Studies in man with a cold-recombinant live influenza B virus vaccine

A cold recombinant live influenza B virus vaccine was tested in man. In comparison to a placebo, reactogenicity attributable to virus infection was slight or moderate. No revertant viruses were shed, and there was no evidence of transmission to the placebo group who were housed in close contact with the vaccinees. Serological responses to initial inoculation were moderate; 60% of vaccinees showing twofold increases in serum hemagglutination inhibition (HAI) titers gave a geometric mean titer (GMT) of 1:13. Three weeks after the first vaccination, both the vaccine and the placebo group were revaccinated with homologous live virus vaccine. The group previously given vaccine was resistant to reinfection as judged from clinical reactions and virus shedding and the GMT increased only slightly to 1:16.3. In contrast, the former placebo group responded; mild symptoms were seen, the majority shed viruses and 50% showed twofold increases in serum HAI titers to a geometric mean titer of 1:17.4.

Studies with some influenza B viruses in cell cultures, hamsters and hamster tracheal organ cultures

Six influenza B virus strains and one recombinant vaccine strain have been compared in cell cultures, hamsters and in hamster tracheal organ cultures. In cell cultures all strains plaque well with or without trypsin. All strains are restricted in growth above 38 degrees C. The cold adapted attenuated virus, influenza B/AA/1/66, and a cold recombinant, RB77, are also restricted in growth above 37 degrees C and thus have a temperature marker. In hamsters influenza B viruses, except strain B/Lee, grow well in lungs and nasal tissues. Small differences were seen between wild type viruses and the cold adapted irus and its recombinants which may serve as additional markers for attenuation.

Studies with a cold-recombinant A/Victoria/3/75 (H3N2) virus. II. Evaluation in adult volunteers

A cold-recombinant influenza A virus, CR 22, derived from A/Ann Arbor/6/60 (H2N2) cold-adapted virus and A/Victoria/3/75 (H3N2) wild-type virus, was tested in adult volunteers. CR 22 induced only low-grade clinical reactions in volunteers who had low titers of serum antibodies. Virus could be reisolated from about one-third of the volunteers, but only at low titers. No revertant viruses were found, and there was no evidence for transmission of virus to unvaccinated volunteers housed in the close contact with the vaccinees. A high proportion of the volunteers seroconverted, and the mean titers of serum antibody after immunization suggest that a high degree of protection is induced by vaccination with liver CR 22 virus.

Studies with a cold-recombinant A/Victoria/3/75 (H3N2) virus. I. biologic, genetic, and biochemical characterization

A cold-recombinant virus CR 22, was derived from an attenuated cold-adapted parent strain. A/Ann Arbor/6/60 (H2N2), and a wild-type parent strain, A/Victoria/3/75 (H3N2). Antigenic analysis showed that CR 22 possesses the hemagglutinin and neruaminidase surface antigens derived from the A/Victoria/3/75 (H3N2) parent. From studies of virus-induced polypeptides using polyacrylamide gel electrophoresis, it was deduced that a polymerase protein, P1, is coded and by an RNA segment derived from the wild-type parent; all other genetic elements are derived from the attenuated parent. The attenuated parent and the recombinant CR 22 both possess temperature-sensitive (ts) lesions, evident by restriction of multiplication in fertile chicken eggs or in Madin-Darby canine kidney cell cultures at greater than or equal to 38 C. Genetic analysis of CR 22 by complementation tests using Hong Kong and Wilson Smith neurotropic ts mutants gave evidence for a ts lesion in the genetic elements coding for complementary RNA.

Studies in man with cold-recombinant influenza virus (H1N1) live vaccines

Two cold-recombinant influenza A (H1N1) viruses were tested in several groups of human volunteers. Only minor clinical symptoms were seen and no febrile reactions occurred. With serologically primed individuals virus shedding was low, but a high proportion showed rises in serum antibody levels after vaccination and mean titres were high. With serologically unprimed volunteers shedding was high, about 75% yielding viruses but only at low titres and for a short duration. No revertant viruses were found and there was no evidence of transmission to potentially susceptible individuals housed in close contact to the vaccinees. Serum antibody responses with unprimed volunteers were, however, low. Only about one half showed increases in serum antibody titres after vaccination and mean titres were low. Nevertheless, challenge with live attenuated virus indicated a high degree of protection based on virological evidence of infection.

The structural and infected cell polypeptides of influenza B virus

Structural and virus-induced infected cell polypeptides of several strains of influenza B virus were examined by high resolution polyacrylamide gel electrophoresis and shown to be directly analogous to those of the influenza A viruses. Eight structural polypeptides, P1, P2, P3, HA1, HA2, NA, NP and M were observed in purified virus and at least two additional polypeptides, HA and NS could be detected in infected MDCK cells. The three P proteins plus NP were shown to be associated with RNA-dependent RNA polymerase activity and HA, HA1, HA2 and NA were shown to be glycosylated. Like the influenza A viruses, migrational differences of some of the infected cell polypeptides could be observed between different B strains. Investigation of a time course of virus replication failed to show any temporal control of protein synthesis in the infected cell.

Growth of some attenuated influenza viruses in hamster tracheal organ cultures

Hamster tracheal organ cultures were infected with different influenza viruses and the metabolic activity measured using a tetrazolium reduction assay. In addition, relative ciliary activity was observed, virus multiplication measured, and histological studies were made. The hamster organ cultures proved relatively simple to set up and were sensitive to infection with influenza viruses; and the tetrazolium reduction was a reliable objective measure of relative tissue damage correlating well with histological and virological findings as well as with visual assessment of ciliary activities.

Growth of some attenuated influenza A viruses in hamsters

The replication of three attenuated influenza viruses in SPF hamsters inoculated by aerosol was investigated. Strains A2-Eng, A2-Victoria, ts-1-[E] A2-Victoria recombinant, and the RIT 4050 strain all multiplied to high titers in hamster lungs and induced both primary and secondary serological responses. Recombinant strain, A/AA/6/60-A2-Vic (CR22) multiplied to lower titers in hamsters. Differences were observed between the infectivity of different strains for hamsters, the wild-type viruses A2-Eng and A2-Vic being the most infective.

Infection of the uterine cervix with Chlamydia trachomatis

For identification of those variables in the history and in the clinical and routine laboratory examination that are most likely to indicate infection of the uterine cervix with Chlamydia trachomatis, 284 women attending a venereal disease clinic were studied, were studied, of whom 58 (20.4%) yielded the organism from the cervix. Women with chlamydial cervical infection showed no distinctive symptoms. Although associations were found between the presence of C. trachomatis and cervical discontinuity, purulent cervical exudate, and inflammatory changes in cervical cytology, these signs were not pathognomonic of chlamydial infection since they were also seen in some women infected with other microorganisms. There was a significant relationship between the presence of antibodies, detected by immunofluorescence, and the recovery of C. trachomatis in cell culture. There were no associations between ethnic group, history of sexually transmitted disease, method of contraception, phase in the menstrual cycle, or numbers of sexual contacts and infection with C. trachomatis.

Simplified serological test for antibodies to Chlamydia trachomatis

Three-hundred sixty sera from unselected patients attending two London venereal disease clinics were examined by a microimmunofluorescence test. Eleven egg-grown serotypes of Chlamydia trachomatis and the so-called "fast" strain SA2(f) were used as antigens. Of the 360 sera tested, 119 (33%) reacted to a titer of 1:16 or above with at least one antigen. Of these positive sera, over 50% cross-reacted with all 12 serotypes, and 95.5% reacted with SA2(f) in addition to other antigenic types. It is suggested that SA2(f) could be used as a single antigen for preliminary screening of a large number of sera for the presence or absence of chlamydial antibody.

The lack of effect of ampicillin plus probenecid given for genital infections with Neisseria gonorrhoeae on associated infections with Chlamydia trachomatis

Forty-six men were successfully treated with a single oral dose of ampicillin (2 g) plus probenecid (1 g) for urethral infections with Neisseria gonorrhoeae. Chlamydia trachomatis was isolated from cultures of cells obtained from 11 of these men both before and after treatment; C. trachomatis was isolated from one man before but not after treatment and from three men after but not before treatment. No isolates were obtained from the remaining 31 men either before or after treatment. Of the 15 patients whose cultures yielded C. trachomatis, 12 developed postgonococcal urethritis; of the 31 patients from whose cultures no isolate was obtained, five developed postgonococcal urethritis. Of 44 women successfully treated with ampicillin plus probenecid for cervical infections with N. gonorrhoeae, 18 had C. trachomatis isolated from the cervix both before and after treatment. C. trachomatis was isolated from five women before but not after treatment and from two women after but not before treatment. No isolates were obtained from the remaining 19 women either before or after treatment. Thus ampicillin plus probencide in the dosage used rarely eliminated C. trachomatis from the genital tract of either men or women. Whereas men with a persisting chlamydial infection will probably develop postgonococcal urethritis and thus receive appropriate treatment, such an infection in women is not likely to be suspected unless attempts are made to isolate C. trachomatis.

Chlamydial infection of the male urethra

Urethral specimens from 477 men were collected with endourethral swabs and examined for Chlamydia trachomatis by cell culture on McCoy cells pretreated with idoxuridine. Of these men, 141 had gonococcal urethritis, 262 non-gonococcal urethritis (NGU), and 74 showed no evidence of urethritis. Of 118 men with heterosexually acquired gonococcal urethritis, thirty (25 per cent.), and of 23 men with homosexually acquired gonococcal urethritis, five (22 per cent.), yielded C. trachomatis from the urethra. Urethral specimens from 240 heterosexual men with NGU were examined, and 118 (49 per cent.) yielded C. trachomatis. Of these 240 men, 140 gave a past history of gonococcal or nongonococcal urethritis and 67 (48 per cent.) of these were positive for C. trachomatis; no past history was given by 100 men, of whom 51 were positive for C. trachomatis. Of the 240 heterosexual men with NGU, 81 had had symptoms for 7 days or more before examination, of whom 48 (59 per cent.) yielded isolates of C. trachomatis, and 145 had had symptoms for less than 7 days, of whom 59 (41 per cent.) yielded isolates. Of fourteen asymptomatic men, three were positive for C. trachomatis. Of 22 homosexual men with NGU, seven (32 per cent.) yielded C. trachomatis. C. trachomatis was recovered from the urethra in three (5 per cent.) of sixty heterosexual men without urethritis, and none of fourteen homosexual men without urethritis yielded C. trachomatis.

Laboratory procedures for the isolation of chlamydia trachomatis from the human genital tract

The technique of isolating Chlamydia trachomatis from the human gential tract by centrifuging clinical specimens on to cell monolayers with subsequent incubation has been improved and simplified. Gentamicin in the media was found to be superior to streptomycin in reducing bacterial contamination of specimens. The infectivity of chlamydial suspensions of laboratory cultured material was significantly reduced by storage at +4 degrees C for more than 48 hours, and by immediate freezing to -70 degrees C. When compared with immediate processing of the specimens, freezing to -70 degrees C was found to reduce the isolation rate of C.trachomatis from men with non-gonococcal urethritis (NGU) by approximately 20%. McCoy cells pretreated with idoxuridine were compared with irradiated McCoy cells for the isolation of C. trachomatis from clinical specimens. There was no significant difference in sensitivity between the two systems, but the former is considerably simpler. The effect of the centrifugal force used for inoculating specimens on to the cell monolayers on the isolation rate of C. trachomatis was studied in groups of men with NGU. Maximal isolation rates were obtained with forces of about 3000 G, which were not significantly raised by further increasing the force used. It is suggested that the isolation of C. trachomatis from the genital tract is now well within the capacity of any laboratory equipped with simple cell culture facilities.

Minocycline in the treatment of nongonococcal urethritis: its effect on Chlamydia trachomatis

The effect of minocycline on nongonococcal urethritis (NGU) was investigated, with particular reference to its action against Chlamydia trachomatis. Preliminary laboratory studies showed that the drug was active against a laboratory chlamydial strain (Lb4f) in vitro. A group of 133 men with first attacks of NGU was then treated with minocycline, 100 mg twice daily for 3 weeks. Isolates of C trachomatis were obtained from 33 of these men before treatment; all of them gave negative results on cell culture after therapy. Of the 133 patients, 119 (90%) had symptoms on their first attendance, but after one week's treatment only 16 of the 133 (12%) and after 3 weeks 6 of the 133 (5%) had symptoms. All 133 men had demonstrable urethritis initially; by the end of the first week of treatment only 43 of the 133 (32%) and by the end of the third week 32 of the 133 (24%) had evidence of urethritis. There were no differences in clinical response between the Chlamydia-positive and Chlamydia-negative groups. A group of 24 female sexual contacts of men with NGU yielded C trachomatis on cell culture. After 3 weeks' therapy with minocycline all these women gave negative results on cell culture. It is concluded that minocycline is a useful addition to existing remedies for NGU. The future structure of treatment trials for NGU is discussed.

Infection with Chlamydia group A in men with urethritis due to Neisseria gonorrhoeae

Men with urethritis due to Neisseria gonorrhoeae were treated with gentamicin, which is inactive against Chlamydia. Urethral specimens were collected before treatment and one and two weeks after treatment and cultured for Chlamydia in irradiated McCoy cells. The overall incidence of chlamydial infection was 15 of 44 (34%). All of 15 Chlamydia-positive men and 11 of 29 Chlamydia-negative men (38%) developed postogonococcal urethritis two weeks after treatment. Pre-treatment sera were examined by a complement fixation test and a simplified indirect fluorescent antibody (FA) test with a yolk sac-cultured antigen, strain SA2)f). Sera from all of 15 Chlamydia-positive men had titers of larger than or equal to 1:16 in the indirect FA test; 13 of 29 Chlamydia-negative men (45%) had positive tests. The complement fixation test was insensitive, detecting chlamydial antibodies in only one of 15 sera from Chlamydia-positive men. These results suggest that Chlamydia may cause many cases of postgonococcal urethritis.

The ribonucleic acid of infectious bronchitis virus

Analysis of the nucleic acid of infectious bronchitis virus by SDS polyacrylamide gel electrophoresis revealed an RNA of molecular weight 9.0 times 10-6 Daltons. The RNA was shown to have a sedimentation coefficient of 50.