Background Monovalent type 2 oral poliovirus vaccine (mOPV2) stockpile is low. One potential strategy to stretch the existing mOPV2 supply is to administer a reduced dose: one-drop instead of two-drops. Methods We conducted a randomized, controlled, open-label, non-inferiority trial (10% margin) to compared immunogenicity following administration of one versus two-drops of mOPV2. We enrolled 9-22-months old infants from Mocuba district of Mozambique. Poliovirus neutralizing antibodies were measured in sera collected before and one month after mOPV2 administration. Immune response was defined as seroconversion from seronegative (<1:8) at baseline to seropositive (>1:8) after vaccination or boosting titers by >4-fold for those with titers between 1:8 and 1:362 at baseline. The trial was registered at anzctr.org.au (number ACTRN12619000184178p). Results We enrolled 378 children and 262 (69%) completed per-protocol requirements. Immune response of mOPV2 was 53.6% (95% confidence interval [CI]: 44.9%-62.1%) and 60.6% (95% CI: 52.2%-68.4%) in 1-drop and 2-drops recipients, respectively. The non-inferiority margin of the 10% was not reached (difference=7.0%; 95%CI= -5.0-19.0). Conclusion A small loss of immunogenicity of reduced mOPV2 was observed. Although the non-inferiority target was not achieved, the Strategic Advisory Group of Experts on Immunization, recommended the 1-drop strategy as a dose-sparing measure if mOPV2 supplies deteriorate further.

Introduction Vaccine efficacy testing requires engagement of willing volunteers with high disease incidence. We evaluated factors associated with willingness to participate in potential future HIV vaccine trials in Maputo, Mozambique. Methods Adults aged 18–35 years without HIV and who reported at least two sexual partners in the 3 months prior to screening were enrolled into a 24-month observational study. They were asked at screening and exit if they would be willing to participate in a theoretical HIV vaccine study. Bivariate and multivariate logistic regression analyses were done between willingness to participate, demographic, sexual behavior, and motivational factors for screening visit data. Logistic regression with generalized estimating equations (GEE) was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for factors potentially associated with willingness to participate for data from both visits. Results A total of 577 participants without HIV were eligible, including 275 (48%) women. The mean age was 22.2 (SD ± 3.9) years. At screening 529 (92%) expressed willingness to participate and the proportion remained stable at 378 (88%) of the 430 participants retained through the exit visit (p = 0.209). Helping the country (n = 556) and fear of needles (n = 26) were the top motive and barrier for willingness to participate, respectively. Results from the GEE binary logistic regression (screening visit and exit visit) showed that wanting to learn how to avoid risk behaviors (aOR 3.33, 95% CI: 1.61–6.86) and feeling protected against HIV infection (aOR 2.24, 95% CI: 1.07–4.7) were associated with willingness to participate in HIV vaccine studies. Conclusion The majority of our study population in Mozambique expressed willingness to participate in a theoretical HIV vaccine trial. Participation in a HIV vaccine trial was seen as a way to contribute to the fight against HIV but was associated with some unrealistic expectations such as protection against HIV. This reinforces the need for continuous mobilization and awareness of potential participants to HIV vaccine trial.

Background Human immunodeficiency virus type 1 (HIV-1) causes impairment of T and B cell responses, which begins during the acute phase of infection and is not completely restored by antiretroviral treatment. Regulatory T cell (Tregs) can improve overall disease outcome by controlling chronic inflammation but may also suppress beneficial HIV-1 specific immune responses. We aimed to analyze the profile of Tregs and their correlation with the status of T cells activation, the expression of IL-2 and IFNγ and the profile of HIV-1 specific antibodies response in Mozambican people living chronically with HIV-1 (PLWH-C). Results In PLWH-C, the proportion of total Tregs was positively correlated with the proportion of IL-2+CD4 T cells (r = 0.647; p = 0.032) and IL-2+IFNγ+CD8 T cells (r = 0.551; p = 0.014), while the proportions of Helios+Tregs correlated inversely with levels of IL-2+CD8 T cells (r = − 0.541; p = 0.017). Overall, PLWH-C, with (82%) or without virologic suppression (64%), were seronegative for at least HIV-1 p31, gp160 or p24, and the breadth of antibody responses was positively correlated with proportions of CD38+HLA-DR+CD8 T cells (r = 0.620; p = 0.012), viral load (r = 0.452; p = 0.040) and inversely with absolute CD4 T cells count (r = − 0.481; p = 0.027). Analysis of all individuals living HIV-1 showed that the breadth of HIV-1 antibody responses was inversely correlated with the proportion of Helios+Tregs (r = − 0.45; p = 0.02). Conclusion Among Mozambican people living with HIV-1, seronegativity to some HIV-1 proteins is common, particularly in virologically suppressed individuals. Furthermore, lower diversity of HIV-specific antibodies is correlated to lower immune activation, lower viral replication and higher CD4 counts, in PLWH-C. Elevation in the proportion of Helios+Tregs is related to a reduction of CD8 T expressing intracellular IL-2, in PLWH-C, but may contribute to impairment of B cell function.

Background PrEP literacy is influenced by many factors including the types of information available and how it is interpreted. The level of PrEP literacy may influence acceptability and uptake. Methods We conducted 25 in-depth interviews in a HIV vaccine trial preparedness cohort study. We explored what participants knew about PrEP, sources of PrEP knowledge and how much they know about PrEP. We used the framework approach to generate themes for analysis guided by the Social Ecological Model and examined levels of PrEP literacy using the individual and interpersonal constructs of the SEM. Results We found that PrEP awareness is strongly influenced by external factors such as social media and how much participants know about HIV treatment and prevention in the local community. However, while participants highlighted the importance of the internet/social media as a source of information about PrEP they talked of low PrEP literacy in their communities. Participants indicated that their own knowledge came as a result of joining the HIV vaccine trial preparedness study. However, some expressed doubts about the effectiveness of the drug and worried about side effects. Participants commented that at the community level PrEP was associated with being sexually active, because it was used to prevent the sexual transmission of HIV. As a result, some participants commented that one could feel judged by the health workers for asking for PrEP at health facilities in the community. Conclusion The information collected in this study provided an understanding of the different layers of influence around individuals that are important to address to improve PrEP acceptability and uptake. Our findings can inform strategies to address the barriers to PrEP uptake, particularly at structural and community levels. Trial registration https://clinicaltrials.gov/ct2/show/NCT04066881