Inactivated influenza vaccine reduced proven influenza illness by 63% in infants up to 6 months of age and averted approximately a third of all febrile respiratory illnesses in mothers and young infants. Maternal influenza immunization is a strategy with substantial benefits for both mothers and infants. (ClinicalTrials.gov number, NCT00142389.)

Pneumococci are a leading cause of severe bacterial disease in infants and children world wide. A possible means of protecting infants in the first few months of life is immunisation of the mother during pregnancy. We prospectively assessed pneumococcal immunisation of pregnant women to determine the amount of pneumococcal antibody transmitted to the infants in serum and milk and the half-life of the passively acquired antibody. Healthy pregnant women in Dhaka, Bangladesh, were randomised to receive pneumococcal or meningococcal vaccine with routine prenatal tetanus immunisation at 30-34 weeks of gestation. Serum and breast milk specimens from the mothers and sera from infants were collected up to 22 weeks of age and assayed for specific serum IgG, IgG1, and IgG2 and for milk IgA antibodies to pneumococcal serotypes 6B and 19F. 55 mothers and 56 infants were followed from birth to five months. Women who received pneumococcal vaccine had geometric mean antibody increases of 2.6 and 3.4 to types 6B and 19F, respectively. The mean infant/maternal antibody ratios were 0.56 and 0.59 (range 0.11-1.46) for these serotypes. Infant cord antibody titres correlated with maternal titres. Infant/maternal IgG ratios correlated with the interval between immunisation and birth and were higher for specific IgG1 than for IgG2. Infants of pneumococcal vaccine recipients had geometric mean antibody concentrations of 6.8 and 7.5 micrograms/mL to serotypes 6B and 19F in cord blood; in cord blood and in all subsequent serum specimens the concentrations were 2-3 fold higher than in control infants. The median half-life of passive antibody was about 35 days; at five months of age 63-71% of infants of pneumococcal vaccine recipients had antibody concentrations greater than 0.15 micrograms/mL. Breast milk IgA antibodies for pneumococcal serotype 19F, but not for type 6B, were significantly higher in vaccine recipients up to five months after delivery. If maternal pneumococcal polysaccharide antibodies do not interfere with active immunisation of the infant with new glycoprotein conjugate pneumococcal vaccines, passive-active immunisation of infants can be a feasible strategy for developing regions.

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With a systematically sampled population of children aged under 5 attending this centre for diarrhoeal disease research during 1983-5 a retrospective analysis of persistent diarrhoea (defined as >14 days' duration) was performed to identify the possible risk factors for this syndrome. Of the 4155 children included in the analysis, 410 (10%) gave a history of persistent diarrhoea. A comparison with children with acute diarrhoea matched for age showed that 11 factors were correlated with persistent diarrhoea, and strongly associated factors were stools with blood or mucus, or both, lower respiratory tract infection, malnutrition, vitamin A deficiency, and antibiotic use before presentation. The peak age was 2 years, and there was no sex difference. Deaths occurred more often in the group with persistent diarrhoea. Although Shigella spp, Campylobacter jejuni, and Giardia lamblia were frequently identified, their rates of isolation were not significantly higher among patients with persistent diarrhoea. No seasonal variation was observed in the rates of persistent diarrhoea. Although the introduction offamily food to the diet was associated with higher rates, this factor was difficult to separate from the age dependent risks.

Shigella dysenteriae type 1 (Shiga bacillus) has made a dramatic comeback in Bangladesh after 10 years when Shigella flexneri was the dominant serogroup. Whereas S. flexneri showed little increase in resistance to the commonly used antimicrobial agents--namely, trimethoprim-sulfamethoxazole (TMP-SMX) and ampicillin-over the years, S. dysenteriae type 1 underwent rapid changes with regard to sensitivity pattern during the last two years. The first TMP-SMX-resistant strain of S. dysenteriae type 1 was detected in September 1982; however, by mid-1984 most strains were resistant while retaining sensitivity to ampicillin. During this period, the ratio of S. flexneri to S. dysenteriae type 1 narrowed from 0.15 to 1. Such propagation of high resistance to TMP-SMX might have been due to widespread use of the drug imported into the country in large quantities. Resistance to ampicillin is increasing rapidly, particularly in S. dysenteriae type 1.