abortion in 121 cases. Early in the series curetting wasalmost always performed, though later it was restricted tosituations in which abortion was still incomplete after24-48 hours or when there was bleeding. The length ofstay in hospital ranged from 3 to 16 days. Lachelin and

Burgess are so satisfied with this treatment that they havefelt no need to use hysterotomy in their unit.

MEASLES VACCINATION

THE preparation of satisfactory measles vaccines hasseemed a long business, particularly when the story wascompared with the more or less rapid development ofpoliovaccines. There were several reasons for this seemingdelay. Although measles can have its serious and evenfatal complications, it is, for the most part, a mild illness,so no great urgency arose for its eradication. A killedmeasles vaccine was not too hard to make; but, althoughfree from unpleasant side-effects, it had the potentialdanger of inducing only transient immunity. Measles

might thus be delayed until adult life, when it is a muchmore severe disease. Moreover, the efficacy of a killedvaccine (given alone, rather than as a prelude to an

attenuated vaccine) would depend on repeated boosterinoculations, which, experience suggests, would mean apoor acceptance-rate. These considerations prompted thesearch for live measles vaccines that could be given as aonce-and-for-all protection. Unfortunately, unlike polio-myelitis, measles has no really suitable animal-model

system by which to measure virulence of potential vaccinestrains; and all such assessments have had to be made inman. Perhaps because of this difficulty, relatively fewstrains of this virus have been examined and nearly all ofthem have been derived from the so-called Enders-Edmonston strain. The Schwarz strain is used in one ofthe British vaccines and the Beckenham strain in the other.None of the available vaccine strains can be regarded asideal, since they all produce some reaction-usually a mildfeverish illness and a rash. These reactions are generallyso mild that health authorities in this and in many othercountries have felt justified in recommending mass vac-cination.l This action has been particularly urged indeveloping countries-for reasons set out on p. 660 byDr. Gans in his account of events in Biafra.

Clearly, comparative trials of the available vaccinesmust continue; and another of this kind is described byDr. Jean-Joseph and his colleagues on p. 665. The trialwas conducted in Mali and two vaccines were used: oneincorporating the Schwarz strain and the other theEdmonston-B. Again, a Schwarz vaccine producedmilder reactions than one containing an Edmonston-derived virus. In the Mali trial, the Edmonston-B straininvoked a slightly higher antibody response, but the sero-conversion-rates of the two vaccines were similar. Thesefindings will encourage advocates of Schwarz vaccines,but they should not be judged as a comparison of the twoBritish vaccines, because the Edmonston-B strain isdifferent from the Beckenham strain. The results are,however, comparable to those recorded in a trial of thetwo British vaccines in Hong Kong.2 2

News came last week that a British measles vaccine

containing the Beckenham strain had been withdrawn.1. See Lancet, 1968, ii, 616.2. Hong Kong Measles Vaccine Committee. Bull. Wld Hlth Org. 1967,

36, 375.

The reason given was that its administration had beenassociated with three cases of encephalitis, one of whichwas fatal. Detailed comment must await further informa-tion. The capacity of the measles virus to attack thenervous system, immediately or after some hidden phase,3engenders caution. But the campaign for measles eradica-tion should continue. The Schwarz strain has not beenincriminated; and the hitherto blameless Beckenhamstrain may survive this setback. Inevitably, the use of livevaccines always entails some small risk, to be weighedagainst the dangers of allowing an infection to go un-checked. For measles, one estimate is that a typical epi-demic year in Britain will mean 35,000 patients withserious complications and some 600 of them will haveencephalitis.4

MIGRATION AND GENERAL PRACTICE

IN discussions on the extent to which the NationalHealth Service depends on staff trained outside Britain,most attention has been paid to junior doctors and nursesin the hospital service. General practice has receivedlittle mention, perhaps because, as Dr. Cargill shows onp. 669, there has until recently been nothing to discuss.Even now, of more than 23,000 family doctors in theN.H.S. only a small proportion qualified overseas, and ofthese only a fraction will have come from developingcountries. In Essex and Birmingham (the two areas whichCargill examined) the annual recruitment-rate of Asianand Middle East doctors entering general practice in themid-1960s was less than 1% of the total list, and so thetotal proportion cannot for some time approach the

40% commonly cited for junior hospital staff. Butthere are other signs that an immigration/emigrationbalance similar to that recognised in the hospital servicemay one day become a feature of general practice. Justas Cargill has found a significant inflow of overseas doctorsinto general practice, so Professor Whitfield (p. 667) notesthat 10% of Birmingham graduates of 1959-63 can fairlybe regarded as permanent emigrants, that half of these arein " general practice " overseas, and that dissatisfactionwith general practice under the N.H.S. was the mostcommon reason for emigrating.Each year over a thousand G.p.-principal posts fall

vacant. The average list size has been growing steadily,and in some parts of the country practices have had to bedispersed because of lack of suitable applicants; indeed,the situation may have to be made temporarily worse if itis to benefit in the long term from vocational training ofthe type envisaged in the Todd Report. If this demand is

going to be met increasingly by overseas doctors it wouldbe interesting to know how many recruits are coming intogeneral practice after a number of years in hospital workand how many have not previously held a post in theN.H.S. In either case the postgraduate training whichthese doctors are traditionally supposed to be seeking is,at present, even less accessible in general practice than itis in hospital, where, in theory at least, they can workunder supervision. An Indian doctor who leaves anN.H.S. hospital for general practice may be less likely toreturn to India; as with 300 or so British-trained doctorseach year his migration may become permanent.

3. See Lancet, March 22, 1969, p. 611.4. Miller, D. L. Br. med. J. 1964, ii, 75.

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