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Biomedical subjects

S A Plotkin

Publications and source records attributed to S A Plotkin.

At least 55 records · Page 3Linked to original sources
PubMed1997

Sequential and combined use of inactivated and oral poliovirus vaccines: Dolj District, Romania, 1992-1994.

To determine the feasibility of a vaccination strategy that would reduce the risk of vaccine-associated paralysis while retaining a barrier against the spread of wild poliovirus, a 2-year project was undertaken using enhanced-potency inactivated poliovirus vaccine (IPV) administered at 2 and 3 months of age followed by doses of both IPV and oral poliovirus vaccine (OPV) administered at 4 and 9 months of age. Vaccination coverage by 12 months of age with three or more doses of IPV and two doses of OPV among 16,566 infants eligible for vaccination was > 95% and > 80%, respectively. Among 51 children from whom blood samples were obtained 45 days after their third dose of IPV and first dose of OPV, 100% had serum neutralizing antibodies (reciprocal titer > or = 10) to all three poliovirus types. No cases of paralytic poliomyelitis due to either wild or vaccine-related strains were reported. The project demonstrated the feasibility, safety, and high immunogenicity of sequential use of IPV followed by OPV in Romania.

Antibodies, Viral↗
PubMed1997

Bali Low.

Explore the source record for details and available documents.

Chloroquine↗
PubMed1997

The effectiveness of whole-cell pertussis vaccines.

The acellular pertussis vaccine efficacy trials revealed significant facts concerning the whole cell vaccines used as controls. At least three whole-cell vaccines were shown to have considerable efficacy, and in fact superior efficacy to the acellular vaccines to which they were compared. One whole-cell vaccine, previously shown to be poorly immunogenic after three doses, was correspondingly low in protective efficacy. Although acellular vaccines may be preferred in some countries because of their lower reactogenicity, we are faced with the fact that a well-prepared whole-cell vaccine still provides the best protection against pertussis.

Antibodies, Bacterial↗
PubMed1996

The N-terminal 303 amino acids of the human cytomegalovirus envelope glycoprotein B (UL55) and the exon 4 region of the major immediate early protein 1 (UL123) induce a cytotoxic T-cell response.

We reported earlier that an adenovirus (Ad) recombinant expressing the full-length human cytomegalovirus (HCMV) glycoprotein B (gB) gene induces gB-specific cytotoxic T lymphocyte (CTL) responses in CBA (H-2k) mice (Berencsi et al., J. Gen. Virol. 74, 257-2512, 1993). Here we show that mice immunized with Ad recombinant viruses expressing truncated forms of the gB gene containing the first 700 (Ad-700), 465 (Ad-465) or 303 (Ad-303) amino acids of gB or an Ad construct containing exon 4 (E4) of the HCMV immediate early 1 (IEI) gene (Ad-IEI (E4)) demonstrate HCMV-specific CTL responses. These data suggest the importance of the first 303 amino acids of the gB polypeptide and the IEI E4 product in designing a vaccine to induce anti-HCMV CTL responses.

Animals↗
PubMed1996

Mucosal antibodies to human cytomegalovirus glycoprotein B occur following both natural infection and immunization with human cytomegalovirus vaccines.

Because antibodies against human cytomegalovirus (HCMV) glycoprotein B (gB) neutralize, levels of IgG, secretory IgA (sIgA), and mucosal IgA1 antibodies to HCMV were measured in saliva and nasal washes. Ten seronegative adults lacked these antibodies, but of 10 naturally seropositive adults, 10 had IgG to gB, 5 had sIgA, and 0 had mucosal IgA. Among 12 recipients of a live HCMV vaccine, 8 had IgG to gB, 4 had sIgA, and 2 had mucosal IgA in samples collected 10-20 months after immunization; of 10 recipients of a gB vaccine, 8 had IgG to gB, 7 had sIgA, and 7 had mucosal IgA in samples collected just before or 1 month after a booster. IgG to gB and neutralizing titers in serum correlated with IgG to gB in mucosal samples. IgG to gB was in the saliva of 25 of 26 subjects with serum neutralizing titers > 1:64. Serum neutralizing titers > 1:64, whether induced by vaccine or wild type virus, are associated with mucosal IgG to HCMV.

Adolescent↗
PubMed1996

The development of multivalent bovine rotavirus (strain WC3) reassortant vaccine for infants.

Laboratory and clinical studies have been directed toward development of a vaccine against rotavirus gastroenteritis in infants. First, bovine rotavirus strain WC3, which did not induce neutralizing antibodies to predominant human rotavirus (HRV) serotypes, was determined to be safe and immunogenic; however, it was not protective in all efficacy trials. HRVs adapted to cell culture retained some virulence for infants, but when further attenuated by cold adaptation, they were poorly immunogenic. Reassortant rotaviruses were designed to express HRV surface proteins VP7 (G) or VP4 (P) while retaining a bovine WC3 genome background. Reassortants containing either HRV surface protein and as few as four bovine rotavirus genes were safe in infants. A monovalent WC3 reassortant of serotype G1 specificity was 64%-100% protective in placebo-controlled trials. A quadrivalent WC3 reassortant vaccine with components of HRV G1, G2, G3, and P[8] specificity induced 67% protection against all rotavirus disease in a multicenter efficacy trial.

Animals↗
PubMed1995

A new typhoid vaccine composed of the Vi capsular polysaccharide.

Typhoid is still prevalent in many parts of the world. We reviewed all published and unpublished studies of a newly licensed vaccine composed of the Vi capsular polysaccharide of Salmonella typhi, the causative agent of the disease, which had been licensed previously outside the United States. These included observational studies and double-blind randomized studies done in the United States, Europe, and the developing world in which children and adults unexposed to typhoid or those living in endemic areas were enrolled. A single dose of 25 micrograms of the purified polysaccharide was given by intramuscular injection. The vaccine was well tolerated, inducing only minor reactions in fewer than 10% of subjects. An antibody response occurred in about 90% of subjects and lasted about 3 years. Seroconversion was shown in children as young as 2 years. Protective efficacy was evaluated in two studies conducted in areas in which typhoid is endemic; the efficacy was 55% and 75%, respectively, in adults and in children older than 5 years. The Vi vaccine compares favorably with other typhoid vaccines in regard to safety, patient compliance, immunogenicity, and efficacy. Vi polysaccharide is a well-standardized antigen that is effective in a single parenteral dose, is safer than whole-cell vaccine, and may be used in children 2 years of age or older.

Adult↗
PubMed1995

Preclinical evaluation of an ALVAC (canarypox)--human cytomegalovirus glycoprotein B vaccine candidate.

Successful vaccination against the human cytomegalovirus (HCMV) requires induction of both neutralizing antibody and cytotoxic T lymphocyte (CTL) responses. The HCMV glycoprotein B (gB, UL55) would be one of the most important immunogens to induce neutralizing antibodies. We tested the immunogenicity of an ALVAC (canarypox)-HCMV-gB (ALVAC-gB) recombinant in mice and guinea pigs in order to provide preclinical data for a phase I clinical trial of a HCMV vaccine candidate. ALVAC is an attenuated vaccine strain of canarypox virus which replicates productively in avian species but abortively in mammalian cells. The ALVAC-gB recombinant inoculated subcutaneously in mice and intramuscularly in guinea pigs induced HCMV-specific neutralizing antibodies and gB-specific CTL responses. Ultraviolet irradiation of the ALVAC-gB recombinant before immunization diminished CTL responses, indicating that intracellular expression and processing of gB-protein were necessary for CTL induction. Prior immunity to vaccinia virus did not decrease immunogenicity of the ALVAC-gB recombinant in mice. Thus, despite its host range restriction, ALVAC-gB is potentially capable of inducing both humoral and cell-mediated immune responses to HCMV in both vaccinia-immune and non-immune individuals.

Animals↗
PubMed1995

Immunity induced by primary human cytomegalovirus infection protects against secondary infection among women of childbearing age.

To determine if immunity to human cytomegalovirus (HCMV) protects women from acquiring HCMV from their children, a blinded, randomized protocol was used to monitor seronegative women who received placebo or Towne vaccine (approximately 500 pfu) and seropositive women. Each group was similar for mean maternal (33 years) and child age (18 months) and duration of viral shedding by the child (15 months). Among 19 placebo recipients, 9 developed primary infection; 8 of 19 vaccines but only 3 of 42 naturally seropositive subjects had evidence of acquiring HCMV from their child. Wild type infection and Towne vaccine induced similar mean lymphoproliferative responses to HCMV antigens, but one dose of Towne vaccine produced mean neutralizing titers 10- to 20-fold lower than those after wild type infection. Thus, a vaccine that induces immune responses equal to those induced by wild type virus may protect healthy women from acquiring HCMV from their children.

Adult↗