Seronegative Children Research Articles

Poliomyelitis outbreak in South Africa, 1982. II. Laboratory and vaccine aspects

Between May and September 1982 an extensive epidemic of poliomyelitis occurred in Gazankulu in the north-eastern region of South Africa, with a total of 260 paralysed cases and 42 deaths. A three-part study was instituted, the first of which established the aetiological agent of the epidemic to be poliovirus type 1. This was determined initially by serology and later by isolation of the virus, chiefly from stool specimens. The potency of the tri valent oral polio vaccine manufactured at the National Institute for Virology, was evaluated in the second study by in vitro potency testing of samples recalled from the epidemic areas and also in vivo by determining the serological response of seronegative children immunized with fresh vaccine. Nearly half of the vaccine samples withdrawn from the field had sub-optimal titres whereas fresh vaccine produced a very satisfactory serological response. In order to plan immunization rationally, the third study, namely the determination of the immune status of the various populations throughout the country was instituted. This involved both serology, using a neutralization test on randomly collected sera and also an analysis of patient history and health card documentation. With the exception of the urban black area (Soweto), which had high levels of immunity both serologically (75%) and on history, other areas examined had poorer levels of immunity of approximately 52% on serological testing and 57% on history. It is clear that the epidemic was multifactorial in origin, with fall-offs in the level of immunization and evidence of breaks in the cold chain being the major factors.

IMMUNOGENICITY AND SAFETY OF LIVE ORAL ATTENUATED BOVINE ROTAVIRUS VACCINE STRAIN RIT 4237 IN ADULTS AND YOUNG CHILDREN

A candidate oral live rotavirus vaccine, strain RIT 4237, of bovine origin, was tested for immunogenicity and safety in man. In adults the vaccine did not cause clinical symptoms, and a booster response in rotavirus serum antibodies was seen in 2/20 subjects. In seronegative young children one oral dose induced seroconversion to homologous virus in 15/17 (88%) children seronegative by enzyme immunoassay and in 13/19 (68%) children seronegative by a neutralisation assay. The vaccine did not produce gastrointestinal or constitutional symptoms in the children, nor did it cause rotavirus excretion in the stools. The results suggest that the RIT 4237 strain is a promising candidate for a vaccine against human rotavirus, and the vaccine-induced immunity against natural human rotavirus infection should be evaluated in future trials.

A search for congenital rubella in psychiatric day treatment, language and learning centres.

A search for previously undiagnosed congenital rubella (CR) was made on 672 children who had attended psychiatric day treatment, learning, and speech and language centres. This was done by observing the seroresponse of seronegative children to rubella vaccine, since 90% of patients with known CR who are seronegative fail to seroconvert to the vaccine. Of the 225 seronegative children 23 did not seroconvert after a single vaccination. Five of these failed to respond on revaccination. These five children had a high frequency of severe language and learning disability as well as frequent diagnoses of major CNS disorders. It is likely that a far greater number of children in the population studied had CR, since our methods identify only about 20% of those affected. Clinically, a specific diagnosis of CR is helpful in facilitating genetic counselling and in allowing the clinician to offer a more hopeful prognosis.

Antibody-dependent cell-mediated cytotoxicity against varicella-zoster virus-infected targets.

Antibody-dependent cell-mediated cytotoxicity (ADCC) against cryopreserved varicella-zoster virus-infected human foreskin fibroblasts was detected in a 51Cr release assay. Target cells, samples of seropositive or seronegative sera, and mononuclear cells obtained by Ficoll-Hypaque centrifugation of human peripheral blood were added to microtiter plate wells and allowed to incubate at 37 degrees C for 4 h. Fibroblasts infected for 48 to 96 h were susceptible to ADCC. Effector cells from seropositive and seronegative normal children were equally active in the assay. Antibody titers were determined by testing serial dilutions of sera in the ADCC assay. Zoster immune globulin had a titer of 204,800. Sera from 40 naturally seropositive individuals were compared by assays for ADCC and fluorescent antibody to membrane antigen. All sera that were negative by fluorescent antibody to membrane antigen (less than 2) were also negative by ADCC (less than 20). All sera that were positive by fluorescent antibody to membrane antigen were also positive by ADCC, but titers of individual sera were frequently 5 to 20 times higher in the ADCC assay.

Frequencies of Epstein-Barr virus-inducible IgM anti-IgG B lymphocytes in normal children and children with juvenile rheumatoid arthritis.

The relative frequencies of IgM antiIgG autoantibody (rheumatoid factor) producing cells induced by the polyclonal B cell activator Epstein-Barr virus were measured in peripheral blood lymphocyte cultures of normal children and patients with juvenile rheumatoid arthritis. The frequencies of rheumatoid factor precursor B cells in normal children were lower than adults, but higher than neonates. The frequency increased with the age of the donor. In seronegative children with the systemic-onset or pauciarticular-onset types of juvenile rheumatoid arthritis, the number of IgM antiIgG inducible B cells was not significantly different (P greater than 0.05) from age-matched controls. Patients with seropositive juvenile rheumatoid arthritis or seropositive adult rheumatoid arthritis had significantly higher IgM antiIgG precursor cell frequencies than age-matched normal subjects (P less than 0.01 and P less than 0.02, respectively). In contrast, the patients with seronegative polyarticular-onset juvenile rheumatoid arthritis had an average precursor frequency significantly lower than normal age-matched controls (P less than 0.05), analogous to results previously noted in adult seronegative rheumatoid arthritis. Thus, both children and adults with seronegative polyarticular rheumatoid arthritis had a deficiency in B cells that produce IgM antiIgG and that are induced by Epstein-Barr virus. This distinguished them from seropositive juvenile rheumatoid arthritis and rheumatoid arthritis patients, normal subjects, and patients with the pauciarticular-onset and systemic-onset types of seronegative juvenile rheumatoid arthritis.

Administration of a highly attenuated, live respiratory syncytial virus vaccine to adults and children.

A highly attenuated respiratory syncytial virus (RSV) experimental vaccine, RSV ts-2, was sequentially evaluated in adults, seropositive children, and finally, fully susceptible seronegative children. The vaccine was administered intranasally in doses ranging from 10(5.2) to 10(6.3) PFU/ml. In both adults and children, the vaccine proved to be poorly infectious. Although poor infectivity would not have been predicted from tissue culture studies of RSV ts-2 growth, the human experience closely parallels the experience in a series of animal models, including the chimpanzee. The poor infectivity of this RSV vaccine virus preparation suggests that the postulated defect in the RSV ts-2 fusion protein may be important in determining in vivo infectivity of RSV.

IgG and IgM rheumatoid factor in active seronegative nodular rheumatoid arthritis and in children with benign rheumatoid nodules.

Rheumatoid nodules in rheumatoid arthritis are usually associated with high levels of IgM rheumatoid factors and aggressive disease. IgM, IgG, and C3 have been identified in tissue sections of rheumatoid nodules, suggesting pathogenetic importance. The role of IgM and IgG rheumatoid factors in sero-negative RA is poorly understood. Seven patients with active seronegative RA and rheumatoid nodules and 10 seronegative children with the syndrome of benign rheumatoid nodules were studied for the presence of IgG and IgM rheumatoid factors by radioimmunoassay and for complement-fixing IgM rheumatoid factor by haemolytic assay. Elevated titres of hidden complement fixing IgM rheumatoid factor were found in 60 % of the patients with benign rheumatoid nodules studied but in none of the patients with active seronegative nodular RA. Serum IgG and IgM rheumatoid factor levels by radioimmunoassay and circulating immune complex levels in both groups were not significantly different from normal controls. These data suggest IgG and IgM rheumatoid factors do not participate in the pathogenesis of active seronegative rheumatoid arthritis with rheumatoid nodules.

Clinical and laboratory studies of combined live measles, mumps, and rubella vaccines using the RA 27/3 rubella virus.

AbstractEleven lots of combined bivalent and trivalent vaccines containing the measles (Moraten), mumps (Jeryl Lynn), and rubella (RA 2713) viruses gave satisfactory results in tests in initially seronegative children (measles, 493 children; mumps, 377; rubella, 586). There was no apparent suppression of antibody response against any of the viruses in the vaccines. The clinical reactions observed were mild and inconsequential. Substitution of the HPV 77-DE strain employed heretofore with the RA 27/3 is technically acceptable and offers the advantage of higher titer, slightly greater seroconversion rate, and more solid immunity against reinfection in nature.

Inactivated poliovaccine: adverse reactions and antibody responses.

Adverse reactions and antbody responses after inactivated poliovaccine were studied in 380 children. Fever reaction (greater than or equal to 37.5 degree C rectally) was recorded in 14% of children after the first poliovirus vaccination and in 19% after the second. Restlessness was reported in 15% and 14% of the chidren. Fever reaction exceeding 38.5 degree C was seen in 5% of the vaccines. Before the first vaccination at the age of six month 29% of the 48 children had antibodies against poliovirus type 1 and 2 and 43% against type 3. The first vaccination induced no significant changes in antibody titers. After the second vaccination antibody responses were low and 35%, 9%, and 35% remained seronegative to types 1, 2 and 3, respectively. After the third vaccination at the age of two years the respective geometric mean titers were 1:67, 1:335 and 1:48. No measurable antibodies were found to type 1 in 23%, to type 2 in 2%, and to type 3 in 10%. Only one child was triplenegative. All seronegative children were revaccinated and in all vaccinees a seroconversion ocurred two weeks after the booster dose. The combination of inactivated poliovaccine to DPT (Diphtheria, Tetanus, Pertussis) vaccine induced no significant change in poliovirus antibodies or in adverse reactions.

Immune responses to measles and smallpox vaccinations in malnourished children

Children with different levels of nutritional status were studied to determine their immune response to, and complications from, immunization with live measles vaccine and lyophilized smallpox vaccine. Two hundred forty-one children between the ages of 5 months and 9 years were examined to assess their nutritional status at the time of immunization. Sero-conversion was defined as a hemagglutination-inhibition titer to measles virus, of greater than or equal to 1:20 6 to 8 weeks after vaccination in initially sero-negative children. Of 111 initially sero-negative children 94% had an adequate immune response, shown by sero-conversion. Of 193 children without a smallpox vaccinationscar 97% were successfully immunized against smallpox. These rates of immune response were independent of age, sex, and nutritional status of the children. The geometric mean titer rise to measles immunization of groups, whose nutritional status was normal (greater than 90% of median weight for age), mildly (75 to 90%), moderately (60 to 75%), or severely (less than 60%) malnourished were 7.5, 8.8, 7.9, and 7.9, respectively. Malnutrition did not affect the children's ability to develop adequate immune response to measles of smallpox vaccine, and there were no major complications during the 8-week period of follow-up. Since measles is a very severe disease, which in malnourished children can carry a case fatality rate as high as 50%, malnutrition should be a prime indication for measles immunization, and certainly not a contraindication.

Transfer factor and cellular reactivity to varicella-zoster antigen in childhood leukemia

The present studies were designed to evaluate possible efficacy of specific human transfer factor (TF) in preventing or attenuating varicella-zoster (VZ) infection in children with acute lymphocytic leukemia (ALL). TF was prepared following leukapheresis of adult donors who were convalescing from chicken pox. Recipients were VZ seronegative children with ALL, 12 in remission and 3 in relapse; a single injection of TF was given equivalent to 10 8 lymphocytes per 7 kg body wt. The following VZ-specific parameters were measured: lymphocyte blastogenesis, cytotoxicity and leukocyte inhibitory factor (LIF) production, and indirect fluorescent and CF antibody titers. No patients in relapse converted immune response while 10 12 in remission developed positive reactivity in at least one assay of cell-mediated immunity (CMI); 3 12 were positive in all three parameters of CMI and 8 12 in two assays. Cytotoxicity was the most consistently positive test following TF administration. No patients developed VZ antibody. Seventeen months follow-up has demonstrated persistent cellular immunity.

Antibody-Dependent Cell-Mediated Cytotoxicity against Cells Infected with Respiratory Syncytial Virus: Characterization of in Vitro and in Vivo Properties

Abstract An in vitro 51Cr release assay for human antibody-dependent cell-mediated cytotoxicity (ADCC) against HeLa cells infected with respiratory syncytial virus (RSV) has been characterized by using leukophoresed and adherent cell-depleted adult lymphocytes. Lymphocytes from RSV seronegative children were also competent as effector cells. Sera from children with: 1) primary and recurrent natural RSV infections, or 2) live attenuated RSV vaccine infection were examined to characterize the behavior of ADCC antibody in vivo. After natural RSV infection ADCC antibody rose and fell more rapidly than neutralizing antibody. In two children undergoing primary RSV infection with attenuated vaccine, neutralizing antibody was formed in the absence of detectable ADCC antibody. The nonparallel behavior of ADCC and neutralizing antibodies suggests the heterogeneity of either the antigen involved or the mechanism of antibody production in the two antibody systems.

CONGENITAL RUBELLA DEAFNESS: A PREVENTABLE DISEASE

Summary Over a 4-year period (1972-75) an unselected sample of 568 children aged under 4 years attending the Nuffield Hearing and Speech Centre were tested for rubella antibody. Sensorineural deafness was subsequently diagnosed in 349 of these children, and 83 (24%) of this group had rubella antibody. In contrast, only 19 (9%) of the remaining 219 children in whom sensorineural deafness was excluded had rubella antibody. The seropositive and seronegative children with sensorineural deafness showed striking differences in family history, history of maternal rubella, adverse perinatal events, and presence of other defects. Congenital rubella is an important cause of deafness, and the rubella vaccination programme must be pursued more vigorously if this serious defect is to be prevented in the future.

Further Investigations of Live Respiratory Syncytial Virus Vaccine Administered Parenterally

SummaryFurther clinical tests were carried out of a live attenuated respiratory syncytial virus vaccine administered parenterally. Neutralization of respiratory syncytial virus by homologous human antibody was found to be a complement-dependent event and addition of guinea pig complement greatly increased antibody titers and the sensitivity of the test. Ninety-seven percent of 116 initially seronegative children developed antibody following vaccination and there was no evidence for contagious spread of the infection. Clinical reactions, if any, were mild and inconsequential. A small portion of initially seropositive persons appeared to develop antibody by booster effect and a portion of initially seronegative and seropositive persons developed detectable nasal antibody. Long-term follow-up failed to reveal any increase in severe respiratory disease in initially seronegative persons who were vaccinated. A very substantial reservoir of seronegative persons was found in the 7 to 47 month age group (35%) reve...

Live respiratory syncytial virus vaccine administered parenterally.

SummaryA unique live attenuated respiratory syncytial virus vaccine that is administered parenterally is described. Nineteen of 22 initially seronegative children, 7-32 months of age, developed homologous circulating neutralizing antibody against the virus and a portion were shown to have present demonstrable antibody in their nasal secretions. None of the children developed illness that could be ascribed to the vaccine, and there was no evident contagious spread of the vaccine virus to susceptible contacts. The vaccine is of considerable promise and trials to determine protective efficacy are being pursued. Seroepidemiologic investigations revealed that only 33 of 66 children 6-48 months of age and residing in an open population had detectable circulating neutralizing antibody against the virus.

Antibody responses following rubella immunization analyzed by HLA and ABO types

HLA typing was performed on 232 rubella seronegative (HAI antibody titer <8) children immunized with RA 27/3 vaccine. High convalescentphase geometric mean antibody titers were noted in children one to five years of age, in girls one to 12 years of age, in subjects with AB blood type and in vaccinees with HLA types B14 and BW22. Of nine children with rubella titers≧512, 44 percent had HLA type A28; in contrast, only eight percent of the total group had A28 HLA type. HLA-A2 was present in four, and HLA types B12 and BW17 were present in three of the six children in whom seroconversion did not occur. Fifteen of 37 sibling pairs had identical antibody responses; in contrast, only 18 percent of randomly paired children had titers identical to each other. Vaccine-related symptomatology could not be associated with any HLA type. The results of this study suggest that infection with and antibody response to RA 27/3 rubella vaccine is influenced by genetic factors, which include cellular membrane determinants.

Is Adult Immunization More Appropriate Than Immunization of Infants?

To the Editor: The report of Weibel et al. (Pediatrics 56:380, September 1975)concerning long-term antibody levels after monovalent or combined measles,mumps, and rubella virus vaccines presents numerous observations, but leaves one of the more interesting ones incompletely explored. Of particular interest to us is an apparent disparity in levels of rubella antibody five years after rubella immunization of seronegative children and adult women. Among 74 children followed up for duration and level of

LIVE PARAINFLUENZA TYPE 3 VACCINE IN CHILDREN

Clinical trials in young children of viral respiratory vaccines provide a model for determining viral and host factors in the control of primary infection. An attenuated parainfluenza 3 (para 3) vaccine was given intranasally (104-5 TCID50/dose) to 16 children ages 13 to 35 months-with 5 additional placebo inoculated controls studied for transmission and intercurrent illness. Prior natural para 3, as judged by prevaccination serum antibody, completely inhibited vaccine virus shedding and only 1/7 sero-positive children had an antibody rise. In contrast, 7/9 sero-negative children shed virus for up to 11 days after inoculation. All seronegatives had serum antibody responses by CF, HAI or plaque-neutralization tests. No nasal antibody responses were observed in 9 children (4 of whom had a serum antibody rise) tested. Mild afebrile respiratory illness was observed at the time of peak virus shedding, 8-9 days post inoculation, suggesting illness was a function of virus replication. Thus, multiple laboratory passages (4 in monkey kidney, 75 in eggs) did not sufficiently attenuate para 3 for seronegative children. In spite of symptomatic shedding in vaccinees no transmission to controls was observed. The duration of para 3 vaccine shedding in seronegatives was uniform with a mean of 9.4 days. This is similiar to shedding by seronegatives of attenuated respiratory syncytial virus, 10 days, and influenza, 8.6 days; and suggests a common host mechanism for terminating primary respiratory viral infection.

A comparative field trial of five measles vaccines produced in human diploid cell, MRC-5

Abstract Five batches of experimental measles vaccines were prepared with Biken-CAM, Schwarz, Sugiyama, Leningrade-16 and AIK-C strains in MRC-5 HDC. The rct40, T50 or neurovirulence for baby hamsters of these viruses adapted to HDC were not significantly changed but the neurovirulence of the Sugiyama virus for day-old hamsters was increased after passages in HDC. With the exception of the AIK-C strain the size of the plaques was increased by 20 passages of virus in MRC-5 cells. The experimental vaccines were evaluated clinically and serologically in a field trial in seronegative children in the Caspian Sea area north of Iran. It was found that: (a) the lowest clinical reactions were recorded for the AIK-C vaccine; (b) the seroconversion was high for all vaccines ranging between 95·5 and 100%; and (c) that the hemagglutination-inhibiting (HI) antibody titers of sera of the vaccinees ranged from 25·2 to 26·5.

Measles Immunization

As a result of a large outbreak of measles, measles hemagglutination inhibition (HI) titers were measured in 465 immunized children. Titers of less than 1:4 were found in 14.6% of children immunized at 12 months of age as compared to 5.2% of those immunized at 13 months of age or later. Measles antibody titers were higher in the mothers of seronegative children who had been immunized at 11 or 12 months of age than in the mothers of seroposotive children. Measles HI titers of 1:4 or more were present in 94% of children immunized at 13 months of age or later between 1962 and 1964. The findings suggest that vaccine failure and not waning antibody accounts for the majority of titers of less than 1:4 in immunized children. Reimmunization programs should be considered for those who were immunized before 13 months of age.