536

REVACCINATION IN ADULTS

SIR,-Dr. J. C. Broom’s paper (March 22) promptsus to report some observations made in the Middle Eastin 1945.

Lieut.-Colonel (now Professor) R. S. Illingworth hadpointed out to us that a typical " reaction of immunity "was evoked by a heat-killed vaccine. To verify his state-ment a series of 20 previously vaccinated patients wererevaccinated with both heated and unheated vaccine bya standardised technique with a single scratch 1 cm. inlength. The response to both heated and unheatedvaccines was similar in each case and had the character-istics of the " reaction of immunity." In a secondseries of 20 cases where the areas of erythema wereplotted no constant differences between reactions toheated and unheated vaccine could be demonstrated.The figure shows the findings in 5 representative cases.To prove that the virus had been killed, material

from the same batch of heated vaccine was used to vac-cinate 10 previously unvaccinated infants. In no casedid a reaction occur ; later these infants were successfully-

Areas of erythema after vaccination with unheated and heated vaccinelymph.

vaccinated with unheated vaccine. Intradermal tests onrabbits also showed that living virus was no longerpresent after heating.As calf-lymph vaccine had been employed in these

experiments the agents possibly responsible for thereactions were bovine protein, contaminant bacteria, thepreservative added to the vaccine, or the proteins of thevirus bodies themselves. A series of 10 previouslyvaccinated patients were accordingly revaccinated withheated vaccine, unheated vaccine, bovine serum, and thepreservative. Reactions were noted only with the first 2.Dr. Dennis, of the American University of Beirut, kindlysupplied us with vaccine prepared by culture on chick-embryo membrane, the bacterial content of which wasnegligible. In 10 previously vaccinated patients similarA reactions of immunity " were obtained to this vaccineboth when heated and unheated. From these observa-tions we concluded that the " reaction of immunity"was an allergic response to the proteins of the virus bodiesin an individual sensitised by previous vaccination.

Circumstances had prevented us from reading therelevant published work ; but at this stage we discoveredthat similar observations had been made in 1901 by vonPirquet, who had reached the same conclusion. Wetherefore pursued our somewhat naive investigationsno further, believing that we had been in ignorance offacts well known to better-qualified workers in thisfield.

If our conclusions were correct it followed that the" reaction of immunity " in fact only indicated that thepatient was immune to variola when the vaccine employedwas known to be potent and viable. This explained ourprevious experiences of seeing patients in whom we hadourselves noted a " reaction of immunity " develop fatalsmallpox within two months of vaccination.Dr. Broom is clearly aware of the problem, but he has

noted a considerable number of cases in which unheatedlymph gave a " reaction of immunity " while heatedlymph gave no reaction. Our experience was differentfrom this : in a few a "reaction of immunity" wasgiven by unheated, but not by heated, lymph; in aboutan equal number the reverse was noted. We attributed

these discrepancies to faults in our technique, and repeti-tion, by producing similar reactions with both heated andunheated lymph, confirmed our view. Dr. Broom admitsthat the reaction to heated lymph may " closly simulate "that to unheated ; we concluded that the two wereindistinguishable. We share his uneasiness about certi-fication ; on several occasions we have seen the senseof security engendered by a " reaction of immunity "

prove disastrously false. London, W.1.

Leeds.

RONALD BODLEY SCOTT

R. P. WARIN.

CHEST DISEASE IN RAND MINERS

SIR,-In their letter of Feb. 8 Dr. Frazer and Dr.Walker rightly say that we have a miniature radiographyplant at the Witwatersrand Native Labour AssociationHospital, which has now been. in operation for severalyears. (Like them, we consider that our miniatures areof a verv high standard, as also are the large X-ray filmstaken to check the abnormalities seen in the miniature ..radiographs.) They were wrongly informed, however,that native workers suffering from phthisis may continueto work if they choose to do so. No native mine labourerfound to be suffering from pulmonary tuberculosis and/orsilicosis is allowed to continue working at the mines ; heis compensated and repatriated at the expense of themines. The compensation paid is, for silicosis, a sumequal to 36 times the amount of his monthly earnings,or .S180, whichever of the two amounts is the greater.Similar compensation is paid for pulmonary tuberculosiswhere the labourer has been engaged in a dusty miningoccupation for 8 or more years. Where the labourer isfound to be suffering from, pulmonary tuberculosis afterhaving worked in a dusty occupation for 30 days orlonger, he is given an amount equal to 20 times thesum of his monthly earnings, or 2100, whichever of thetwo amounts is the greater.

Dr. Frazer and Dr. Walker add that " during a briefvisit to the W.N.L.A. Hospital, no case of chest diseasewas seen." This seems strange, as we detain a largenumber of patients in hospital for sputum tests and otherinvestigations. Apart from these, all patients on themines who are suspected to be suffering from pulmonarytuberculosis and/or silicosis, after X-ray, clinical, or

sputum investigation, or loss of weight, are sent to ourhospital and detained here for examination by themedical officers of the Silicosis Medical Bureau, with aview to possible compensation.

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Witwatersrand Native LabourAssociation, Ltd., Johannesburg.

FRANK RETIEFChief Medical Officer.

BETTER CARE FOR THE HOMELESS CHILD

SiR,—Your annotation of April 5 suggests that thereis fairly general agreement with the recommendations ofthe Curtis Committee. But it is in fact surprising thatmore written protests have not appeared from workers inpublic-health, medical, and educational circles consideringthe extent of the disagreement which exists. The largestsingle group of children mentioned in the report is thatin public-assistance institutions. It is remarked withsurprise that 60 % of these children are short-stayadmissions-e.g., children admitted because the motheris having a baby. To this extent the total figures areinflated, for this group can hardly be described as

" deprived children." The committee consider thatmore accommodation for these short-stay childrenis badly needed, although they remark that there wasample accommodation in children’s homes generallybefore the war. The overcrowding of the public-assistanceinstitutions, therefore, seems to have developed withthe war, when women were encouraged to send theirchildren (even those of 2 years) into institutions whilethey either went to work or had a baby, and there waslittle warning to the mother that it might have a badeffect on the child’s emotional development. The legacyof 5000 homeless evacuees tells its own tale. Somepropaganda in reverse to emphasise the importance ofkeeping the child in its own or a, relative’s home wherethis is at all possible might now be instituted, with aquotation from the Curtis report on " the extremeseriousness of taking a child away from even an indifferenthome." To a young child even two weeks is a long time.