Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant.

BACKGROUND: Assessment of the safety and efficacy of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in different populations is essential, as is investigation of the efficacy of the vaccines against emerging SARS-CoV-2 variants of concern, including the B.1.351 (501Y.V2) variant first identified in South Africa. METHODS: We conducted a multicenter, double-blind, randomized, controlled trial to assess the safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) in people not infected with the human immunodeficiency virus (HIV) in South Africa. Participants 18 to less than 65 years of age were assigned in a 1:1 ratio to receive two doses of vaccine containing 5×1010 viral particles or placebo (0.9% sodium chloride solution) 21 to 35 days apart. Serum samples obtained from 25 participants after the second dose were tested by pseudovirus and live-virus neutralization assays against the original D614G virus and the B.1.351 variant. The primary end points were safety and efficacy of the vaccine against laboratory-confirmed symptomatic coronavirus 2019 illness (Covid-19) more than 14 days after the second dose. RESULTS: Between June 24 and November 9, 2020, we enrolled 2026 HIV-negative adults (median age, 30 years); 1010 and 1011 participants received at least one dose of placebo or vaccine, respectively. Both the pseudovirus and the live-virus neutralization assays showed greater resistance to the B.1.351 variant in serum samples obtained from vaccine recipients than in samples from placebo recipients. In the primary end-point analysis, mild-to-moderate Covid-19 developed in 23 of 717 placebo recipients (3.2%) and in 19 of 750 vaccine recipients (2.5%), for an efficacy of 21.9% (95% confidence interval [CI], -49.9 to 59.8). Among the 42 participants with Covid-19, 39 cases (95.1% of 41 with sequencing data) were caused by the B.1.351 variant; vaccine efficacy against this variant, analyzed as a secondary end point, was 10.4% (95% CI, -76.8 to 54.8). The incidence of serious adverse events was balanced between the vaccine and placebo groups. CONCLUSIONS: A two-dose regimen of the ChAdOx1 nCoV-19 vaccine did not show protection against mild-to-moderate Covid-19 due to the B.1.351 variant. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT04444674; Pan African Clinical Trials Registry number, PACTR202006922165132).

Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant.

BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the coronavirus disease 2019 (Covid-19) pandemic. In a phase 1-2 trial involving healthy adults, the NVX-CoV2373 nanoparticle vaccine had an acceptable safety profile and was associated with strong neutralizing-antibody and antigen-specific polyfunctional CD4+ T-cell responses. Evaluation of vaccine efficacy was needed in a setting of ongoing SARS-CoV-2 transmission. METHODS: In this phase 2a-b trial in South Africa, we randomly assigned human immunodeficiency virus (HIV)-negative adults between the ages of 18 and 84 years or medically stable HIV-positive participants between the ages of 18 and 64 years in a 1:1 ratio to receive two doses of either the NVX-CoV2373 vaccine (5 µg of recombinant spike protein with 50 µg of Matrix-M1 adjuvant) or placebo. The primary end points were safety and vaccine efficacy against laboratory-confirmed symptomatic Covid-19 at 7 days or more after the second dose among participants without previous SARS-CoV-2 infection. RESULTS: Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, -0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups. CONCLUSIONS: The NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT04533399.).

Immunogenicity and safety of the 13-valent pneumococcal conjugate vaccine in HIV-infected individuals naive to pneumococcal vaccination.

OBJECTIVE: Immunocompromised individuals are at an increased risk of pneumococcal disease. Vaccination is recommended as an important strategy to reduce risk of pneumococcal disease in HIV-infected individuals. This study evaluated the safety and immunogenicity of three 13-valent pneumococcal conjugate vaccine (PCV13) doses followed by one dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23) at 1-month intervals in pneumococcal vaccine-naive, HIV-infected individuals. DESIGN: This was a phase 3, open-label, single-arm study. METHODS: Pneumococcal vaccine-naive, HIV-infected individuals at least 6 years of age with CD4 T-cell count at least 200  cells/µl and viral load less than 50 000  copies/ml received three doses of PCV13 followed by one dose of PPSV23 at 1-month intervals. Serotype-specific antipneumococcal immune responses were assessed by IgG geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) assay geometric mean titres (GMTs) after each dose. Local reactions at the PCV13 injection site, systemic and other adverse events were collected. RESULTS: Three hundred and one individuals were enrolled and vaccinated; 279 completed the study. Statistically significant increases in IgG GMCs and OPA GMTs were observed for all serotypes after dose 1 of PCV13 compared with prevaccine levels. GMCs and GMTs were comparable or only modestly increased for all serotypes after PCV13 doses 2 and 3 and after PPSV23. The majority of local reactions and systemic events were mild to moderate in severity. CONCLUSION: A three-dose regimen of PCV13 was well tolerated in pneumococcal vaccine-naive, HIV-infected individuals. Significant immune responses to all serotypes were observed following the first dose of PCV13, with only modest increases in antibody titres following subsequent PCV13 or PPSV23 administration.

A double-blind, dose-response study of the efficacy and safety of olmesartan medoxomil in children and adolescents with hypertension.

The current study investigated the efficacy and safety of olmesartan medoxomil in children with hypertension, defined as systolic blood pressure measured at or above the 95th percentile (90th percentile for patients with diabetes, glomerular kidney disease, or family history of hypertension) for age, gender, and height while off any antihypertensive medication. The active treatment phase was conducted in 2 periods, with 2 cohorts in each period (cohort A, 62% white; cohort B, 100% Black). In period 1, patients stratified by weight received low-dose (2.5 or 5 mg) or high-dose (20 or 40 mg) olmesartan medoxomil daily for 3 weeks. In period 2, patients maintained their olmesartan medoxomil dose or initiated placebo washout for an additional 2 weeks. Period 1 efficacy results showed a dose-dependent, statistically significant reduction in seated trough systolic and diastolic blood pressure for both cohorts, with mean blood pressure reductions numerically smaller in cohort B than in cohort A. The olmesartan medoxomil dose response remained statistically significant when adjusted for body weight. In period 2, blood pressure control decreased in those patients switching to placebo, whereas patients continuing to receive olmesartan medoxomil therapy maintained consistent blood pressure reduction. Adverse events were generally mild and unrelated to study medication. Olmesartan medoxomil was safe and efficacious in children with hypertension, resulting in significant blood pressure reductions.