•mRNA vaccines may provide timely and effective responses to threats from emerging pathogens.•We assessed mRNA vaccines against 2 highly pathogenic avian influenza strains.•The first mRNA N10N8 and ...H7N9 influenza vaccines are safe and immunogenic.
We evaluated safety and immunogenicity of the first mRNA vaccines against potentially pandemic avian H10N8 and H7N9 influenza viruses.
Two randomized, placebo-controlled, double-blind, phase 1 clinical trials enrolled participants between December 2015 and August 2017 at single centers in Germany (H10N8) and USA (H7N9). Healthy adults (ages 18–64 years for H10N8 study; 18–49 years for H7N9 study) participated. Participants received vaccine or placebo in a 2-dose vaccination series 3 weeks apart. H10N8 intramuscular (IM) dose levels of 25, 50, 75, 100, and 400 µg and intradermal dose levels of 25 and 50 µg were evaluated. H7N9 IM 10-, 25-, and 50-µg dose levels were evaluated; 2-dose series 6 months apart was also evaluated. Primary endpoints were safety (adverse events) and tolerability. Secondary immunogenicity outcomes included humoral (hemagglutination inhibition HAI, microneutralization MN assays) and cell-mediated responses (ELISPOT assay).
H10N8 and H7N9 mRNA IM vaccines demonstrated favorable safety and reactogenicity profiles. No vaccine-related serious adverse event was reported. For H10N8 (N = 201), 100-µg IM dose induced HAI titers ≥ 1:40 in 100% and MN titers ≥ 1:20 in 87.0% of participants. The 25-µg intradermal dose induced HAI titers > 1:40 in 64.7% of participants compared to 34.5% of participants receiving the IM dose. For H7N9 (N = 156), IM doses of 10, 25, and 50 µg achieved HAI titers ≥ 1:40 in 36.0%, 96.3%, and 89.7% of participants, respectively. MN titers ≥ 1:20 were achieved by 100% in the 10- and 25-µg groups and 96.6% in the 50-µg group. Seroconversion rates were 78.3% (HAI) and 87.0% (MN) for H10N8 (100 µg IM) and 96.3% (HAI) and 100% (MN) in H7N9 (50 µg). Significant cell-mediated responses were not detected in either study.
The first mRNA vaccines against H10N8 and H7N9 influenza viruses were well tolerated and elicited robust humoral immune responses.
ClinicalTrials.gov NCT03076385 and NCT03345043.
Respiratory Syncytial Virus (RSV) causes lower respiratory tract infections that can be severe and sometimes fatal. The risk for severe RSV infection is highest in infants and older adults. A safe ...and effective RSV vaccine for older adults represents a serious unmet medical need due to higher morbidity and mortality in this age group. In this randomized, partially double-blind, placebo-controlled, phase 1 dose-escalation study, we evaluated the safety, tolerability and immunogenicity of an investigational messenger ribonucleic acid (mRNA) vaccine encoding the RSV fusion protein (F) stabilized in the prefusion conformation. The study was conducted in healthy younger adults (ages ≥18 and ≤49 years) and healthy older adults (ages ≥60 and ≤79 years). Participants received mRNA-1777 (V171) or placebo as a single intramuscular dose. For each dose level, three sentinel participants were administered open-label mRNA-1777 (V171). Seventy-two younger adults were randomized and administered 25, 100, or 200 µg mRNA-1777 (V171) or placebo, and 107 older adults were randomized and administered 25, 100, 200 or 300 µg mRNA-1777 (V171) or placebo. Primary objectives were safety and tolerability and secondary objectives included humoral and cell-mediated immunogenicity. All dose levels of mRNA-1777 (V171) were generally well tolerated and no serious adverse events related to the vaccine were reported. Immunization with mRNA-1777 (V171) elicited a humoral immune response as measured by increases in RSV neutralizing antibody titers, serum antibody titers to RSV prefusion F protein, D25 competing antibody titers to RSV prefusion F protein, and cell-mediated immune responses to RSV-F peptides.
There is a need for improved production of the influenza vaccine, including a shorter time from antigen identification to vaccine availability and minimization of the development of egg-adapted ...mutations. In a trial involving healthy children, a cell-culture–derived quadrivalent influenza vaccine had efficacy against the circulating influenza serotypes.
Meningococcal disease continues to be a major cause of illness globally. In this report from Mali, a new meningococcal vaccine, which includes a fifth serotype, X, was shown to elicit higher antibody ...titers than a standard meningococcal vaccine.
BACKGROUND:Rotavirus disease is more severe in preterm infants than in full-term infants. This study assessed the safety, reactogenicity and immunogenicity of a human rotavirus vaccine, RIX4414, in ...European preterm infants.
METHODS:A total of 1009 preterm infants were randomized (2:1, vaccine:placebo) and stratified into 2 groups20% of early (27–30 weeks, group 1) and 80% of late (31–36 weeks, group 2) gestational age preterm infants in each group. Two doses of RIX4414/placebo were administered to these preterm infants according to the recommended chronologic age for full-term infants with an interval of 30–83 days between doses. Serious adverse events were recorded throughout the study period. Solicited and unsolicited adverse events were recorded for 15 and 31 days post-each dose. Antirotavirus IgA concentrations (enzyme-linked immunosorbent assay cutoff = 20 U/mL) and geometric mean concentration were determined pre-dose 1 and 30–83 days post-dose 2 in a subset of 300 infants. This study is registered with ClinicalTrials.gov, number NCT00420745 (eTrack106481).
RESULTS:Serious adverse events were reported at a similar frequency in both groups (P = 0.266). Fifty-seven infants reported at least 1 serious adverse event (5.1% 3.5–7.0 in the RIX4414 group and 6.8% 4.3–10.0 in the placebo group). During the 15-day postvaccination follow-up period, diarrhea, vomiting and fever occurred at a similar frequency in both groups; fever could have been due to concomitant vaccines. Five cases (RIX4414 = 3, Placebo = 2) of rotavirus gastroenteritis were reported. The onset of rotavirus gastroenteritis in the RIX4414 group was 1–5 days after vaccination (vaccine strain identified in all cases) and in the placebo group it was 3–4 days after receiving placebo (wild-type rotavirus identified from both cases). Antirotavirus IgA seroconversion rates at 30–83 days post-dose 2 were 85.7% (79.0–90.9) in the RIX4414 group and 16.0% (8.8–25.9) in the placebo group. Geometric mean concentrations were 202.2 U/mL (153.1–267.1) in the RIX4414 group and <20 U/mL in the placebo group. Seroconversion rate in groups 1 and 2 in RIX4414 recipients were 75.9% (95% confidence interval CI56.5–89.7%) and 88.1% (95% CI80.9–93.4%), respectively; the geometric mean concentrations in the respective groups were 110.2 U/mL (95% CI56.1–216.5) and 234.8 U/mL (95% CI173.4–318.0; exploratory analysis).
CONCLUSIONS:Two doses of RIX4414 were immunogenic and well-tolerated in European preterm infants.
Highlights ► Efficacy results during the first three years of life and individual year follow-up periods of infants participating in this Asian study is reported. ► Efficacy against severe RVGE was ...96.9% (95% CI 88.3–99.6) over the first three years of life and 100% (67.5–100) in RIXX4414 in the third-year. ► RIX4414 was efficacious against G1 (100.0% 84.8–100) and pooled non-G1 RV types (94.9% 80.2–99.4).
Combination of waning immunity and lower effectiveness against new SARS-CoV-2 variants of approved COVID-19 vaccines necessitates new vaccines. We evaluated two doses, 28 days apart, of ARCT-154, a ...self-amplifying mRNA COVID-19 vaccine, compared with saline placebo in an integrated phase 1/2/3a/3b controlled, observer-blind trial in Vietnamese adults (ClinicalTrial.gov identifier: NCT05012943). Primary safety and reactogenicity outcomes were unsolicited adverse events (AE) 28 days after each dose, solicited local and systemic AE 7 days after each dose, and serious AEs throughout the study. Primary immunogenicity outcome was the immune response as neutralizing antibodies 28 days after the second dose. Efficacy against COVID-19 was assessed as primary and secondary outcomes in phase 3b. ARCT-154 was well tolerated with generally mild-moderate transient AEs. Four weeks after the second dose 94.1% (95% CI: 92.1-95.8) of vaccinees seroconverted for neutralizing antibodies, with a geometric mean-fold rise from baseline of 14.5 (95% CI: 13.6-15.5). Of 640 cases of confirmed COVID-19 eligible for efficacy analysis most were due to the Delta (B.1.617.2) variant. Efficacy of ARCT-154 was 56.6% (95% CI: 48.7- 63.3) against any COVID-19, and 95.3% (80.5-98.9) against severe COVID-19. ARCT-154 vaccination is well tolerated, immunogenic and efficacious, particularly against severe COVID-19 disease.
We assessed the non-inferiority of homologous boosting compared with heterologous boosting with the recombinant protein vaccine, SCB-2019, in adults previously immunized with different COVID-19 ...vaccines. Three equal cohorts (N ~ 420) of Philippino adults (18-80 years) previously immunized with Comirnaty, CoronaVac or Vaxzevria COVID-19 vaccines were randomized 1:1 to receive homologous or heterologous (SCB-2019) boosters. Neutralizing antibodies against prototype SARS-CoV-2 (Wuhan-Hu-1) were measured in all participants and against Delta variant and Omicron sub-lineages in subsets (30‒50 per arm) 15 days after boosting. Participants recorded solicited adverse events for 7 days and unsolicited and serious adverse events until Day 60. Prototype SARS-CoV-2 neutralizing responses on Day 15 after SCB-2019 were statistically non-inferior to homologous Vaxzevria boosters, superior to CoronaVac, but lower than homologous Comirnaty. Neutralizing responses against Delta and Omicron BA.1, BA.2, BA.4 and BA.5 variants after heterologous SCB-2019 were higher than homologous CoronaVac or Vaxzevria, but lower than homologous Comirnaty. Responses against Omicron BF.7, BQ.1.1.3, and XBB1.5 following heterologous SCB-2019 were lower than after homologous Comirnaty booster but significantly higher than after Vaxzevria booster. SCB-2019 reactogenicity was similar to CoronaVac or Vaxzevria, but lower than Comirnaty; most frequent events were mild/moderate injection site pain, headache and fatigue. No vaccine-related serious adverse events were reported. Heterologous SCB-2019 boosting was well tolerated and elicited neutralizing responses against all tested SARS-COV-2 viruses including Omicron BA.1, BA.2, BA.4, BA.5, BF.7, BQ.1.1.3, and XBB1.5 sub-lineages that were non-inferior to homologous boosting with CoronaVac or Vaxzevria, but not homologous Comirnaty booster.
Abstract A phase III, randomized, double-blind study evaluated the efficacy, reactogenicity, safety and immunogenicity of a human rotavirus vaccine, RIX4414 in Japanese infants aged 6–14 weeks when ...administered as two doses (0, 1-month schedule). Efficacy against any and severe rotavirus gastroenteritis leading to medical intervention caused by circulating wild-type rotavirus from two weeks post-Dose 2 until two years of age was 79.3% (95% CI: 60.5–89.8%) and 91.6% (95% CI: 62.4–99.1%), respectively. Solicited, unsolicited symptoms and serious adverse events were reported at a similar frequency in both groups. Serum anti-rotavirus antibody seroconversion rate one-month post-Dose 2 was 85.3% (95% CI: 68.9–95%) in RIXX4414 group. RIX4414 was efficacious, well-tolerated and immunogenic in Japanese infants and introduction of vaccination could help in reducing the disease burden.
Highlights ► Transmission of excreted vaccine-derived infectious virus from vaccinated to unvaccinated individuals was assessed. ► Presence of vaccine strain in the stool samples of placebo ...recipients was an indicator of transmission. ► Immunogenicity and safety of HRV vaccine in transmission cases was assessed. ► Transmission rate was 18.8%; however, they were not associated with increased risk of gastroenteritis.
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