Seroresponse to the second measles vaccine dose at school entry in Qassim province, Saudi Arabia

In 2001, the measles immunization schedule in Saudi Arabia was changed to 2 measles, mumps and rubella vaccine doses at 12 months and at 6 years. In this follow-up study we evaluated the seroresponse to the second measles dose before school entry. We recruited 138 children randomly from primary health care centres in Qassinn; 124 children completed the study. Blood samples were collected before and 1 month after giving the second measles dose, before the age of 6 years. There was a statistically significant increase in the geometric mean titre of measles antibody, from 2205 m lU/mL before vaccination to 4723 mlU/mL after [P = 0.0001]. The proportion of children with positive ELISA results increased fro++ 94.2% before vaccination to 99.2% after [P = 0.02], while the proportion with protective level [

Plasmodium falciparum infection during pregnancy in an unstable transmission area in eastern Sudan

A 1-year prospective community-based study of malaria during pregnancy was conducted in an area of seasonal and unstable malaria transmission in eastern Sudan. At a village antenatal clinic, 89 non-pregnant controls and 86 pregnant women were enrolled and followed every 2 weeks until 6 weeks after delivery. The incidence of Plasmodium falciparum infection was significantly higher among pregnant than control women [17.4% versus 5.6%] with no difference between primigravidae and multigravidae [22.2% versus 15.2%].There was no significant difference in the mean haemoglobin concentration between infected and uninfected mothers [9.1 +/- 1.3 versus 9.5 +/- 0.6 g/dL] but the mean birth weight of their babies was significantly lower [2.72 +/- 0.26 versus 2.95 +/- 0.05 kg] despite prompt case management of infected women

Analysis of the T-cell receptor V beta usage in monozygotic and dizygotic twins living in a Plasmodium falciparum endemic area in west Africa.

To investigate the influence of genetic and/or environmental factors in the development and shaping of the human peripheral T cell repertoire the authors studied the T-cell receptor (TCR) V beta usage in 10 adult monozygous (Mz) and nine dizygous (Dz) twin pairs living in a Plasmodium falciparum endemic area in West Africa. The TCR repertoire was determined using a small panel of anti-V beta specific monoclonal antibodies (MoAbs) using conventional immunofluorescence assays. The results revealed that the V beta repertoire was similar to that recently described for a Caucasian population using a similar panel of antibodies. The frequencies of particular V beta genes tested were influenced neither by anti-malarial antibody titres nor by parasite densities, indicating that the P. falciparum parasite is not a dominating factor in determining the peripheral T cell repertoire. All donors were human leucocyte antigen (HLA) class I and II typed; no association was found between the expression of any V beta genes and MHC haplotype. The V beta usage was more concordant within the Mz than within the Dz pairs. For a group comprising four HLA class II identical individuals, the average within-pair difference was significantly greater than for the whole Mz group, but similar to that seen for the total Dz group. Thus, the data suggest that genetic, rather than environmental, factors have a profound effect on the shaping of the human circulating T cell repertoire and that the major genetic factors are encoded by non-HLA class II genes.