Ad26.ZEBOV, MVA-BN-Filo Ebola virus disease vaccine regimen plus Ad26.ZEBOV booster at 1 year versus 2 years in health-care and front-line workers in the Democratic Republic of the Congo: secondary and exploratory outcomes of an open-label, randomised, phase 2 trial.

BACKGROUND: Health-care providers and front-line workers are at risk of contracting Ebola virus disease during an Ebola virus outbreak and consequently of becoming drivers of the disease. We aimed to assess the long-term immunogenicity of the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen and the safety of and immune memory response to an Ad26.ZEBOV booster vaccination at 1 year or 2 years after the first dose in this at-risk population. METHODS: This open-label, single-centre, randomised, phase 2 trial was conducted at one study site within a hospital in Boende, Democratic Republic of the Congo. Adult health-care providers and front-line workers, excluding those with a known history of Ebola virus disease, were vaccinated with a two-dose heterologous regimen administered at a 56-day interval via a 0·5 mL intramuscular injection in the deltoid muscle, comprising Ad26.ZEBOV as the first dose and MVA-BN-Filo as the second dose. After the initial vaccination on day 1, participants were randomly assigned (1:1) via randomisation envelopes, opened in a sequential order, to receive an Ad26.ZEBOV booster vaccination at 1 year (group 1) or 2 years (group 2) after the first dose. We present the secondary and exploratory objectives of the trial-results of the primary objective have been published elsewhere. We measured immunogenicity at six timepoints per group as geometric mean concentrations (GMCs) of Ebola virus glycoprotein-specific IgG binding antibodies, using the Filovirus Animal Non-Clinical Group ELISA. We assessed serious adverse events occurring up to 6 months after the last dose and local and systemic solicited and unsolicited adverse events reported for 7 days after the booster vaccination. Antibody responses were analysed per protocol, serious adverse events per full analysis set (FAS), and adverse events for all boosted FAS participants. This trial is registered as completed on ClinicalTrials.gov (NCT04186000). FINDINGS: Between Dec 18, 2019, and Feb 8, 2020, 699 health-care providers and front-line workers were enrolled and 698 were randomly assigned (350 to group 1 and 348 to group 2 [FAS]); 534 (77%) participants were male and 164 (23%) were female. 319 in group 1 and 317 in group 2 received the booster. 29 (8%) in group 1 and 26 (7%) in group 2 did not complete the study, mostly due to loss to follow-up or moving out of the study area. In both groups, injection-site pain or tenderness (87 [27%] of 319 group 1 participants vs 90 [28%] of 317 group 2 participants) and headache (91 [29%] vs 93 [29%]) were the most common solicited adverse events related to the investigational product. One participant (in group 2) had a related serious adverse event after booster vaccination (fever of ≥40·0°C). Before booster vaccination, Ebola virus glycoprotein-specific IgG binding antibody GMCs were 279·9 ELISA units (EU) per mL (95% CI 250·6-312·7) in 314 group 1 participants (1 year after first dose) and 274·6 EU/mL (242·1-311·5) in 310 group 2 participants (2 years after first dose). These values were 5·2 times higher in group 1 and 4·9 times higher in group 2 than before vaccination on day 1. 7 days after booster vaccination, these values increased to 10 781·6 EU/mL (9354·4-12 426·4) for group 1 and 10 746·9 EU/mL (9208·7-12 542·0) for group 2, which were approximately 39 times higher than before booster vaccination in both groups. 1 year after booster vaccination in 299 group 1 participants, a GMC that was 7·6-times higher than before booster vaccination was still observed (2133·1 EU/mL [1827·7-2489·7]). INTERPRETATION: Overall, the vaccine regimen and booster dose were well tolerated. A similar and robust humoral immune response was observed for participants boosted 1 year and 2 years after the first dose, supporting the use of the regimen and flexibility of booster dose administration for prophylactic vaccination in at-risk populations. FUNDING: Innovative Medicines Initiative 2 Joint Undertaking and Coalition for Epidemic Preparedness Innovations.

Vaccine value profile for Klebsiella pneumoniae.

Klebsiella pneumoniae causes community- and healthcare-associated infections in children and adults. Globally in 2019, an estimated 1.27 million (95% Uncertainty Interval [UI]: 0.91-1.71) and 4.95 million (95% UI: 3.62-6.57) deaths were attributed to and associated with bacterial antimicrobial resistance (AMR), respectively. K. pneumoniae was the second leading pathogen in deaths attributed to AMR resistant bacteria. Furthermore, the rise of antimicrobial resistance in both community- and hospital-acquired infections is a concern for neonates and infants who are at high risk for invasive bacterial disease. There is a limited antibiotic pipeline for new antibiotics to treat multidrug resistant infections, and vaccines targeted against K. pneumoniae are considered to be of priority by the World Health Organization. Vaccination of pregnant women against K. pneumoniae could reduce the risk of invasive K.pneumoniae disease in their young offspring. In addition, vulnerable children, adolescents and adult populations at risk of K. pneumoniae disease with underlying diseases such as immunosuppression from underlying hematologic malignancy, chemotherapy, patients undergoing abdominal and/or urinary surgical procedures, or prolonged intensive care management are also potential target groups for a K. pneumoniae vaccine. A 'Vaccine Value Profile' (VVP) for K.pneumoniae, which contemplates vaccination of pregnant women to protect their babies from birth through to at least three months of age and other high-risk populations, provides a high-level, holistic assessment of the available information to inform the potential public health, economic and societal value of a pipeline of K. pneumoniae vaccines and other preventatives and therapeutics. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public-private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the WHO. All contributors have extensive expertise on various elements of the K.pneumoniae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Safety and Immunogenicity of the Heterologous 2-Dose Ad26.ZEBOV, MVA-BN-Filo Vaccine Regimen in Health Care Providers and Frontliners of the Democratic Republic of the Congo.

BACKGROUND: In response to recent Ebola epidemics, vaccine development against the Zaire ebolavirus (EBOV) has been fast-tracked in the past decade. Health care providers and frontliners working in Ebola-endemic areas are at high risk of contracting and spreading the virus. METHODS: This study assessed the safety and immunogenicity of the 2-dose heterologous Ad26.ZEBOV, MVA-BN-Filo vaccine regimen (administered at a 56-day interval) among 699 health care providers and frontliners taking part in a phase 2, monocentric, randomized vaccine trial in Boende, the Democratic Republic of Congo. The first participant was enrolled and vaccinated on 18 December 2019. Serious adverse events were collected up to 6 months after the last received dose. The EBOV glycoprotein FANG ELISA (Filovirus Animal Nonclinical Group enzyme-linked immunosorbent assay) was used to measure the immunoglobulin G-binding antibody response to the EBOV glycoprotein. RESULTS: The vaccine regimen was well tolerated with no vaccine-related serious adverse events reported. Twenty-one days after the second dose, an EBOV glycoprotein-specific binding antibody response was observed in 95.2% of participants. CONCLUSIONS: The 2-dose vaccine regimen was well tolerated and led to a high antibody response among fully vaccinated health care providers and frontliners in Boende.

Safety and immunogenicity of an Ad26.ZEBOV booster vaccine in Human Immunodeficiency Virus positive (HIV+) adults previously vaccinated with the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen against Ebola: A single-arm, open-label Phase II clinical trial in Kenya and Uganda.

BACKGROUND: People living with HIV constitute an important part of the population in regions at risk of Ebola virus disease outbreaks. The two-dose Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen induces strong immune responses in HIV-positive (HIV+) adults but the durability of this response is unknown. It is also unclear whether this regimen can establish immune memory to enable an anamnestic response upon re-exposure to antigen. METHODS: This paper describes an open-label, phase 2 trial, conducted in Kenya and Uganda, of Ad26.ZEBOV booster vaccination in HIV+ participants who had previously received the Ad26.ZEBOV, MVA-BN-Filo primary regimen. HIV+ adults with well-controlled infection and on highly active antiretroviral therapy were enrolled, vaccinated with booster, and followed for 28 days. The primary objectives were to assess Ad26.ZEBOV booster safety and antibody responses against the Ebola virus glycoprotein using the Filovirus Animal Non-Clinical Group ELISA. RESULTS: The Ad26.ZEBOV booster was well-tolerated in HIV+ adults with mostly mild to moderate symptoms. No major safety concerns or serious adverse events were reported. Four and a half years after the primary regimen, 24/26 (92 %) participants were still classified as responders, with a pre-booster antibody geometric mean concentration (GMC) of 726 ELISA units (EU)/mL (95 %CI 447-1179). Seven days after the booster, the GMC increased 54-fold to 38,965 EU/mL (95 %CI 23532-64522). Twenty-one days after the booster, the GMC increased 176-fold to 127,959 EU/mL (95 %CI 93872-174422). The responder rate at both post-booster time points was 100 %. CONCLUSIONS: The Ad26.ZEBOV booster is safe and highly immunogenic in HIV+ adults with well-controlled infection. The Ad26.ZEBOV, MVA-BN-Filo regimen can generate long-term immune memory persisting for at least 4·5 years, resulting in a robust anamnestic response. TRIAL REGISTRATION: Pan African Clinical Trial Registry (PACTR202102747294430). CLINICALTRIALS: gov (NCT05064956).

Persistence of immunological memory as a potential correlate of long-term, vaccine-induced protection against Ebola virus disease in humans.

Introduction: In the absence of clinical efficacy data, vaccine protective effect can be extrapolated from animals to humans, using an immunological biomarker in humans that correlates with protection in animals, in a statistical approach called immunobridging. Such an immunobridging approach was previously used to infer the likely protective effect of the heterologous two-dose Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen. However, this immunobridging model does not provide information on how the persistence of the vaccine-induced immune response relates to durability of protection in humans. Methods and results: In both humans and non-human primates, vaccine-induced circulating antibody levels appear to be very stable after an initial phase of contraction and are maintained for at least 3.8 years in humans (and at least 1.3 years in non-human primates). Immunological memory was also maintained over this period, as shown by the kinetics and magnitude of the anamnestic response following re-exposure to the Ebola virus glycoprotein antigen via booster vaccination with Ad26.ZEBOV in humans. In non-human primates, immunological memory was also formed as shown by an anamnestic response after high-dose, intramuscular injection with Ebola virus, but was not sufficient for protection against Ebola virus disease at later timepoints due to a decline in circulating antibodies and the fast kinetics of disease in the non-human primates model. Booster vaccination within three days of subsequent Ebola virus challenge in non-human primates resulted in protection from Ebola virus disease, i.e. before the anamnestic response was fully developed. Discussion: Humans infected with Ebola virus may benefit from the anamnestic response to prevent disease progression, as the incubation time is longer and progression of Ebola virus disease is slower as compared to non-human primates. Therefore, the persistence of vaccine-induced immune memory could be considered as a potential correlate of long-term protection against Ebola virus disease in humans, without the need for a booster.

Immune response of a two-dose heterologous Ebola vaccine regimen: summary of three African clinical trials using a single validated Filovirus Animal Nonclinical Group enzyme-linked immunosorbent assay in a single accredited laboratory.

BACKGROUND: This analysis evaluated the immune response to the two-dose, heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola virus vaccine regimen, administered 56-days apart, from multiple African sites based on results from one analytic laboratory. METHODS: Immunogenicity across three trials (EBL2002, EBL2004/PREVAC, EBL3001) conducted in East and West Africa is summarised. Vaccine-induced Ebola glycoprotein-binding antibody concentrations were analysed by Q2 Solutions laboratory at baseline, 21 days (EBL2002 and EBL3001) or 28 days (EBL2004) post-dose 2 (regimen completion), and 12 months post-dose 1 using the validated Filovirus Animal Nonclinical Group Ebola glycoprotein enzyme-linked immunosorbent assay (ELISA). Responders were defined as those with a >2.5-fold increase from baseline or the lower limit of quantification (LLOQ) if 

Monitoring of Adverse Events in Recipients of the 2-Dose Ebola Vaccine Regimen of Ad26.ZEBOV Followed by MVA-BN-Filo in the UMURINZI Ebola Vaccination Campaign.

BACKGROUND: From 2019 to 2021, Rwandan residents of the border with the Democratic Republic of the Congo were offered the Ad26.ZEBOV (adenovirus type 26 vector vaccine encoding Ebola virus glycoprotein) and MVA-BN-Filo (modified vaccinia virus Ankara vector vaccine, encoding glycoproteins from Ebola, Sudan, Marburg, and nucleoprotein from Tai Forest viruses) Ebola vaccine regimen. METHODS: Nonpregnant persons aged ≥2 years were eligible. Unsolicited adverse events (UAEs) were reported through phone calls or visits, and serious adverse events (SAEs) were recorded per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. RESULTS: Following Ad26.ZEBOV, UAEs were reported by 0.68% of 216 113 vaccinees and were more common in younger children (aged 2-8 years, 1.2%) compared with older children (aged 9-17 years, 0.4%) and adults (aged ≥18 years, 0.7%). Fever and headache were the most reported symptoms. All 17 SAEs related to vaccine were in children aged 2-8 years (10 postvaccination febrile convulsions ± gastroenteritis and 7 fever and/or gastroenteritis). The incidence of febrile seizures was 8 of 26 062 (0.031%) prior to initiation of routine acetaminophen in December 2020 and 2 of 15 897 (0.013%) thereafter. Nonobstetric SAEs were similar in males and females. All 20 deaths were unrelated to vaccination. Young girls and adult women with UAEs were less likely to receive the second dose than those without UAEs. Seven unrelated SAEs occurred in 203 267 MVA-BN-Filo recipients. CONCLUSIONS: Postvaccination febrile convulsions in young children were rare but not previously described after Ad26.ZEBOV and were reduced with routine acetaminophen. The regimen was otherwise safe and well-tolerated.

Safety, reactogenicity, and immunogenicity of a 2-dose Ebola vaccine regimen of Ad26.ZEBOV followed by MVA-BN-Filo in healthy adult pregnant women: study protocol for a phase 3 open-label randomized controlled trial.

BACKGROUND: Risks to mother and fetus following Ebola virus infection are very high. Evaluation of safety and immunogenicity of non-replicating Ebola vaccine candidates is a priority for use in pregnant women. This is the protocol for a randomized, open-label, single-center phase 3 clinical trial of the safety, reactogenicity, and immunogenicity of the 2-dose Ebola vaccine regimen in healthy adult pregnant women. This 2-dose regimen has been shown to be safe, judged effective, and approved in non-pregnant populations. METHODS: A total of 2000 adult (≥ 18 years of age) pregnant women will be enrolled from antenatal care facilities in Western Rwanda and randomized (1:1) to receive the 2-dose Ebola vaccine regimen (Ad26.ZEBOV, MVA-BN-Filo (group A)) or control (unvaccinated pregnant women (group B)). The primary objectives are to (1) assess adverse maternal/fetal outcomes in randomized pregnant women up to 1.5 months after delivery and (2) assess adverse neonatal/infant outcomes in neonates/infants born to randomized women up to 3.5 months after birth. The frequency and relatedness of all serious adverse events in women and newborns from randomization or birth, respectively, until study end will be reported. The reactogenicity and unsolicited adverse events of the 2-dose Ebola vaccine regimen in all vaccinated pregnant women (group A) will be reported. We will also assess the immunogenicity of the 2-dose Ebola vaccine regimen in 150 pregnant women who are anticipated to receive both vaccine doses within the course of their pregnancy (a subset of the 1000 pregnant vaccinated women from group A) compared to 150 non-pregnant women vaccinated after delivery (a subset of group B). The persistence of maternal antibodies in 75 infants born to women from the group A subset will be assessed. Exploratory analyses include assessment of acceptability of the 2-dose Ebola vaccine regimen among group A and assessment of maternal antibodies in breast milk in 50 women from group A and 10 controls (women from group B prior to vaccination). DISCUSSION: This study is intended to support a label variation to relax restrictions on use in pregnant women, a vulnerable population with high medical need. TRIAL REGISTRATION: Clinicaltrials.gov NCT04556526 . September 21, 2020.

Safety and immunogenicity of 2-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccination in children and adolescents in Africa: A randomised, placebo-controlled, multicentre Phase II clinical trial.

BACKGROUND: Reoccurring Ebola outbreaks in West and Central Africa have led to serious illness and death in thousands of adults and children. The objective of this study was to assess safety, tolerability, and immunogenicity of the heterologous 2-dose Ad26.ZEBOV, MVA-BN-Filo vaccination regimen in adolescents and children in Africa. METHODS AND FINDINGS: In this multicentre, randomised, observer-blind, placebo-controlled Phase II study, 131 adolescents (12 to 17 years old) and 132 children (4 to 11 years old) were enrolled from Eastern and Western Africa and randomised 5:1 to receive study vaccines or placebo. Vaccine groups received intramuscular injections of Ad26.ZEBOV (5 × 1010 viral particles) and MVA-BN-Filo (1 × 108 infectious units) 28 or 56 days apart; placebo recipients received saline. Primary outcomes were safety and tolerability. Solicited adverse events (AEs) were recorded until 7 days after each vaccination and serious AEs (SAEs) throughout the study. Secondary and exploratory outcomes were humoral immune responses (binding and neutralising Ebola virus [EBOV] glycoprotein [GP]-specific antibodies), up to 1 year after the first dose. Enrolment began on February 26, 2016, and the date of last participant last visit was November 28, 2018. Of the 263 participants enrolled, 217 (109 adolescents, 108 children) received the 2-dose regimen, and 43 (20 adolescents, 23 children) received 2 placebo doses. Median age was 14.0 (range 11 to 17) and 7.0 (range 4 to 11) years for adolescents and children, respectively. Fifty-four percent of the adolescents and 51% of the children were male. All participants were Africans, and, although there was a slight male preponderance overall, the groups were well balanced. No vaccine-related SAEs were reported; solicited AEs were mostly mild/moderate. Twenty-one days post-MVA-BN-Filo vaccination, binding antibody responses against EBOV GP were observed in 100% of vaccinees (106 adolescents, 104 children). Geometric mean concentrations tended to be higher after the 56-day interval (adolescents 13,532 ELISA units [EU]/mL, children 17,388 EU/mL) than the 28-day interval (adolescents 6,993 EU/mL, children 8,007 EU/mL). Humoral responses persisted at least up to Day 365. A limitation of the study is that the follow-up period was limited to 365 days for the majority of the participants, and so it was not possible to determine whether immune responses persisted beyond this time period. Additionally, formal statistical comparisons were not preplanned but were only performed post hoc. CONCLUSIONS: The heterologous 2-dose vaccination was well tolerated in African adolescents and children with no vaccine-related SAEs. All vaccinees displayed anti-EBOV GP antibodies after the 2-dose regimen, with higher responses in the 56-day interval groups. The frequency of pyrexia after vaccine or placebo was higher in children than in adolescents. These data supported the prophylactic indication against EBOV disease in a paediatric population, as licenced in the EU. TRIAL REGISTRATION: ClinicalTrials.gov NCT02564523.

Steady-state pharmacokinetics of rilpivirine under different meal conditions in HIV-1-infected Ugandan adults.

OBJECTIVES: To investigate the effect of food on the steady-state pharmacokinetics of rilpivirine when administered as a fixed-dose combination tablet containing tenofovir disoproxil fumarate, emtricitabine plus rilpivirine (TDF/FTC/RPV) in HIV-1-infected Ugandan patients. METHODS: This was an open-label, three-period, longitudinal pharmacokinetic study with patients serving as their own controls. Fifteen consenting and virologically suppressed HIV-1-infected adults were switched from an efavirenz-based regimen to TDF/FTC/RPV for 56 days. Enrolled patients underwent 24 h blood sampling with TDF/FTC/RPV dosing in the fasted state (day 42), with a low-fat meal (11 g of fat/353 kcal, day 49) and with a moderate-fat meal (19 g of fat/589 kcal, day 56; reference). A viral load assessment was performed on day 56. RESULTS: Rilpivirine AUC0-24 was significantly decreased by 16% (geometric mean ratio, 90% CI: 0.84, 0.73-0.96) during administration in the fasted state when compared with AUC0-24 during administration with a moderate-fat meal. Similarly, rilpivirine C24 was significantly decreased by 21% (0.79, 0.65-0.97) in the fasted state compared with a moderate-fat meal. Pharmacokinetic parameters were unchanged during administration with a low-fat meal, except for C24, which was significantly increased by 15% (1.15, 1.01-1.31) when compared with the moderate-fat meal. Rilpivirine Cmax was similar under the three meal conditions. Virological suppression was unchanged at the end of the study. CONCLUSIONS: A food effect was observed for steady-state pharmacokinetic parameters of rilpivirine (AUC0-24 and C24) when TDF/FTC/RPV was administered in the fasted state compared with the moderate-fat meal. The TDF/FTC/RPV formulation can be administered with either a low-fat or moderate-fat meal.

Clinical presentation and aetiologies of acute or complicated headache among HIV-seropositive patients in a Ugandan clinic.

BACKGROUND: We set out to define the relative prevalence and common presentations of the various aetiologies of headache within an ambulant HIV-seropositive adult population in Kampala, Uganda. METHODS: We conducted a prospective study of adult HIV-1-seropositive ambulatory patients consecutively presenting with new onset headaches. Patients were classified as focal-febrile, focal-afebrile, non-focal-febrile or non-focal-afebrile, depending on presence or absence of fever and localizing neurological signs. Further management followed along a pre-defined diagnostic algorithm to an endpoint of a diagnosis. We assessed outcomes during four months of follow up. RESULTS: One hundred and eighty patients were enrolled (72% women). Most subjects presented at WHO clinical stages III and IV of HIV disease, with a median Karnofsky performance rating of 70% (IQR 60-80).The most common diagnoses were cryptococcal meningitis (28%, n = 50) and bacterial sinusitis (31%, n = 56). Less frequent diagnoses included cerebral toxoplasmosis (4%, n = 7), and tuberculous meningitis (4%, n = 7). Thirty-two (18%) had other diagnoses (malaria, bacteraemia, etc.). No aetiology could be elucidated in 28 persons (15%). Overall mortality was 13.3% (24 of 180) after four months of follow up. Those without an established headache aetiology had good clinical outcomes, with only one death (4% mortality), and 86% were ambulatory at four months. CONCLUSION: In an African HIV-infected ambulatory population presenting with new onset headache, aetiology was found in at least 70%. Cryptococcal meningitis and sinusitis accounted for more than half of the cases.

The spectrum of liver diseases in HIV infected individuals at an HIV treatment clinic in Kampala, Uganda.

BACKGROUND: Liver diseases are common in patients with HIV due to viral hepatitis B and C co-infections, opportunistic infections or malignancies, antiretroviral drugs and drugs for opportunistic infections. OBJECTIVE: To describe the spectrum of liver diseases in HIV-infected patients attending an HIV clinic in Kampala, Uganda. METHOD: Consecutive patients presenting with jaundice, right upper quadrant pain with fever or malaise, ascites and/or tender hepatomegaly were recruited and underwent investigations to evaluate the cause of their liver disease. RESULTS: Seventy-seven consecutive patients were recruited over an eleven month period. Of these, 23 (30%) had increased transaminases because of nevirapine (NVP) and/or isoniazid (INH) hepatotoxicity. Although 14 (61%) patients with drug-induced liver disease presented with jaundice, all recovered with drug discontinuation. Hepatitis B surface antigen was positive in 11 (15%) patients while anti-hepatitis C antibody was reactive in only 2 (3%). Probable granulomatous hepatitis due to tuberculosis was diagnosed in 7 (9%) patients and all responded to anti-TB therapy. Other diagnoses included alcoholic liver disease, AIDS cholangiopathy, hepatocellular carcinoma, schistosomiasis, haemangioma and hepatic adenoma. Twelve (16%) patients died during follow-up of which 7 (9%) died because of liver disease. CONCLUSION: Drug history, liver enzyme studies, ultrasound, and hepatitis B and C investigations identified the probable etiology in 60 (78%) of 77 patients with HIV infection presenting with symptoms and/or signs of liver disease.

Challenges in diagnosis, treatment and follow-up of patients presenting with central nervous system infections in a resource-limited setting.

Central Nervous System (CNS) infections are associated with significant mortality and morbidity. Accurate diagnosis is necessary for prompt treatment and increased chances of survival. However, there are many challenges to correct diagnoses in resource-limited settings, including the HIV epidemic, late presentation of symptomatic individuals, limited availability of laboratory diagnostic tests as well as treatment, and inadequate access to funds accompanied by lack of financial support from developed countries. This article presents case reports of patients admitted to the Mulago Hospital in Kampala, Uganda that exemplify challenging diagnoses of tuberculous meningitis (TBM), cryptococcal meningitis (CM), toxoplasmosis, and primary CNS lymphoma (PCNSL). Also included is a literature review of the pathology, diagnosis, and treatment of TBM, CM, toxoplasmosis, and PCNSL in immunocompromised patients.

First-line antiretroviral therapy in Africa--how evidence-base are our recommendations?

According to the World Health Organization guidelines, a non-nucleoside reverse transcriptase inhibitor (NNRTI) along with two nucleoside reverse transcriptase inhibitors (NRTI) is the treatment of choice as first-line antiretroviral therapy. The results of the 2NN and different cohort studies performed in developed countries do not provide sufficient evidence by which to select between nevirapine and efavirenz as the first-line NNRTI for antiretroviral therapy in Africa. The current first-line NNRTI-containing antiretroviral therapy regimens used in Africa are certainly not ideal. Nevirapine interacts with rifampicin and therefore is not indicated in patients with tuberculosis. On the other hand, efavirenz should not be given to pregnant women. NNRTI-containing regimens may be less effective in women who received nevirapine monotherapy at delivery. Stavudine, used in the nucleoside backbone, may lead to lipoatrophy, lactic acidosis and polyneuritis. Zidovudine may cause serious anemia. Mainly because of cost considerations, the generic fixed-drug combination of nevirapine plus two NRTI seems at the moment to be the best choice. It is clear, however, that antiretroviral programs should not rely only on this combination for initial antiretroviral treatment. Most importantly, more HIV clinical trials need to be conducted in Africa, and African cohorts of patients on antiretroviral therapy need to be established in order to develop recommendations that are evidence based.