Fifteen healthy volunteers were given three weekly subcutaneous injections of a new polyvalent Pseudomonas aeruginosa vaccine (PEV-01). Four doses – 1·0 RHD (manufacturer's recommended human dose), 0·75 RHD, 0·5 RHD and 0·1 RHD – were used in separate groups of volunteers. Blood samples taken before each of the injections and one taken 7 days after the last injection were examined for immune response to the vaccine and for possible adverse clinical, biochemical and haematological effects.

Raised titres of antibody in serum of volunteers given 0·5–1·0 RHD vaccine were shown, often by the seventh day, in passive haemagglutination tests against all of the 16 serotypes of Ps. aeruginosa represented in the vaccine; serum from volunteers who received 0·1 RHD usually showed a reduced antibody titre. Tests of mouse protection by serum against intraperitoneal challenge with Ps. aeruginosa P14 showed increased titres of mouse protective antibody in the blood of volunteers given 1·0, 0·75 or 0·5 RHD of vaccine but a reduced mouse-protective titre in two out of three sera from volunteers given 0·1 RHD vaccine. There was a suggestion of enhanced phagocytic ingestion and intracellular killing of two strains of Ps. aeruginosa by the blood of vaccinated volunteers, and more definite enhancement of ingestion of inert latex particles, which were less well ingested than were the bacterial cells by phagocytes from unvaccinated volunteers.

Apart from slight or moderate local reactions and a transient rise of temperature in some volunteers, there were no clinical, biochemical or haematological abnormalities in the vaccinated volunteers.

A longitudinal, virological and serological study of pigs in two herds with respiratory disease showed that infection by porcine cytomegalovirus (PCMV) was universal in both.

Virus excretion usually began when piglets were between 3 and 6 weeks of age and reached a maximum between 5 and 8 weeks; it was usually no longer detectable at 11–12 weeks. Antibody demonstrable in indirect immunofluorescence (IIF) tests was present to moderate or high titre in all piglets at 2–3 weeks. This was presumed to be maternal in origin as it declined in titre between 2–3 and 5–6 weeks. After this fall the majority of piglets showed seroconversion as a result of virus infection. One group of 12 pigs in which infection occurred earlier than usual showed a very poor antibody response, which, nevertheless, persisted through to week 27.

The findings are discussed with relation to porcine atrophic rhinitis and cytomegalovirus infection in other species.

Normal non-irradiated McCoy cell cultures provide a sensitive and reproducible method for the isolation of oculo-genital strains of chlamydia A directly from human secretions and for laboratory studies with these agents. Since September 1973, chlamydia have been isolated from 175 of 562 women (32·1%) attending venereal disease clinics. Freshly isolated and low passage strains have been used to determine the importance of centrifugation, constitution and pH of the tissue culture medium, and the temperature of incubation in controlling the efficiency of plating in the method.

We report the first large-scale outbreak of echovirus 19 infection. It occurred in the north-east of England during the summer and autumn of 1974. The virus was isolated from 268 patients in the region. The infection spread from the urban to more rural areas, reaching a peak in mid-August. Males were affected more often than females in the ratio 1·6:1. Half of the patients were under eight years of age, relatively few were over 35 years. Aseptic meningitis and upper respiratory infections were the commonest presentations, though a wide range of other diseases occurred including gastroenteritis, myalgia, pericarditis, undifferentiated pyrexia, rashes and a syndrome analagous to bacteraemic shock. There was no evidence that the pattern or severity of the disease changed during the outbreak. Infants under the age of six months were more seriously affected than older children and adults. All patients except one made an uneventful recovery. Of the routine tissue culture cells HEp2 and HeLa were by far the most satisfactory for virus isolation.

The serological examination of over 900 rhinovirus strains isolated in Britain over a 10-year period has demonstrated a wide variety of different serotypes. Their seasonal and temporal distribution are described and discussed.

The well known cryoprotective additives glucose, sucrose, glycerol, dimethyl sulphoxide, polyvinylpyrrolidone, dextran and ammonium acetate have been found to prevent inactivation of T4Bo phage frozen in sodium bromide solutions. Their protective effects in this experimental system could not be accounted for by a colligative mechanism. It is proposed that they may act by modifying the structure of the unfrozen aqueous phase rather than by direct interaction with the phage.

A procedure for combining evidence from different biological assays is shown to be equivalent both to generalized least-squares and to maximum-likelihood estimation. By appropriate nesting of hypotheses, the likelihood function can be used to test the agreement between the assays and to obtain probability limits for the combined estimate of potency. The properties of these limits are examined, with particular reference to the situation, unusual but not impossible in practice, in which the values of relative potency that they define consist of several disjoint segments instead of a single interval. The connexion with general theory of estimating linear functional relations is pointed out.

A single intranasal dose of 107.0 EID50 recombinant WRL 105 strain live attenuated influenza vaccine was administered intranasally to 193 volunteers either as nose drops or by one of three spray devices which produced sprays of differing physical characteristics. In volunteers with homologous haemagglutinating inhibiting antibody titres of ⋜ 20 before vaccination, seroconversion rates varied widely from 80% following the administration of drops to 71%, 57% and 28% with the three spray devices.

In the week following vaccination 16 (22%) of 74 volunteers who were found to show a fourfold or greater antibody response took analgesics to control symptoms in comparison with 4 (7%) of 58 volunteers who exhibited no sero-logical response to vaccination (P < 0.05). However, neither the occurrence of upper respiratory nor systemic symptoms were significantly different in these two groups and the degree of attenuation of the recombinant WRL 105 strain appears to be acceptable for future use.

‘Mention of a trademark or a proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture, and does not imply its approval to the exclusion of other products that may also be suitable.’

Non-immunized, vaccinated, and recovered cattle were inoculated intranasally with various doses of foot-and-mouth disease virus. Samples of oesophageal-pharyngeal (OP) fluid were taken periodically for up to 7 days after inoculation and virus titres of these samples were plotted as pharyngeal virus growth curves.

In non-immunized cattle, the length of the lag period and of the growth period were inversely proportional to the dose of virus given. Maximum titres were observed when clinical signs were first detected. Three of the 10 cattle studied had virus growth rates that were lower than rates of others given the same dose of virus, and clinical signs appeared later than expected in these three cattle.

Cattle vaccinated with an inactivated virus oil-adjuvant vaccine had pharyngeal virus growth curves that were similar to those obtained from non-immunized cattle for 30 h. after inoculation. Titres of virus in OP fluid samples taken 2–7 days after inoculation were substantially lower in cattle with a high pre-exposure serum mouse protection index than titres from partly-immunized or non-immunized cattle.

Nine of 14 recovered cattle had detectable but reduced virus growth after intranasal inoculation with homologous virus. Five recovered cattle inoculated with heterologous virus reacted similarly to non-immunized animals.