Field trials were carried out on combined live influenza vaccine A2 and B in November and December, 1965. Febrile reactions were observed in 145 persons (1.31%) of 11.089 vaccinated. A local catarrhal sign was negligible. Antibody response to influenza vaccine A2 was shown by nine (64.0%) of 14 persons with low initial titers. No antibody response was observed to influenza vaccine B because of high initial antibody titers.
A small epidemic of influenza A2 occuured in Febraury and March, 1966. Coefficient of effectiveness was 1.14-1.28. Mean maximum fever of epidemic influenza was 37.81 and 37.95°C for the vaccinated and unvaccinated persons, respectively, and the mean number of absent days of infected persons was 1.97 and 2.38, respectively, Ratio of mean absend days of the unvaccinated to vaccinated persons was 1.10-1.42. Ratio of mean absent rate of the unvaccinated control to vaccinated person against influenza was 1.3-1.9. Discussion was made on preferability of using this ratio to evaluate the effect of influenza vaccine.

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A small-scale trial of an attenuated type 3 poliovirus vaccine prepared with the USOL-D bac strain was carried out as a part of the collaborative study under the WHO's auspices.
In two closed institutions 26 children 5 to 13 months of age who had no history of anti-polio vaccination were administered with the vaccine, and 10 children of similar ages were left unvaccinated as room contacts. Of all the children, 21 vaccinees and 5 contacts had no circulating antibody against polioviruses. Most of the children in one institution (Infant Home H) excreted type 2 adenovirus in stools before or during the trial. No viral agent was isolated from pre-trial stools collected in the other institution (Infant Home B).
Inoculated with a single dose of the vaccine containing10^5.8 TCD₅₀ of the virus, the vaccinees in both institutions excreted considerably large amounts of type 3 poliovirus for long periods. One child in Infant Home B showed only transient excrection of the minimal detectable amount of virus on day 8. In Infant Home H the longest duration of virus excretion was 41 days with an average excretion period of 33.6 days, while in Infant Home B the longest duration of excretion was not less than 85 days with an average of 61.4 days. There was, however, no such great difference in the average of the maximal virus content per gram of stool of individual children between the two infant homes. This average was 10^7.4 TCD₅₀ in the H institution and 10^7.1 TCD₅₀ in the B. Stools of the contact children were examined only in Infant Homes H, where only one contact child excreted a small amount of virus on day 6.
Circulating antibody response was good in all the vaccinees, except the one mentioned above in Infant Home B. This child and three contacts of Infant Home H, including the one mentioned above, showed no rise of circulating antibody. The contacts of Infant Home B were fed Sabin types 1 and 2 divalent vaccine one week after the commencement of the trial, but they showed only type 3 antibody response. This may indicate that efficient contact infection with the vaccine virus took place during the first week of the trial.
Reversion of rct/40 character of virus progeny was observed rather early, and 45per cent of the isolates investigated was positive for rct/40 character, while only 14per cent was negative. The incidence of reversion appeared irregularly in individual children. Some children excreted rct/40^± of ract/40⁺ virus early and again excreated rct/40^- virus later.
The results obtained indicated that the USOL-D bac virus multiplied well in the gut of children, who showed a good antibody response, although it was genetically unstable. Efficient contact infection was observed in one institution where children were in close contact with one another in a play-room. Contact infection was almost completely prevented in the other institution where children were kept in bed.
The USOL-D bac virus was discussed for suitability as a candidate for a more acceptable type 3 poliovirus vaccine strain, in comparison with the Sabin type 3 Leon 12a₁b virus.

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Morphological change of a goat pneumonitis (GP) strain of Chlamydia psittaci in L cell monolayers induced by penicillin were investigated by electron microscopy. When the drug was added simultaneously with GP to the cell culture, its minimal inhibitory dose was estimated to be 1μg (1.6 units) per ml of medium. Penicillin interefered with the growth cycle of the psittacosis organism at a concentration higher than 1μg/ml by producing enlarged initial bodies 3 to 5μ in diameter. The abnormally enlarged initial bodies did multiply as such to some extent, but did not develop in to infective elementary bodies in the presence of an inhibitory dose of penicillin.
In the presence of a small dose of penicillin, ranging from 0.05 to 0.1μg/ml, an excessive cytoplasmic membrane was formed within the enlarged initial bodies 15 hours or more after the onset of infection. At that time were produced a number of irregular-shaped “miniature initial bodies” and small empty vesicles. The miniature initial bodies had been liberated from the initial bodies by a buddinglike process.
Free miniature initial bodies did not develop further. In the presence of a smaller dose of penicillin, ranging from 0.025 to 0.5μg/ml, clusters of electron-dense granules were formed within the maturing intermediate forms of the psittacosis organism. They were never found in the control intermediate forms grown in penicillin-free medium. The biochemical nature of those granules is not known at the moment.

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The effect and mechanism of the non-ionic detergent, polyethylene sorbitan mono-oleate (Tween 80), on Japanese encephalitis virus (JEV) was examined and following results were obatined.
1. Owing to the action of Tween 80 (0.01v/v%), JEV reduced remarkably in immunogenicity. When Tween 80 was added to the virus fluid not less than 30 days after formalin inactivation, the virus did not lose its immunogenicity and the potency of vaccine was maintained stably.
2. The infectivity of the virus was reduced about 5 logs in four hours and almost completely lost in ten hours after Tween 80 (0.2v/v%) treatment at 30C.
3. Tnterated virus showed infectivity, hemagglutination (HA) and complement fixation (CF) activites in the fraction with a buoyant density of 1.24-1.26g/ml, while non-infectious HA and CF activites were detected with a buoyant density of 1.19g/ml.
On the other hand, Tween 80 treated virus had only non-infectious HA and CF activities in the fraction with a buoyant density of 1.17-1.19g/ml.
4. In gel diffusion test, the untreated virus showed two precipitation bands, while the Tween 80 treated virus presented at least three precipitation bands. Of the three precipitation bands, two were common to those of the untreated virus and one of the two which was situated near the antigen well and considered to be related with infectivity became fainter.
From these results, it is clarified that JEV was disrupted by few molecules of polyethylene oxide which is a component of Tween 80 and viral infectivity and immunogenicity was reduced remarkably, while its HA and CF activities were maintained.
The action of formalin seemed to play a first role and that of Tween 80 is supposed to be suppressed in proportion to the degree of formalin fixation.

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