BCG immunisation of infants by percutaneous multiple puncture

Administration of the BCG vaccination using the multipuncture method in schoolchildren: a comparison with the intradermal method

BACKGROUND

BCG vaccination using the multipuncture device (the Heaf gun) is recommended in the UK for infants and very small children only. The aim of this study was to investigate the rate of conversion of the tuberculin test, the safety and acceptability of BCG vaccination using the multipuncture device and to compare it with the conventional intradermal method in schoolchildren.

METHODS

Schoolchildren attending schools in Tower Hamlets who were eligible for BCG vaccination were tuberculin tested using the Heaf gun. Those with grade 0-1 reaction were randomised to receive BCG vaccination using either the multipuncture or the intradermal method. The site of BCG vaccination was inspected after eight weeks for inflammatory changes and scarring. A questionnaire about pain and inflammation at the site of vaccination was completed. The Heaf test was repeated at eight weeks and its results were assessed by an examiner unaware of the results of the previous Heaf test and the method of BCG administration. The Heaf test conversion was deemed to have occurred if there was a change of at least one grade in the response.

RESULTS

One hundred and sixty nine children (83 girls) of mean age 11.8 years completed the study, of which 81 received BCG by the multipuncture method. The Heaf test did not convert in 22 of 81 (27. 2%) receiving BCG by the multipuncture device compared with six of 88 (6.8%) who received the vaccine by the intradermal method (odds ratio 0.2, 95% confidence interval 0.07 to 0.55). The BCG scar was visible in all children who had intradermal BCG compared with 67 of 81 (81.8%) of the multipuncture group. The multipuncture method was less painful and caused fewer inflammatory changes than the intradermal method.

CONCLUSIONS

In schoolchildren the multi-puncture device for administering BCG caused a lower rate of tuberculin conversion as measured by the Heaf test and less of an inflammatory response than the intradermal method. The method needs to be modified before it is applied on a wider scale to schoolchildren.

Tuberculin reactivity after neonatal percutaneous BCG immunisation

A total of 348 neonates of Asian ethnic origin were given percutaneous BCG vaccination using a multiple puncture head. Fifty five (15.8%) were tuberculin negative when tested 6-9 weeks after vaccination, a significantly higher proportion than after intradermal vaccination. The number of abscesses after vaccination was however significantly lower.

Heaf status 12 years after infant BCG immunization

Uncertainty exists over the long-term influence of Heaf status and immunity of infant BCG immunization. BCG is offered to all Leeds Asian infants with uptake estimated at 86%. We have examined the effect of this immunization policy on the Heaf status of all 12- to 13-year-old children tested in the city in 1988. 6363 children (431 Asians) were eligible for Heaf testing of whom 5379 (366 Asians) were tested. 90 (25%) Asians and 4596 (92%) non-Asians had a Heaf grade 0-1 with no definite previous BCG and were, using current UK Department of Health recommendations, eligible for BCG immunization. With an annual incidence of tuberculosis in Asian children in Leeds of only 6 per 100,000 it is probable that most of the 75% of Asian children who did not require immunization had persisting immunity from their infant BCG rather than as a result of primary infection. We conclude that infant BCG immunization is effective at providing appropriate immunity, avoiding repeat BCG, in most children at age 12 years.