BCG complications

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

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

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

Norma Oficial Mexicana-2000 Contraindications

o Low-weight newborns (<2 kg)

o Immunosuppressed children, except

asymptomatic HIV+ children

o Dermatitis in the deltoid region

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; 95:414

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.

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 2003;81:61

Adverse events associated with BCG vaccination in children

infected with HIV

Dissemination 0-31%

Lymphadenitis 0-24%

Bull World Health Org 2003;81:61

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 2003;81:61

Adverse events associated with BCG vaccination in children infected with HIV

TB vaccines: the future

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

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

Current Tuberculosis Vaccine Development

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

Timing for BCG immunization

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; 80:80

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 (p<0.05)

Am Rev Respir Dis 1989; 140:1007

Impact of BCG vaccination on the TB epidemic

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

Many of the vaccines we use routinely in

children induce herd immunity—breaking

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

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

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

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.

Conclusions

1. The protective efficacy is uncertain and

unpredictable (varied from 0 to 80%)

2. Protective effect against meningeal TB of

64% and against disseminated TB of 78%

3. Skin test reactivity resulting from

vaccination does not correlate with

protection against tuberculosis

4. 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

5. It may protect the immunized

individuals; it will not affect the spread

of the disease and thus can do little

ultimately to control TB