In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: The use of a system for continuous control of endotracheal tube cuff pressure reduced the incidence of ventilator-associated pneumonia (VAP) in one randomized controlled trial (RCT) with 112 patients but not in another RCT with 142 patients. In several guidelines on the prevention of VAP, the use of a system for continuous or intermittent control of endotracheal cuff pressure is not reviewed. The objective of this study was to compare the incidence of VAP in a large sample of patients (n=284) treated with either continuous or intermittent control of endotracheal tube cuff pressure.', 'We performed a prospective observational study of patients undergoing mechanical ventilation during more than 48 hours in an intensive care unit (ICU) using either continuous or intermittent endotracheal tube cuff pressure control. Multivariate logistic regression analysis (MLRA) and Cox proportional hazard regression analysis were used to predict VAP. The magnitude of the effect was expressed as odds ratio (OR) or hazard ratio (HR), respectively, and 95% confidence interval (CI).', 'We found a lower incidence of VAP with the continuous (n=150) than with the intermittent (n=134) pressure control system (22.0% versus 11.2%; p=0.02). MLRA showed that the continuous pressure control system (OR=0.45; 95% CI=0.22-0.89; p=0.02) and the use of an endotracheal tube incorporating a lumen for subglottic secretion drainage (SSD) (OR=0.39; 95% CI=0.19-0.84; p=0.02) were protective factors against VAP. Cox regression analysis showed that the continuous pressure control system (HR=0.45; 95% CI=0.24-0.84; p=0.01) and the use of an endotracheal tube incorporating a lumen for SSD (HR=0.29; 95% CI=0.15-0.56; p<0.001) were protective factors against VAP. However, the interaction between type of endotracheal cuff pressure control system (continuous or intermittent) and endotracheal tube (with or without SSD) was not statistically significant in MLRA (OR=0.41; 95% CI=0.07-2.37; p=0.32) or in Cox analysis (HR=0.35; 95% CI=0.06-1.84; p=0.21).\Question: Does continuous endotracheal tube cuff pressure control system protect against ventilator-associated pneumonia?
[EX A]: The use of a continuous endotracheal cuff pressure control system and/or an endotracheal tube with a lumen for SSD could help to prevent VAP in patients requiring more than 48 hours of mechanical ventilation.

[EX Q]: Context: Thus far, live attenuated SIV has been the most successful method for vaccinating macaques against pathogenic SIV challenge; however, it is not clear what mechanisms are responsible for this protection. Adoptive transfer studies in mice have been integral to understanding live attenuated vaccine protection in models like Friend virus. Previous adoptive transfers in primates have failed as transferred cells are typically cleared within hours after transfer.', 'Here we describe adoptive transfer studies in Mauritian origin cynomolgus macaques (MCM), a non-human primate model with limited MHC diversity. Cells transferred between unrelated MHC-matched macaques persist for at least fourteen days but are rejected within 36 hours in MHC-mismatched macaques. Cells trafficked from the blood to peripheral lymphoid tissues within 12 hours of transfer.\Question: Do allogeneic lymphocytes persist and traffic in feral MHC-matched mauritian cynomolgus macaques?
[EX A]: MHC-matched MCM provide the first viable primate model for adoptive transfer studies. Because macaques infected with SIV are the best model for HIV/AIDS pathogenesis, we can now directly study the correlates of protective immune responses to AIDS viruses. For example, plasma viral loads following pathogenic SIV challenge are reduced by several orders of magnitude in macaques previously immunized with attenuated SIV. Adoptive transfer of lymphocyte subpopulations from vaccinated donors into SIV-naive animals may define the immune mechanisms responsible for protection and guide future vaccine development.

[EX Q]: Context: A cross-sectional community-based study was conducted among brothel-based sex workers of West Bengal, eastern India, to study the prevalence of HIV and associated risk factors.', 'Unlinked anonymous HIV testing was performed on 2076 sex workers. Of these, 558 were interviewed using a pre-tested questionnaire to study their risk factors.', 'Overall HIV sero-prevalence was 5.9%. All infections were HIV-1, except that four sex workers from Kolkata were infected with HIV-2. Surprisingly, HIV infection was much higher (12.5%) in younger sex workers (age < or =20 years) compared with older age groups (5.4%) (P=0.002; odds ratio 2.40, 95% CI: 1.29-4.38).\Question: Is young age a risk factor for HIV among female sex workers -- an experience from India?
[EX A]:
This could be associated with larger areas of cervical ectopy of younger sex workers who are subjected to repeated trauma during sexual intercourse, facilitating higher HIV transmission. Behavioral factors may increase a young sex worker's risk of acquiring HIV infection, including professional immaturity with clients, which might lead to more unprotected sex. HIV status was associated with other sexually transmitted infection in the previous year but was not associated with literacy status, daily income, duration of sex work, number of clients entertained per day, entertaining clients outside a brothel (in a hotel), and reported condom use.