of isoniazid or erythromycin will speed up healing of the abscess.
- Keloid scarring. Keloid scarring is the commonest non-infectious complication of BCG vaccination, where the scar overlying the injection site continues to thicken over the years. This is common among those with a tendency for keloid formation elsewhere in the body. Various studies have shown that the scarring and the resultant keloid formation can be minimized if the injection is given in the skin overlying the insertion of the deltoid muscle (the triangular lower end of the shoulder muscle). It will be beneficial if you remind the health worker about this while getting your child vaccinated.
Other rare local complications of BCG include the following:
- Lupus vulgaris, a type of skin tuberculosis, may appear at or near the site of injection after an interval of months to years.
- Scrofuloderma, a cold abscess caused by subcutaneous tuberculosis, can cause discharging ulcers for periods ranging from 6 to 12 months after the vaccination.
Both of these complications require treatment with medications against tuberculosis. Luckily, these are very rare.
Systemic or Generalized Complications of BCG Vaccination
Activation of the attenuated bacilli in BCG and systemic spread of the germ may occur in individuals with lowered immunity due to diseases (HIV, for example) or those on immune lowering medications like the biologicals or corticosteroids. Following are the important systemic or generalized complications of BCG vaccination.
- Regional lymphadenitis. Enlargement of regional lymph nodes may occur in some infants and children after BCG vaccination. Persistent and discharging lymph nodes are surgically removed. For mild enlargement, no treatment is necessary.
- Infection in a distant organ, like bones or joints. A rare complication, this occurs due to activation of the BCG bacilli in children with a lowered immune status. Anti-tuberculosis medications are given to clear up the infection.
- Disseminated infection with BCG bovine tuberculosis in the immune compromised. Though uncommon, dissemination of the bacilli could occur in those with lowered immunity, like the HIV positive individuals. Because of this, infants born to HIV positive mothers are not vaccinated unless they are proven to be HIV negative later on. This complication is extremely rare among the general population and occurs in 1–2 per million vaccinations only. Fatal dissemination is still rare, with an incidence of 1 in 10 million immunizations.
Most of the local complications of BCG vaccination can be avoided with appropriate injection techniques and correct choice of injection site. Generalized complications of BCG vaccinations are preventable by strict adherence to the selection criteria and by avoiding the vaccination in conditions of lowered body immunity. Children above 3 months of age and adults should be vaccinated only if they are tuberculin (Mantoux) test negative.
The majority of the rare complications arising from BCG vaccination are self limiting or respond to simple therapeutic measures. Despite these complications, BCG remains one of the safest vaccines in use and its benefits in prevention of serious forms of tuberculosis far outweigh the disadvantages and complications that may arise after the vaccination.
References
- CDC Fact Sheets: Tuberculosis: BCG Vaccine, Accessed 20th Oct, 2011.
- Paul EM Fine et al. Issues relating to the use of BCG in immunization programmes. WHO Publication. Nov, 1999.
- Grange JM. Complications of BCG vaccination and immunotherapy and their management. Communicable Disease and Public Health 1998; 1:84-8
Disclaimer
The information given in this article is for educational purpose only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.
Hanish Babu - Dr.Hanish Babu, MD is a dermatologist and a feature writer on Suite101.com with more than 200 articles related to skin diseases on the ...
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