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W J Bellini

Publications and source records attributed to W J Bellini.

At least 55 records · Page 3Linked to original sources
PubMed1996

Comparative detection of measles-specific IgM in oral fluid and serum from children by an antibody-capture IgM EIA.

In vaccinated populations, the diagnosis of measles often requires laboratory confirmation. Serum tested by EIAs has proven sensitive and specific for diagnosing measles. For comparison of detection of measles-specific IgM in oral fluid and serum samples by an antibody-capture EIA, 163 Ethiopian infants who presented for routine measles vaccination were studied. Paired serum and oral fluid samples were collected before and 2 weeks after vaccination; 269 paired samples were adequate for analyses. Of the 104 serum samples that were IgM-positive, 95 (91%) of the paired oral fluid samples were IgM-positive. Of the 165 serum samples that were IgM-negative, 156 (95%) of the paired oral fluid samples were IgM-negative. The Pearson partial correlation coefficient for optical density readings from postvaccination oral fluid compared with serum was 0.81. Oral fluid appears to be an acceptable alternative to serum for measuring measles-specific IgM antibodies by an antibody-capture EIA.

Antibodies, Viral↗
PubMed1996

Measles vaccine effectiveness and duration of vaccine-induced immunity in the absence of boosting from exposure to measles virus.

BACKGROUND: It is unknown whether vaccine-induced immunity is lifelong in the absence of periodic exposure to measles virus. After 27 years of no known exposure to measles, an outbreak in Palau in 1993 offered the opportunity to study this issue and the measles vaccine effectiveness. METHODS: Household contacts of a sample of confirmed cases were interviewed for exposure, symptoms and vaccination status verified by records. Serum from symptomatic contacts was tested for measles antibodies. RESULTS: Among 78 contacts 4 of 5 (80%) unvaccinated, 4 of 35 (11%) 1-dose vaccine recipients and none of 38 (0%) > 1-dose recipients developed measles. Effectiveness of 1-dose vaccine was 86% (95% confidence interval, 60 to 95%). An additional dose significantly reduced the risk of measles (P = 0.048). Time since vaccination was not a significant risk factor for developing measles (relative risk, 1.6; 95% confidence interval, 0.3 to 9.4; persons vaccinated > 15 years ago vs. < 5 years ago). CONCLUSIONS: Similar to the estimates previously obtained in the area, measles vaccine effectiveness in Palau was lower than the estimates obtained in the US. A second dose of vaccine further reduced the risk for developing measles. We found no evidence that waning immunity was an important problem in this limited population with no known previous exposure to measles virus. The small number of vaccinated contacts precludes a definitive assessment.

Child↗
PubMed1996

An evaluation of measles revaccination among school-entry-aged children.

BACKGROUND: A two dose measles vaccination schedule is recommended routinely for all school-entry-aged children. We evaluated this recommendation by determining both measles antibody seroprevalence and the response to revaccination in seronegative children in this age group. METHODS: Children 4 to 6 years of age who had received a single dose of measles vaccine between the ages of 15 to 17 months were tested for measles antibody by using enzyme-linked immunosorbent assay (ELISA) microneutralization technique. Seronegative children were revaccinated and again tested for measles antibody (immunoglobulin M [IgM] and neutralizing). RESULTS: Of 679 children tested, 37 (5.4%) were seronegative. Seronegativity was not significantly associated with age, sex, race, age at initial vaccination, time since vaccination, or maternal year of birth. However, children mothers with a college degree were 12 times more likely to be seronegative than children of mothers who never attended college (P < .01). Of the 37 seronegative children, 36 seroconverted after revaccination--33 producing IgM measles antibody, suggestive of a primary immune response. The cost per seroconversion would have been an estimated $415 if all 679 children had been revaccinated. CONCLUSIONS: Revaccination reduces the pool of children who are susceptible to measles. Although the cost per seroconversion is high, a two-dose schedule should reduce the substantial costs of controlling measles out breaks by reducing the number of outbreaks.

Antibodies, Viral↗
PubMed1996

Measles antibody in vaccinated human immunodeficiency virus type 1-infected children.

OBJECTIVES: The goals of this study were to evaluate the proportion of previously vaccinated human immunodeficiency virus (HIV) type 1-infected children with detectable postvaccination measles antibody; to assess risk factors for vaccine failure; and to evaluate the response to reimmunization. METHODS: A total of 81 perinatally HIV-infected children receiving medical care in the Bronx, New York who had previously received measles vaccine were enrolled. The Centers for Disease Control and Prevention (CDC) HIV class, lymphocyte subsets, and measles antibody were determined upon enrollment. Additional data abstracted from medical records included dates and number of prior measles vaccinations and CDC HIV class at the time of vaccination. Measles antibody was determined by microneutralization enzyme-linked immunosorbent assay (ELISA). RESULTS: The median age at time of study was 42 months (range, 9 to 168 months). Overall, 58 (72%) subjects had detectable measles antibody (microneutralization ELISA titer > 1:5). Children studied within 1 year of vaccination were more likely to have detectable measles antibody than children evaluated more than 1 year after vaccination (83% vs 52%, P < .01). The proportion of children with detectable measles antibody was higher among children with no or moderate immunosuppression compared to those with severe immunosuppression when immune status was based on CD4%. Children vaccinated at 6 to 11 months of age appeared to have a higher proportion of detectable measles antibody than those who received a first measles vaccination after age 1. Only 1 (14%) of 7 previously vaccinated children who were seronegative or had very low titers experienced a four-fold rise in measles antibody when reimmunized. CONCLUSION: These results support current recommendations to vaccinate HIV-infected children against measles. The proportion of children with detectable measles antibody among vaccinated HIV-infected children is considerably lower than in vaccinated healthy children. HIV-infected children may respond better to measles vaccine when it is administered before the first birthday. From our limited data it appears that reimmunization of previously vaccinated HIV-infected children with moderate to severe immunosuppression does not result in an antibody recall response.

Adolescent↗
PubMed1995

Hypermutation of the phosphoprotein and altered mRNA editing in the hamster neurotropic strain of measles virus.

Sequence analysis of the nucleoprotein and phosphoprotein (P) genes of viruses in the hamster neurotropic lineage of measles virus revealed that the neurotropic variants are quite different from the Philadelphia 26 progenitor strain. In Vero cells persistently infected with the hamster neurotropic strain, predicted changes occur in 5.0% of the nucleoprotein and 8.1% of the P amino acids and some of these changes appear to affect the relative electrophoretic mobility of each protein. To evaluate one aspect of the viral polymerase complex containing these mutations, the distribution of P mRNA editing in each of the three strains was determined by both cloning and sequencing of polymerase chain reaction-amplified DNA fragments which included the editing site and by primer extension analysis of viral mRNA. Editing of P mRNA in the neurotropic strains shows a shift away from the single G insertion product to those with greater than 2 Gs inserted. The altered editing distribution has implications for the role of transcriptional regulation in measles virus persistence.

Animals↗
PubMed1995

Detection of measles virus RNA in urine specimens from vaccine recipients.

Analysis of urine specimens by using reverse transcriptase-PCR was evaluated as a rapid assay to identify individuals infected with measles virus. For the study, daily urine samples were obtained from either 15-month-old children or young adults following measles immunization. Overall, measles virus RNA was detected in 10 of 12 children during the 2-week sampling period. In some cases, measles virus RNA was detected as early as 1 day or as late as 14 days after vaccination. Measles virus RNA was also detected in the urine samples from all four of the young adults between 1 and 13 days after vaccination. This assay will enable continued studies of the shedding and transmission of measles virus and, it is hoped, will provide a rapid means to identify measles infection, especially in mild or asymptomatic cases.

Adult↗
PubMed1995

Localization of monoclonal antibody epitopes and functional domains in the hemagglutinin protein of measles virus.

The expression of chimeric proteins was performed for the localization of monoclonal antibody (MAb) epitopes and functional domains in the hemagglutinin (H) protein of measles virus. The fusion helper function of the H protein was ablated by a single amino acid substitution at residue 98. Loss of reactivity to MAb 79-XV-V17 and to MAbs 16-CD-11 and 80-II-B2 was attributed to substitutions between residues 211 and 291 and between 451 and 505, respectively. The 80-II-B2 MAb epitope also seemed to be within a domain required for hemadsorption and hemagglutination activities.

Antibodies, Monoclonal↗
PubMed1994

Restriction of fusion protein mRNA as a mechanism of measles virus persistence.

Vero cells persistently infected with the hamster neurotropic strain (HNT-PI) of measles virus are deficient in the release of extracellular virus and syncytia formation, suggesting that mutations occur within the viral envelope proteins. Nucleotide sequence comparisons indicated that the coding regions of the matrix (M) and fusion (F) genes of HNT-PI were relatively conserved compared with those of their lytic progenitor virus Philadelphia 26 (Ph26), whereas the hemagglutinin (H) gene differed by 4.2% at the amino acid level. Northern blot analyses demonstrated the predominance of bicistronic M/F transcripts in HNT-PI at a 5:1 ratio over F monocistronic mRNA. Accordingly, no F protein could be detected in the HNT-PI cell line, although both the M and H proteins were produced in amounts comparable to those of Ph26. When the Semliki Forest virus replicon was used, coexpression of the HNT-PI F and Ph26 H genes resulted in the formation of multinucleated syncytia in transfected Vero cell cultures. Since the HNT-PI F protein was fusogenic, the restriction of its monocistronic mRNA is postulated to be a contributing factor in the reduction of cell fusion and ultimately in the maintenance of the persistent infection.

Amino Acid Sequence↗
PubMed1994

Evolution of the nucleoprotein and matrix genes of wild-type strains of measles virus isolated from recent epidemics.

To characterize the genetic properties of currently circulating strains of wild-type measles viruses, we constructed and sequenced cDNA clones of the nucleoprotein (N) and matrix (M) genes of wild-type strains isolated between 1958 and 1989. The N and M genes of wild-type isolates from the prevaccine era (before 1964) were highly related to each other and to the N and M genes of a currently used measles vaccine strain, Moraten. The N and M genes of these viruses differed by no more than 0.5% at the nucleotide level. In contrast, the N and M genes of wild-type viruses isolated between 1977 and 1989 showed genetic drift, with the greatest amount of drift occurring in the viruses isolated from recent cases in the United States. Overall, the M genes were slightly more conserved at the nucleotide level (2.6% nucleotide, 3.3% amino acid) than the N genes (4.8% nucleotide, 3.4% amino acid). Alignment of the predicted protein sequences of the N genes revealed two regions of amino acid heterogeneity. The evolutionary patterns for the N and M genes suggested that the wild-type viruses isolated in the United States in 1989 were more related to wild-type viruses isolated in the United Kingdom between 1983 and 1988 than to viruses isolated in the United States in 1983.

Amino Acid Sequence↗
PubMed1994

Comparison of sequences of the H, F, and N coding genes of measles virus vaccine strains.

Many live-attenuated vaccines for measles virus have been developed using either the prototype Edmonston strain or other locally isolated measles strains. The attenuation methods used to develop these vaccines have differed in the type(s) of cell line(s) used, number of passages, and temperatures of incubation. To assess the extent of genetic diversity within vaccine strains and to determine the extent to which the varied passage histories may have affected the viruses, we conducted sequence analyses of the fusion, hemagglutinin, nucleoprotein, and matrix genes of Edmonston-derived and non-Edmonston-derived strains. Despite the diverse geographic origins of the vaccine viruses and the different attenuation methods used, there was remarkable sequence similarity among all strains examined. The sequences of all of the vaccine strains were very similar to the sequences of a low-passage seed of the original Edmonston strain. The most divergent sequences were from two of the non-Edmonston-derived vaccines: CAM-70, a vaccine developed from a Japanese wild-type virus, and S-191, which was developed in China.

Base Sequence↗
PubMed1994

Maternal immunity to measles and infant immunity at less than twelve months of age relative to maternal place of birth.

Sera from infants aged 5 to 11 months and from their mothers were used to investigate the level and duration of transplacentally derived measles antibody. The infants of foreign-born, inner-city mothers were more likely to have measles antibody and were less likely to get measles. Infants of foreign-born mothers, because they are less likely to respond to measles vaccine, may require different vaccine strategies than infants of mothers born in the United States.

Antibodies, Viral↗
PubMed1994

Disseminated measles infection after vaccination in a child with a congenital immunodeficiency.

An infant boy with a congenital immunodeficiency had fatal disseminated measles after administration of a live attenuated measles vaccine. This rare complication was confirmed with molecular virologic techniques. Although efforts to expand availability of vaccinations are critically important, caution is warranted in children with potentially severe immunologic dysfunction.

Failure to Thrive↗
PubMed1994

Antigenic analysis of current wild type and vaccine strains of measles virus.

The antigenic properties of vaccine and wild type strains of measles virus were compared. Serum specimens from vaccinated persons, persons infected during the prevaccine era, or mice experimentally vaccinated with the hemagglutinin (H) protein from vaccine virus neutralized vaccine virus and a wild type measles virus from 1989 equally well. In contrast, serum specimens from patients with recent measles virus infection and mice experimentally vaccinated with the H protein from the wild type virus from 1989 neutralized wild type virus with titers 4-8 times higher than those to vaccine virus. Several H protein-specific monoclonal antibodies could differentially recognize vaccine or wild type virus. These data show that the H proteins of the recent wild type viruses contain both conserved and new or modified antigenic determinants and are consistent with previous studies that described genetic drift in the H proteins of recent wild type viruses.

Animals↗
PubMed1994

Virology of measles virus.

Measles virus is the prototypic member of the Morbillivirus genus of the family Paramyxoviridae. The viral genomic RNA is single-stranded, nonsegmented, and of negative polarity and encodes six major structural proteins. The two viral transmembrane glycoproteins, the hemagglutinin and fusion proteins, are both required for virus-host cell membrane fusion, while attachment to host cells is mediated by the hemagglutinin. The human CD46 molecule has been identified as a cellular receptor for measles virus. Antibodies raised against either viral glycoprotein neutralize measles virus in vitro and protect against infection. Although measles virus remains a single serotype (monotypic), nucleotide sequence analyses have identified distinct lineages among recent wild type isolates. These genetic changes were manifested by detectable antigenic variation between vaccine and wild type viruses and at some point may influence strategies for control, elimination, and eventual eradication of measles virus.

Animals↗
PubMed1994

Measles immunity in HIV-infected children.

In a retrospective study, sera from 84 children of human immunodeficiency virus (HIV)-seropositive mothers (35 HIV-infected and 49 uninfected children) with a known date of receipt of measles, mumps, and rubella vaccine were tested for antibody to measles vaccine by an indirect enzyme immunoassay (EIA) method and/or microneutralization (NEUT). At the time of last measurement, 21/35 (60.0%) HIV-infected children remained seropositive by either EIA or NEUT. Forty seven of forty-nine (95.9%) uninfected children had evidence of measles antibody. Six HIV-infected children had a documented loss of antibody over time. The majority of HIV-infected children had antibody to measles vaccine virus, which in some cases decreased over time.

Antibodies, Viral↗
PubMed1993

Immunoglobulin M antibody response to measles virus following primary and secondary vaccination and natural virus infection.

The use of IgM antibody detection for the classification of the primary and secondary measles antibody response in persons following primary and secondary vaccination and natural measles virus infection was examined. Of 32 nonimmune children receiving primary measles vaccination, 31 (97%) developed IgM antibodies, consistent with a primary antibody response. Of 21 previously vaccinated children with low levels of preexisting IgG antibodies who responded to revaccination, none developed detectable IgM antibodies, whereas 33 of 35 (94%) with no detectable preexisting IgG antibodies developed an IgM response. Of a sample of 57 measles cases with a prior history of vaccination, 55 (96%) had detectable IgM antibodies. Of these, 30 (55%) were classified as having a primary antibody response and 25 (45%) a secondary antibody response based on differences in their ratios of IgM to IgG antibodies. Differences in the severity of clinical symptoms between these 2 groups were consistent with this classification scheme. These findings suggest that 1) an IgM response follows primary measles vaccination in the immunologically naive, 2) an IgM response is absent on revaccination of those previously immunized, and 3) an IgM response may follow clinical measles virus infection independent of prior immunization status.

Adolescent↗
PubMed1993

Subacute measles encephalitis in the young immunocompromised host: report of two cases diagnosed by polymerase chain reaction and treated with ribavirin and review of the literature.

Two young patients with subacute measles encephalitis are described: a 20-year-old male hemophiliac infected with human immunodeficiency virus (HIV) and a 4-year-old girl with acute leukemia. Both patients were afebrile and had persistent focal seizures and slurred speech beginning 2 and 7 months, respectively, after the onset of uncomplicated acute measles. The diagnosis of subacute measles encephalitis was established by demonstration of paramyxovirus nucleocapsid on electron microscopy of brain tissue in one case and by detection of measles virus genome with the polymerase chain reaction in both. Treatment of the HIV-infected man with intravenous ribavirin was begun when the patient lost consciousness after several weeks of seizures; he died. The girl with leukemia was treated early after the onset of symptoms and recovered after a 15-week course. Review of 31 previously published cases revealed a typical clinical presentation. Cerebrospinal fluid (CSF) analysis, electroencephalography, measurement of measles antibody in serum and CSF, and computed tomography of the brain were not helpful in the diagnosis of subacute measles encephalitis. In contrast, histologic examination of brain tissue proved useful in establishing the diagnosis. On the basis of our experience and our literature review, we conclude that histologic and polymerase chain reaction studies of brain tissue are required for the early diagnosis of subacute measles encephalitis and that therapy with intravenous ribavirin is effective when administered early.

Adult↗