BCG%20complications

1
BCG complications
2
BCG complications

• Local ulcers and regional lymphadenitis in normal
  hosts 4 to 30 per 1000 vaccinated infants
• Osteomyelitis (0.1 to 30 per 100,000 doses)
• Disseminated BCG infection (0.1 per 100,000 doses
• Death 0.02 per million

3
BCG revaccination in school childrenJ Pediatr
(Rio J) 2002 78 (4) 289

• Induration was present in 99.1 and erythema in
  91.6 of 438 children evaluated within 48h
• Pustules were observed in the first week in 26.1
  of 479 children. The first ulcers were seen
  during the second week
• By the tenth week, 69.8 of 463 children showed
  crusts but only 29.2 completed the healing
  process

4
Norma Oficial Mexicana-2000

• Will be applied to every newborn and to children
  up to 14 years of age
• 0.1 mL IM in deltoid region
• Asymptomatic newborn children with a positive HIV
  test must be immunized

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Norma Oficial Mexicana-2000

• Contraindications
• Low-weight newborns (lt2 kg)
• Immunosuppressed children, except asymptomatic
  HIV children
• Dermatitis in the deltoid region

6

• It is recommended that where the risk of
  childhood TB is high, BCG should be given to
  infants as early as possible, even if mothers are
  known to have HIV infection
• A recent review has concluded the benefits of
  immunization outweigh the risk of complications.

Pediatrics 1995 95414
7

• A consensus view currently exists, however, that
  BCG should not be given to infants with active
  HIV disease and that the vaccine is
  contraindicated in older asymptomatic children
  who are found to be HIV positive.

8
Immunization of children at risk of infection
with HIV

• The available data is not adequate to permit
  definitive conclusions about the effectiveness of
  BCG vaccine to protect HIV-infected children or
  adults against tuberculosis.

Bull World Health Org 20038161
9
Adverse events associated with BCG vaccination in
children infected with HIV
Dissemination 0-31
Lymphadenitis 0-24
Bull World Health Org 20038161
10
Adverse events associated with BCG vaccination in
children infected with HIV

• More than 28 cases of disseminated BCG infection
  have been reported in HIV-infected children and
  adults
• Progressive immune suppression can lead to the
  reactivation of latent BCG organisms, causing
  regional or disseminated disease

Bull World Health Org 20038161
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TB vaccines the future
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Current Tuberculosis Vaccine Development

• Advances in mycobacterial molecular genetics and
  the establishment of the genome sequence of
  Mycobacterium tuberculosis, make it possible to
  generate a vast new repertoire of potential
  TB vaccine candidates

13
Current Tuberculosis Vaccine Development

• An improved vaccine that would provide greater
  protection against M. tuberculosis, although
  technically feasible, is still far from being an
  achievable goal.

14
First US TB vaccine trial in 60 years begins

• A new vaccine, made with several proteins from
  MTB will enter the first phase of human safety
  testing
• This is the first recombinant TB vaccine to reach
  human trials in the US
• It combines two TB proteins known to stimulate
  strong immune responses in humans

NIH News Jan 2004
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Timing for BCG immunization
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Optimal time for giving BCG to infants

• There is some evidence to suggest that later
  immunization during infancy may confer a higher
  degree of immunity.
• BCG immunization at 3 months of age was found in
  one study to provide a higher rate of tuberculin
  protein skin responses with fewer complications
  than when given during the first three days of
  life.

Arch Dis Child 1999 8080
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Timing of BCG vaccination in Canadian Cree infants

• Lymphocyte response to PPD were measured at birth
  and at intervals
• The stimulation index in infants who received
  vaccination at birth rose from 3.1 to 35.3
• The SI in infants who were immunized between 9
  months and 2 years rose from 2.2 to 52.9 (plt0.05)

Am Rev Respir Dis 1989 1401007
18
Impact of BCG vaccination on the TB epidemic
19

• The impact of past BCG vaccination programs is
  difficult to assess
• The introduction of BCG programs in many
  countries coincided with social, economic, and
  health changes that might themselves reduce the
  incidence of tuberculosis

20

• Many of the vaccines we use routinely in children
  induce herd immunitybreaking the transmission of
  infection from one individual to the next,
  protecting thereby the unimmunized as well as the
  immunized and resulting in dramatic reductions in
  incidence

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• We cannot expect this of BCG
• The vaccine, given to infants and children, may
  protect the immunized individuals (somewhat
  unreliably) but will do little else to check
  the spread of the disease and thus can do little
  ultimately to control TB

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• Children with TB pose a negligible infectious
  risk to others. They acquire TB not from each
  other but, for the most part, from adults with TB
  not preventable by BCG
• Vaccination at birth has no effect on
  transmission of TB in adults, who represent
  the bulk of highly infectious cases

23

• Vaccination at school-leaving age, practiced in
  Britain and in Norway, was developed to address
  this deficiency, but so far there has been no
  unequivocal demonstration of the effectiveness of
  this strategy in reducing transmission of M.
  tuberculosis.

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Conclusions
25

• The protective efficacy is uncertain and
  unpredictable (varied from 0 to 80)
• Protective effect against meningeal TB of 64 and
  against disseminated TB of 78
• Skin test reactivity resulting from vaccination
  does not correlate with protection against
  tuberculosis

26

1. BCG should not be given to infants with active
   HIV disease it is contraindicated in older
   asymptomatic children who are found to be HIV
   positive
2. It may protect the immunized individuals it will
   not affect the spread of the disease and thus can
   do little ultimately to control TB