The addition of a parapertussis component to diphtheria–tetanus–pertussis vaccine reduces the agglutinogenic potency of the pertussis component in mice. The loss is evident when the amount of the parapertussis component added is 25% of that of the pertussis component, while the influence of relatively lower amounts of parapertussis organisms is less striking.

The parapertussis component in these vaccines, amounting to 2–25% of the pertussis component, does not affect the protective power of the pertussis component in mice.

Because the international basic set of staphylococcus typing phages includes only one member of group IV—phage 42 D—the group is insufficiently characterized. This set of phages is therefore not suitable for typing bovine strains of Staph. aureus. The addition of several further group IV phages would remedy this deficiency.

Young men were immunized against cholera, typhoid, paratyphoid A, and paratyphoid B. Agglutinating antibodies were measured 3 weeks after completion of the immunization schedule. Two injections separated by a 4-week interval were found to be as efficient as three injections with 1-week intervals.

Intracutaneous immunization with one-fifth of the standard subcutaneous dose was just as efficient as the standard subcutaneous immunization and did not cause greater general or local reaction.

Immunization of men with various amounts of salmonella antigens gave a linear relationship between the logarithm of the dose and the logarithm of the titres of the antibodies produced. No secondary response was observed for any of the doses used. These doses of salmonella vaccine did not interfere with or stimulate simultaneous primary or secondary vaccination with tetanus and diphtheria vaccine.

By the negative staining technique both Bittner and influenza viruses are pleomorphic and have similar fringed surfaces. The present study revealed that Bittner virus had one characteristic form consisting of a head approximately 1000 Å. in diameter and a tail up to 3000 Å. long. On storage at −20° C. Bittner virus broke down to reveal a round internal component of 750 Å. diameter. Influenza virus did not break down on storage at −20° C. but a small number of spontaneously disrupted particles revealed that the internal component was in the form of a coil. The circular internal component of Bittner virus is presumed to be spherical and corresponds to the previously described type A particles as seen by negative staining. The complete enveloped particle corresponds to the type B particle of thin sectioning. It is suggested that the thinly sectioned mature type B particle may be a degenerate form of the so-called immature type B particle. In addition, it is suggested that certain murine RNA tumour viruses may have a morphology distinctive to them.

A survey of mild respiratory disease in a primary school was undertaken over a 2-year period to determine which of the newer respiratory viruses were responsible for these illnesses.

The over-all isolation rate was low but a wide variety of viral agents was isolated.

None of these caused epidemics but it is suggested they may be the cause of a low but constant absentee-rate throughout the year.

Trials of aqueous and oil adjuvant vaccines in young adult volunteers showed that severe local reactions were rare. However, the incidence of minor symptoms was too high for a vaccine which requires to be administered repeatedly. In contradistinction to some reports, systemic and allergic reactions did not constitute a problem.

In trials with polyvalent commercial influenza vaccines the antibody responses to oil-adjuvant vaccine persisted longer and were often higher. Antibody conversion was poor after all vaccines and delayed after adjuvant.

1. The methods used for clearing a vaccine substrain of 17 D yellow fever virus of contaminant avian leucosis viruses are described.

2. Tests in animals and human subjects showed that the characteristics of the virus remained unchanged.

Impression plates from initially clean horizontal surfaces and floor areas in surgical wards showed a rapid accumulation of bacteria, mainly micrococci, which reached a fluctuating equilibrium after about 24 h. A later increase in bacterial contamination (mainly with aerobic sporing bacilli) to a higher equilibrium level after about 14 days occurred on uncleaned areas. Walls, even if left unwashed, acquired very few bacteria, but many were deposited locally when the wall was touched by a subject whose skin carried large numbers of staphylococci; moist exposed plaster was also heavily contaminated.

Regular use of a disinfectant (‘Sudol’ 1 in 100) in cleaning a ward floor did not reduce the equilibrium level of bacteria on the floor.

The transfer of staphylococci from contaminated to clean areas on the soles of shoes was demonstrated; the use of tacky and disinfectant mats did not appreciably reduce the transfer of bacteria by this route.

Staphylococci deposited on a wall by a disperser were shown to be transferred from the contaminated area of wall to the hands of another subject who did not previously carry the organism; this subject was shown to transfer the staphylo-coccus to a wall which he touched.

Attempts to redisperse by air movement Staph. aureus which had been shed by a disperser or by a contaminated blanket on to the floor surfaces had little effect; neither blowing with a hair dryer nor brisk exercise appeared to lift any of the staphylococci from a vinyl surface, and only small numbers were lifted by these measures from a terrazzo surface.

The hazards of infection from the inanimate environment are discussed.

A serum neutralization test was used to determine the incidence of rinderpest antibodies in populations of blue wildebeest (Connochaetes taurinus albojubatus Thomas) occurring in the Serengeti-Mara districts of N. Tanzania and S. Kenya. By correlating the age of animals at the time of shooting with the presence or absence of antibodies it was possible to outline the course of rinderpest in these animals over the period 1961–7.

Serengeti migrant wildebeest were extensively infected in 1961, but not in 1962 or any subsequent year. No samples have been collected from this group since mid-1966. Kirawira resident wildebeest were last infected in 1961 according to samples collected in February 1967. Two of 13 animals born into the Mara resident population in late 1961 or early 1962 were found to possess antibodies, together with a high proportion (74%) of animals born in early 1961. This finding was considered indicative of a rinderpest epizootic in this group in the terminal weeks of 1961. No subsequent infection occurred in Mara wildebeest between 1962 and March 1966. Ngorongoro resident wildebeest were infected in the second half of 1962 but have remained free of rinderpest from 1963 until at least April 1966.

The findings of the present survey were compared and contrasted with results of a similar study carried out some 2 to 3 years previously.

Field strains of bovine rinderpest virus were isolated from the Loliondo district of N. Tanzania in November 1965 and March 1966. Serum samples from buffalo, eland, impala, warthog, and resident wildebeest which inhabited areas adjoining the two outbreaks failed to provide evidence of any recent epizootic in game animals. Circumstantial evidence indicated that the virus could have persisted in the Loliondo area since 1961. Two resident wildebeest born in 1963 and 1964 respectively, were thought to have been infected during a period when the disease went unrecognised. Serengeti migrant wildebeest were not found to have been infected after a period of potential contact with sick cattle in March 1966.

Formalin-inactivated polio vaccine has been used in the Netherlands since 1957. Within 3 years all children born in 1945 and later were offered vaccine. In the first years poliovaccine from different manufacturers were used. In 1961 a vaccine produced in the Netherlands by the ‘Rijks Instituut voor de Volksgezondheid’ (National Institute of Public Health) became available and in 1962 the poliomyelitis components were incorporated in a quadruple vaccine, which contains 15 Lf diphtheria, 5 Lf tetanus toxoid and 16 × 109Bordetella pertussis organisms in addition to the three polio components. As an adjuvant this quadruple vaccine contains 1·5 mg. aluminium phosphate per 1 ml. dose. For infants the schedule became three doses at ages 3, 4 and 5 months respectively, followed by a booster dose at the end of the first year. The over-all acceptance rate can be estimated at almost 90% of those eligible, but there were pockets in the population with lower rates.

Since 1924 poliomyelitis has been a notifiable disease. During and after the last World War major epidemics occurred.

The poliomyelitis morbidity rates in the 8 post-vaccination years 1958–65 were compared with those from two preceding 4-year periods 1950–3 and 1954–7. In the 1–4-year-old children, who presented the most vulnerable age group, paralytic poliomyelitis was reduced by about 97 % and in the other age groups this percentage was slightly less. The over-all reduction was 96 %. Comparison of the morbidity rates of non-vaccinated persons in 1958–65 with the rates from 1950–3 and 1954–7 gave an impression of the extent of the herd immunity. These rates were reduced 70–80 % in the children under 15 years and 90–95 % in those over this age. The individual protection given to the vaccinated was calculated from the morbidity rates in non-vaccinated, incompletely and fully vaccinated persons in the 1958–65 period. The reduction of morbidity was 90–95% for children of 1–14 years who got three doses or more and about 85 % for those who had only 1 or 2 doses. Fully vaccinated children, who are profiting from both individual protection and herd immunity, showed a reduction of 97–99 %.

From the data presented it is concluded that vaccination with inactivated poliomyelitis vaccine can provide very effective protection for the individual and the community provided that a vaccine of good quality is used and the rate of acceptance is 75 % or better.

Nasal, perineal, axillary and hand swabs collected from 361 patients immediately before operation were examined for Staphylococcus aureus.

The organism was isolated more often from all three skin sites in nasal carriers of Staph. aureus than in non-carriers.

Twelve per cent of the patients, and 4 % of those with negative nose swabs were perineal carriers. Two per cent were heavy perineal carriers of Staph. aureus strains which could not be isolated by direct culture from a nasal swab. Staphylococcal strains from these heavy, independent, perineal carriers were more often resistant to tetracycline than were strains from nasal carriers.

Nose, throat and finger carriage of Staphylococcus aureus was investigated in a series of random samples from a normal European population.

No evidence for a seasonal trend in carriage was found but the intersample variation between successive random samples was obtained. The mean nasal carrier rate was 29 % with a standard deviation of 7 %.

No association was found between nasal or throat carriage of staphylococci and stay in hospital or antibiotic therapy but respondents with penicillin-resistant staphylococci in the nose had skin infections more frequently than those with penicillin-sensitive strains.

Evidence was obtained for a family, perhaps genetic, ‘predisposition’ to carry staphylococci in the nose.

A broad division of the opportunist mycobacteria has been defined under the name of ‘dysgonic nonchromogens’. The classification was attempted of 68 strains isolated from man in England and Wales, of which 54 at least appeared to be clinically significant. The means used were chiefly drug sensitivity, arylsulphatase activity, specific agglutination, lipid analysis and pathogenicity tests on fowls. On the results, a new definition is proposed for the species M. avium, extending beyond the boundaries of pathogenicity for birds, and a scheme put forward for its division into two types. In addition, two provisional new species and a group of ‘para-avian’ bacilli have been recognized and defined. The remaining 16 strains included six with ‘Battey’ serotypes but otherwise could not be classified. The need for standardization of fowl tests has been noted together with their diminished importance in the field of classification with the emergence of new in vitro methods of examination.