Kinetics of pneumococcal antibodies among HIV-exposed, uninfected infants in Botswana

Infectivity and Immunogenicity of Live-Attenuated Respiratory Syncytial Virus Vaccines in Human Immunodeficiency Virus-Exposed Uninfected Children

Background

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory illness among young children. Human immunodeficiency virus (HIV)-exposed, uninfected (HEU) children experience a higher burden of RSV disease and have immune abnormalities that may influence their responses to live-attenuated RSV vaccines.

Methods

In a pooled analysis of clinical trials of 7 live-attenuated, intranasal RSV vaccines conducted by the IMPAACT Network among children 6 to <25 months of age with serum RSV-neutralizing titers of <1:40, the infectivity and immunogenicity of these vaccines were compared among HEU and HIV-unexposed, uninfected (HUU) children. Nasal washes were collected during the first 28 days after vaccination. Serum RSV-neutralizing and anti-RSV F glycoprotein immunoglobulin G (IgG) antibodies were measured prior to and 56 days after vaccination, and before and after the following winter season.

Results

Of 156 children, 90 (58%) were HUU and 66 (42%) were HEU. Seventy-six (84%) HUU and 63 (95%) HEU participants were infected with vaccine (shed vaccine virus and/or had a ≥4-fold rise in serum RSV antibodies at 56 days after vaccination). HUU children had higher serum RSV-neutralizing and anti-RSV F IgG titers prior to vaccination. Compared to HEU children, lower percentages of HUU children had ≥4-fold rises in RSV-neutralizing (67% vs 88%) and anti-RSV F IgG (70% vs 89%) titers at 56 days after vaccination.

Conclusions

Live-attenuated RSV vaccines are highly immunogenic in HEU children. Given their increased burden of RSV disease and higher early childhood mortality in some settings, HEU children should be prioritized for vaccination against RSV as these vaccines become available.

Chemical components with antibacterial properties found in sanchen powder from traditional Tibetan medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Sanchen powder is a traditional Tibetan medicine comprising Bambusae Concretio Silicea, Carthami Flos, and Bovis Calculus Artifactus. Bambusae Concretio Silicea is the dried mass of secreted fluid in the stalks of Gramineae plants such as Bambusa textilis McClure or Schizostachyum chinense Rendle. Carthami Flos is the dried flower of Carthamus tinctorius L. in the Compositae plant. Bovis Calculus Artifactus is made from ox bile powder, cholic acid, hyodeoxycholic acid, taurine, bilirubin, cholesterol, and trace elements. Research has evidenced the antibacterial efficacy of Sanchen powder, albeit its active constituents for this effect are yet to be established.

AIM OF THE STUDY

To investigate effective compounds, potential targets, and molecular mechanism of Sanchen powder for its antibacterial properties by using network pharmacology combined with in vitro validation, with the aims of observing the action of effective compounds in Sanchen powder and exploring new therapeutic strategies for antibacterial.

MATERIALS AND METHODS

In this study, UPLC-Q-TOF-MS was utilized to identify the chemical composition in Sanchen powder and its blood-borne chemical ingredients post-oral intake. A network pharmacology analysis was used to establish the chemical compound in the blood following oral administration-target-disease network. The study aimed to identify antibacterial active ingredients, which were then subjected to molecular docking and pharmacodynamic experiments to verify their efficacy.

RESULTS

The findings demonstrate that following oral administration, the blood contains seven key components of Sanchen powder, including bilirubin, glycochenodeoxycholic acid, glycocholic acid, taurocholic acid, phenylalanine, safflomin A, and tryptophan. Additionally, the network pharmacology and molecular docking study results indicate the potential antibacterial effects of bilirubin, glycocholic acid, and glycochenodeoxycholic acid. In vitro antibacterial experiments revealed that bilirubin, glycocholic acid, and glycochenodeoxycholic acid could restrict the growth of the Staphylococcus aureus cell membrane at a certain concentration. Moreover, they exhibited antibacterial effects on Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Escherichia coli.

CONCLUSIONS

Bilirubin, glycocholic acid, and glycochenodeoxycholic acid could be effective therapeutic ingredients for the antibacterial effects of Sanchen powder. These results offer a foundation for further clinical application and research on the antibacterial effect of Sanchen powder, a Traditional Tibetan Medicine.

Clinical and immunological outcomes of HIV-exposed uninfected and HIV-unexposed uninfected children in the first 24 months of life in Western Kenya

BACKGROUND

Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life.

METHODS

Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers living with HIV received combination antiretroviral therapy. Children who were HEU received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined.

RESULTS

Children who were HEU and children who were HUU had similar growth curves. Children who were HEU had lower rates of malaria (rate ratio 0.54, 95% CI 0.38, 0.77) and respiratory illness (rate ratio 0.80, 95% CI 0.68, 0.93). Trajectories of plasma cytokines and vaccine-specific antibodies were similar in children who were HEU and HUU. There were subtle differences in antimalarial antibody dynamics, in which children who were HEU had overall lower antibody levels against five of the 14 malaria antigens tested.

CONCLUSIONS

Children who were HEU and born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to children who were HUU. Children who were HEU had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis.

Clinical and Immunological Outcomes of HIV-Exposed Uninfected and HIV-Unexposed Uninfected Children in the First 24 Months of Life in Western Kenya

Background

Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life.

Methods

Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers with HIV received combination antiretroviral therapy. HEU children received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined.

Results

HEU and HUU children had similar growth curves. HEU children had lower rates of malaria and respiratory illness. Trajectories of plasma cytokines and vaccine-specific antibodies were similar in HEU and HUU children. There were subtle differences in antimalarial antibody dynamics, in which HEU children had overall lower antibody levels against five of the 14 malaria antigens tested.

Conclusions

HEU children born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to HUU children. HEU children had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis.