Vaccine
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Randomized Controlled Trial Clinical Trial
Immunogenicity of high-titre AIK-C or Edmonston-Zagreb vaccines in 3.5-month-old infants, and of medium- or high-titre Edmonston-Zagreb vaccine in 6-month-old infants, in Kinshasa, Zaire.
The effect of measles vaccine potency was evaluated among 485 children aged 6 months, and the effect of vaccine strain was evaluated among 538 children aged 3.5 months, in Kinshasa, Zaire. Children aged 6 months were randomly assigned to receive either high-titre Edmonston-Zagreb (EZ-H), potency 5.7 log10/dose, or medium-titre EZ (EZ-M), potency 4.7 log10/dose, those aged 3.5 months were randomly assigned to receive either AIK-C, potency 5.5 log10/dose, or EZ-H, and were revaccinated with EZ-M vaccine at age 9.5 months. Measles antibodies were measured using the plaque reduction neutralization assay. ⋯ After revaccination at age 9.5 months, 81% of children in the AIK-C group and 73% in the EZ-H group had antibody levels > 200 mIU (p = 0.056). A retrospective survey was conducted in January 1993 to determine the mortality experience of vaccine groups, and information was obtained for 94% of the children. A total of 44 deaths (4%) were identified, with no significant differences between groups when stratified by age at vaccination.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
A trial of the synthetic malaria vaccine SPf66 in Tanzania: rationale and design.
The development of a safe, affordable and effective malaria vaccine to form part of control schemes in malaria endemic countries is a priority for researchers and public health officials. SPf66 is the first malaria vaccine to have shown partial protection against natural challenge in a phase III trial carried out in a hypoendemic area of Colombia. This paper describes the rationale and design of the first field trial of SPf66 outside South America, and the first to be conducted in an area of high perennial transmission.
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The antimetastatic effects of MDP-Lys(L18), a lipophilic derivative of muramyl dipeptide (MDP), against three different types of highly metastatic murine tumour cells, B16-BL6 melanoma, colon 26-M3.1 carcinoma and L5178Y-ML25 T lymphoma, were examined in C57BL/6, Balb/c and CDF1 mice, respectively. The administration of 100 micrograms of MDP-Lys(L18) 2 or 4 days before tumour inoculation led to a significant decrease in lung metastasis of B16-BL6 melanoma or colon 26-M3.1 carcinoma cells. MDP-Lys(L18) was also effective in the inhibition of liver metastasis of L5178Y-ML25 lymphoma cells by administration 2 or 4 days before tumour inoculation. ⋯ Administration of MDP-Lys(L18) 4 days before assay led to induction of tumoricidal activity by peritoneal macrophages and growth inhibition by the sera against B16-BL6 or L929 cells. When MDP-Lys(L18) was subcutaneously administered five times after tumour inoculation to test therapeutic effect in an experimental and spontaneous metastasis model using B16-BL6 melanoma, the consecutive administrations of MDP-Lys(L18) significantly inhibited lung metastasis in tumour-bearing mice. These results suggest that MDP-Lys(L18) is able to enhance host resistance to reduce tumour metastasis and is a potent immunomodulating agent which may be applied prophylactically or therapeutically for the treatment of cancer metastasis.
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'Children represent the most vulnerable segment of every society--and they are our present and future. Good health, especially of children, promotes personal and national development. Scientific progress, matched with improved capacities of all countries to immunize their children, provides an unparalleled opportunity to save additional lives and prevent additional millions of disabilities annually through a Children's Vaccine Initiative.' (The Netherlands Minister for Development Co-operation.)
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Comparative Study
Lethal toxicity and adjuvant activities of synthetic TDM and its related compounds in mice.
Trehalose-6,6'-dimycolate (TDM) and its monosaccharide-type analogues were synthesized, and their lethal and adjuvant activities were examined in mice. All the monosaccharide-type analogues with a glucose or N-acetylglucosamine moiety were devoid of lethal toxicity to mice; in particular, D-GlcNAcM(1-deoxy) and D-GlcNM did not cause any loss of body weight at an early stage after intravenous administration as a 9% oil-in-water emulsion. ⋯ Squalane-treated D-GlcNAcM(1-deoxy) showed significant inhibition of spontaneous lung metastases by B16-BL6 melanoma cells when it was administered twice intratumorally. The non-toxic monosaccharide-type analogue of TDM [D-GlcNAcM(1-deoxy)] was a beneficial adjuvant for the activation of macrophages and the prevention of cancer metastasis.