By RT-qPCR, mRNA of IL-8 showed an immediate down-regulation followed by a slow up-regulation which was statistically significant (P = 0.02) in a regression model against time ( Fig. 1). There was no discernible effect of vaccination on IL-1β ( Fig. 2) or IFNγ ( Fig. 3). TNFα expression was undetectable in a considerable number of samples: in 6 cases there was no detectable expression before or after vaccination; in 5 cases mRNA was detected only before vaccination, and in 5 cases only after vaccination. In the remaining 5 cases, click here there

was a modest down-regulation, but this was not statistically significant in view of the small number of data pairs. HIV-infected participants did not differ from HIV-uninfected this website participants with

respect to changes in cytokine expression following vaccination, and those biopsies in which TNFα expression was not detectable were not more likely to come from HIV-infected participants (data not shown). The safety of live, attenuated vaccines in HIV infected people is of paramount importance if vaccines are to play any role in reducing the burden of common diseases in tropical populations. In this study we found that in 34 HIV seropositive adults given a total of 58 courses of three live, attenuated oral vaccines there was no evidence of serious adverse events: no hospitalisations, no episodes of diarrhoea requiring treatment, no significant febrile illnesses, and no increase in symptoms such as abdominal pain, nausea or loss of appetite. There was no evidence of haematological toxicity. If we accept that oral vaccines do not either cause diarrhoea after 7 days have elapsed beyond the final dose of vaccine, there was no increase in diarrhoea. The interpretation of diarrhoea data in this setting is difficult if we use HIV seronegative adults as the comparison group, as at any given point

in time HIV infected adults have a higher incidence rate of diarrhoeal disease [19]. We believe that this explains the higher diarrhoea incidence after 7 days following vaccination. Our data are compatible with the hypothesis that these vaccines lead to a modest increase in mild, transient episodes of diarrhoea beyond 1 week in HIV infected adults. They are also explicable with there being a consistently increased risk of diarrhoea in HIV throughout the period of observation. We found no evidence that vaccines induce intestinal inflammation. IL-8 is a chemokine expressed by epithelial cells on contact with potentially invasive bacteria. The other, pro-inflammatory, cytokines showed no change in expression over the week following vaccination. While these data do not rule out a pathogenic effect of these vaccines, they offer considerable reassurance that rotavirus vaccine does not induce inflammation.