Efficacy and Safety of an mRNA-Based RSV PreF Vaccine in Older Adults.

BACKGROUND: Respiratory syncytial virus (RSV) can cause substantial morbidity and mortality among older adults. An mRNA-based RSV vaccine, mRNA-1345, encoding the stabilized RSV prefusion F glycoprotein, is under clinical investigation. METHODS: In this ongoing, randomized, double-blind, placebo-controlled, phase 2-3 trial, we randomly assigned, in a 1:1 ratio, adults 60 years of age or older to receive one dose of mRNA-1345 (50 µg) or placebo. The two primary efficacy end points were the prevention of RSV-associated lower respiratory tract disease with at least two signs or symptoms and with at least three signs or symptoms. A key secondary efficacy end point was the prevention of RSV-associated acute respiratory disease. Safety was also assessed. RESULTS: Overall, 35,541 participants were assigned to receive the mRNA-1345 vaccine (17,793 participants) or placebo (17,748). The median follow-up was 112 days (range, 1 to 379). The primary analyses were conducted when at least 50% of the anticipated cases of RSV-associated lower respiratory tract disease had occurred. Vaccine efficacy was 83.7% (95.88% confidence interval [CI], 66.0 to 92.2) against RSV-associated lower respiratory tract disease with at least two signs or symptoms and 82.4% (96.36% CI, 34.8 to 95.3) against the disease with at least three signs or symptoms. Vaccine efficacy was 68.4% (95% CI, 50.9 to 79.7) against RSV-associated acute respiratory disease. Protection was observed against both RSV subtypes (A and B) and was generally consistent across subgroups defined according to age and coexisting conditions. Participants in the mRNA-1345 group had a higher incidence than those in the placebo group of solicited local adverse reactions (58.7% vs. 16.2%) and of systemic adverse reactions (47.7% vs. 32.9%); most reactions were mild to moderate in severity and were transient. Serious adverse events occurred in 2.8% of the participants in each trial group. CONCLUSIONS: A single dose of the mRNA-1345 vaccine resulted in no evident safety concerns and led to a lower incidence of RSV-associated lower respiratory tract disease and of RSV-associated acute respiratory disease than placebo among adults 60 years of age or older. (Funded by Moderna; ConquerRSV ClinicalTrials.gov number, NCT05127434.).

Safety and Immunogenicity of an mRNA-Based RSV Vaccine Including a 12-Month Booster in a Phase I Clinical Trial in Healthy Older Adults.

BACKGROUND: An mRNA-based RSV vaccine, mRNA-1345, is under clinical investigation to address RSV disease burden in older adults. METHODS: This phase 1, randomized, observer-blind, placebo-controlled, dose-ranging study evaluated safety, reactogenicity, and immunogenicity of mRNA-1345 in adults 65-79 years (NCT04528719). Participants were randomized to receive 1-dose of mRNA-1345 (12.5, 25, 50, 100, or 200-µg) or placebo and matched mRNA-1345 booster or placebo at 12-months. RESULTS: Overall, 298 participants received the first injection; 247 received the 12-month booster injection. mRNA-1345 was generally well-tolerated after both injections, with the most frequently reported solicited adverse reactions being injection-site pain, fatigue, headache, arthralgia, and myalgia. Reactogenicity was higher after the booster injection than the first injection but similar severity, time-to-onset, and duration. A single mRNA-1345 injection boosted RSV-A and RSV-B neutralizing antibody titers (nAb) and prefusion-F-binding antibody (preF-bAb) concentrations at 1-month (geometric mean-fold rises: RSV-A, 10.2-16.5; RSV-B, 5.3-12.5; preF-bAb, 7.2-12.1). RSV antibody levels remained above baseline through 12-months, indicating immune persistence. A 12-month booster injection also increased RSV-A and RSV-B nAb titers and preF-bAb concentrations; titers post-booster injection were numerically lower compared to titers after the first-dose, with overlapping 95% CIs. CONCLUSIONS: mRNA-1345 was well-tolerated and immunogenic following a single injection and a 12-month booster. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04528719.

Safety, Tolerability and Immunogenicity of a mRNA-based RSV Vaccine in Healthy Young Adults in a Phase 1 Clinical Trial.

BACKGROUND: Respiratory syncytial virus (RSV) presents a global health concern. A lipid nanoparticle-encapsulated mRNA-based RSV vaccine (mRNA-1345) encoding the membrane-anchored RSV prefusion stabilised F glycoprotein (preF) is under clinical investigation. METHODS: This phase 1, randomized, observer-blind, placebo-controlled dose escalation study assessed safety and immunogenicity of mRNA-1345 in healthy adults aged 18-49 years (NCT04528719). Participants were randomized to receive one dose of mRNA-1345 (50, 100, or 200 µg) or placebo, or 3 doses of mRNA-1345 (100 µg) or placebo 56 days apart. RESULTS: mRNA-1345 was well-tolerated at all dose levels. The most common solicited adverse reactions were pain, headache, fatigue, myalgia, or chills, which were all generally mild to moderate. A single injection of mRNA-1345 boosted RSV neutralizing antibody titers (geometric mean fold rise [GMFR]: RSV-A, 20.0 to 23.5; RSV-B, 11.7 to 16.0) and RSV preF binding antibody concentrations (GMFR: 16.1 to 21.8) at 1 month post injection, with no apparent dose response. Antibody levels remained above baseline through 6 months. Sequential doses of 100 µg were well tolerated but did not further boost antibody levels. CONCLUSIONS: A single mRNA-1345 injection demonstrated an acceptable safety profile in younger adults and induced a durable neutralizing antibody response, supporting its continued development.

Safety and Immunogenicity of an mRNA-Based hMPV/PIV3 Combination Vaccine in Seropositive Children.

OBJECTIVES: Human metapneumovirus (hMPV) and parainfluenza virus type 3 (PIV3) are common respiratory illnesses in children. The safety and immunogenicity of an investigational mRNA-based vaccine, mRNA-1653, encoding membrane-anchored fusion proteins of hMPV and PIV3, was evaluated in hMPV/PIV3-seropositive children. METHODS: In this phase 1b randomized, observer-blind, placebo-controlled, dose-ranging study, hMPV/PIV3-seropositive children were enrolled sequentially into 2 dose levels of mRNA-1653 administered 2 months apart; children aged 12 to 36 months were randomized (1:1) to receive 10-µg of mRNA-1653 or placebo and children aged 12 to 59 months were randomized (3:1) to receive 30-µg of mRNA-1653 or placebo. RESULTS: Overall, 27 participants aged 18 to 55 months were randomized; 15 participants received 10-µg of mRNA-1653 (n = 8) or placebo (n = 7), whereas 12 participants received 30-µg of mRNA-1653 (n = 9) or placebo (n = 3). mRNA-1653 was well-tolerated at both dose levels. The only reported solicited local adverse reaction was tenderness at injection site; solicited systemic adverse reactions included grade 1 or 2 chills, irritability, loss of appetite, and sleepiness. A single 10-µg or 30-µg mRNA-1653 injection increased hMPV and PIV3 neutralizing antibody titers (geometric mean fold-rise ratio over baseline: hMPV-A = 2.9-6.1; hMPV-B = 6.2-13.2; PIV3 = 2.8-3.0) and preF and postF binding antibody concentrations (geometric mean fold-rise ratio: hMPV preF = 5.3-6.1; postF = 4.6-6.5 and PIV3 preF = 13.9-14.2; postF = 11.0-12.1); a second injection did not further increase antibody levels in these seropositive children. Binding antibody responses were generally preF biased. CONCLUSIONS: mRNA-1653 was well-tolerated and boosted hMPV and PIV3 antibody levels in seropositive children aged 12 to 59 months, supporting the continued development of mRNA-1653 or its components for the prevention of hMPV and PIV3.

Neuroprotective effects of zinc on antioxidant defense system in lithium treated rat brain.

With a view to find out whether zinc affords protection against lithium toxicity the activities of antioxidant enzymes and lipid peroxidation profile were determined in the cerebrum and cerebellum of lithium treated female Sprague Dawley rats. Lipid peroxidation was significantly increased in both the cerebrum and the cerebellum of animals administered with lithium for a total duration of 4 months as compared to the normal control group. On the contrary, the activities of catalase and glutathione-s-transferase (GST) were significantly reduced after 4 months of lithium treatment. The activity of superoxide dismutase (SOD) was significantly increased in the cerebrum after 4 months lithium administration, whereas in the cerebellum the enzyme activity was unaffected. No significant change in the levels of reduced glutathione (GSH) was found in either cerebrum or cerebellum after 2 months of lithium treatment. However, 4 months lithium treatment did produce significant changes in GSH levels in the cerebrum and in the cerebellum. Zinc supplementation for 4 months in lithium-treated rats significantly increased the activities of catalase and GST in the cerebellum, showing that the treatment with zinc reversed the lithium induced depression in these enzyme activities. Though, zinc treatment tended to normalize the SOD activity in the cerebrum yet it was still significantly higher in comparison to normal levels. From the present study, it can be concluded that the antiperoxidative property of zinc is effective in reversing the oxidative stress induced by lithium toxicity in the rat brain.