BCG for TB(Tuberculosis)

Posted January 10th, 2017 by Duken

I had a BCG jab in November & the areas still red & itchy….. this aint right is it?

I think that’s right.

Bacillus Calmette-Guérin (or Bacille Calmette-Guérin, BCG) is a vaccine against tuberculosis that is prepared from a strain of the attenuated (weakened) live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans by being specially cultured in an artificial medium for years. The bacilli have retained enough strong antigenicity to become a somewhat effective vaccine for the prevention of human tuberculosis. At best, the BCG vaccine is 80% effective in preventing tuberculosis for a duration of 15 years, however, its protective effect appears to vary according to geography.

After the vaccination a small red spot usually develops within 2-6 weeks. After a few weeks the spot usually becomes scaly, crusting and with slight bruising. This will eventually heal to form a round flat scar. It is better if you leave the injection site uncovered as this will aid in the healing. In some cases a small shallow ulcer appears. In the rare situation that a reaction occurs medical advice should be sought from your doctor or practice nurse as soon as possible.

Mantoux test

The BCG vaccination should never be given to a person who has a “positive” tuberculin skin test. A “strong” positive test might indicate that you will need to visit a chest clinic for further assessment.

A Mantoux Test is done before having the BCG vaccination in all persons over the age of 6 years or earlier if the child has been “at risk” of TB. Routine vaccination is no longer carried out in schools – however, a new improved immunization programme targets those at greatest risk to the disease.

The Mantoux test is given “intradermally” into the lower left forearm. The tuberculin test is injected into the arm at skin level. After the injection some people experience mild itching or swelling but this usually goes within a week.

You will need to avoid itching the injection site, keeping it clean and dry – water won’t hurt it so you can bath or shower – but try not to scrub it! Don’t put a bandage on the site and don’t use any lotions or creams on the injection site.

When planning your vaccine schedule, the test can be given at the same as other “inactive” vaccines. If you need “live” vaccines you should have these four weeks before or after the test as they can “suppress” the result.

The results are read 48 to 78 hours later and you should ideally make this appointment when you make one for the Mantoux Test.


  • •Many thanks, I managed to miss out on the whole thing in school so it was all new to me. Pleased to say that the swelling has gone down & it’s no longer itchy. There’s still a small red spot but I guess it’ll turn into a scar in due course.
  • Yes….It is normal…..but this was months ago..stop whining….
  • a max of 4 weekz iz fine… aftr tht wud betr c the doc… jus kiddin… :P… he he… gues itz ok unles itz swelin n sored… peace!!!
  • Did you have the skin test before the vaccine? If you had a positive result to the skin test, you should not have been given the vaccine.

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