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 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 a Shigella Bivalent Conjugate Vaccine (ZF0901) in 3-Month- to 5-Year-Old Children in China

No licensed Shigella vaccine is presently available globally. A double-blinded, randomized, placebo-controlled, age descending phase II clinical trial of a bivalent conjugate vaccine was studied in China. The vaccine ZF0901 consisted of O-specific polysaccharides purified and detoxified from lipopolysaccharide (LPS) of S. flexneri 2a and S. sonnei and covalently bonded to tetanus toxoid. A total of 224, 310, and 434 children, consented by parents or guardians, aged 3 to 6 and 6 to 12 months and 1 to 5 years old, respectively, were injected with half or full doses, with or without adjuvant or control Hib vaccine. There were no serious adverse reactions in all recipients of ZF0901 vaccine independent of age, dosage, number of injections, or the adjuvant status. Thirty days after the last injection, ZF0901 induced robust immune responses with significantly higher levels of type-specific serum antibodies (geometric mean concentrations (GMCs) of IgG anti-LPS) against both serotypes in all age groups compared with the pre-immune or the Hib control (p < 0.0001). Here, we demonstrated that ZF0901 bivalent Shigella conjugate vaccine is safe and immunogenic in infants and young children and is likely suitable for routine immunization.

The immunogenicity and safety of respiratory syncytial virus vaccines in development: A systematic review

Background

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory infection globally. There are vaccine candidates in development, but a systematic review on immunogenicity and safety of vaccine is lacking.

Methods

This systematic review of RSV vaccine clinical trials was undertaken using four databases. Searches were conducted using both controlled vocabulary terms such as “Respiratory Syncytial Virus, Human,” “Respiratory Syncytial Virus Infections,” “Respiratory Syncytial Virus Vaccines,” “Immunization,” “Immunization Programs” and “Vaccines” and corresponding text word terms. The included studies were limited to clinical trials published from January 2000 to 31 December 2020. RSV infection case was defined as RSV‐associated medically attended acute respiratory illness (MAARI) or RSV infection by serologically confirmed test (Western blot) during the RSV surveillance period. We calculated the relative risk of each vaccine trial with RSV infection case.

Results

Of 6306 publications, 38 were included and data were extracted covering four major types of RSV vaccine candidates, these being live‐attenuated/chimeric (n = 14), recombinant‐vector (n = 6), subunit (n = 12) and nanoparticle vaccines (n = 6). For RSV infection cases, nine trials were involved and none of them showed a vaccine‐related increased MAARI during RSV surveillance season.

Conclusion

LID ∆M2‐2, MEDI M2‐2, RSVcps2 and LID/∆M2‐2 /1030s (live‐attenuated) were considered the most promising vaccine candidates in infant and children. In the elderly, a nanoparticle F vaccine candidate and Ad26.RSV.preF were considered as two potential effective vaccines. A promising maternal vaccine candidate is still lacking.

Safety and Immunogenicity of the GamTBvac, the Recombinant Subunit Tuberculosis Vaccine Candidate: A Phase II, Multi-Center, Double-Blind, Randomized, Placebo-Controlled Study

GamTBvac is a candidate tuberculosis vaccine with two fusion proteins, containing Ag85a, ESAT6, CFP10, and a dextran-binding domain (DBD). Phase II of a double-blind, randomized, multicenter, placebo-controlled study in parallel groups in healthy adults to evaluate the safety and immunogenicity of GamTBvac in 180 previously-vaccinated with Bacillus Calmette-Guérin vaccine (BCG) healthy volunteers without Mycobacterium tuberculosis (MTB) infection was conducted. The dose (0.5 mL) of either the study drug or a placebo was administered subcutaneously twice with an 8-week interval. At eight timepoints from 14 to 150 days, whole blood and sera were assayed. Antigen-specific T-cell responses were measured by an in-house interferon-gamma release assay (IGRA-test), the QuantiFERON (QTF) test, and intracellular cytokine staining (ICS). For antibody response detection, the bead-based multiplex immunoassay (MIA) was applied. The vaccine confirmed an acceptable safety profile previously shown in a first-in-human clinical study. After stimulation with both fusions, the highest median level of INF-γ was detected on day 21. The GamTBvac vaccine induced antigen-specific interferon-gamma release, Th1 cytokine-expressing CD4⁺ T-cells, and IgG responses and results support further clinical testing of GamTBvac.

First-In-Human Trials of GamTBvac, a Recombinant Subunit Tuberculosis Vaccine Candidate: Safety and Immunogenicity Assessment

Tuberculosis is known to be the biggest global health problem, causing the most deaths by a single infectious agent. Vaccine-development efforts are extremely important. This paper represents the results of the first-in-human trial of recombinant subunit tuberculosis vaccine GamTBvac in a Phase I study. GamTBvac is a new BCG booster candidate vaccine containing dextran-binding domain modified Ag85a and ESAT6-CFP10 MTB antigens and CpG ODN adjuvant, formulated with dextrans. Safety and immunogenicity of GamTBvac were estimated in an open-label clinical trial on 60 Mycobacterium tuberculosis uninfected (MTB-uninfected) volunteers previously-vaccinated with Bacillus Calmette—Guérin vaccine (BCG). The candidate vaccine had an acceptable safety profile and was well-tolerated. Three different vaccine doses with a double-immunization scheme were assessed for immunogenicity and induced a significant increase in IFN-γ in-house IGRA response and IgG ELISA analysis. Among them, the half dose vaccine group (containing DBD-ESAT6-CFP10, 12.5 μg; DBD-Ag85a, 12.5 μg; CpG (ODN 2216), 75 μg; DEAE-Dextran 500 kDa, 250 μg; and Dextran 500 kDa, 5 mg) provided high, early and stable in time immune response specific to both protein antigen fusions and is proposed for the further studies.

Safety and Immunogenicity of a 2-Dose Heterologous Vaccination Regimen With Ad26.ZEBOV and MVA-BN-Filo Ebola Vaccines: 12-Month Data From a Phase 1 Randomized Clinical Trial in Uganda and Tanzania

BACKGROUND

Ebola vaccine development was accelerated in response to the 2014 Ebola virus infection outbreak. This phase 1 study (VAC52150EBL1004) assessed safety, tolerability, and immunogenicity of heterologous 2-dose Ad26.ZEBOV, MVA-BN-Filo vaccination regimens in the Lake Victoria Basin of Tanzania and Uganda in mid-level altitude, malaria-endemic settings.

METHODS

Healthy volunteers aged 18-50 years from Tanzania (n = 25) and Uganda (n = 47) were randomized to receive placebo or active vaccination with Ad26.ZEBOV or MVA-BN-Filo (first vaccination), followed by MVA-BN-Filo or Ad26.ZEBOV (second vaccination) dose 2, respectively, with intervals of 28 or 56 days.

RESULTS

Seventy-two adults were randomized to receive vaccine (n = 60) or placebo (n = 12). No vaccine-related serious adverse events were reported. The most frequent solicited local and systemic adverse events were injection site pain (frequency, 70%, 66%, and 42% per dose for MVA-BN-Filo, Ad26.ZEBOV, and placebo, respectively) and headache (57%, 56%, and 46%, respectively). Adverse event patterns were similar among regimens. Twenty-one days after dose 2, 100% of volunteers demonstrated binding antibody responses against Ebola virus glycoprotein, and 87%-100% demonstrated neutralizing antibody responses. Ad26.ZEBOV dose 1 vaccination induced more-robust initial binding antibody and cellular responses than MVA-BN-Filo dose 1 vaccination.

CONCLUSIONS

Heterologous 2-dose vaccination with Ad26.ZEBOV and MVA-BN-Filo against Ebola virus is well tolerated and immunogenic in healthy volunteers.

CLINICAL TRIALS REGISTRATION

NCT02376400.

Safety and Immunogenicity of a 2-Dose Heterologous Vaccine Regimen With Ad26.ZEBOV and MVA-BN-Filo Ebola Vaccines: 12-Month Data From a Phase 1 Randomized Clinical Trial in Nairobi, Kenya

BACKGROUND

During the 2014 West African Ebola outbreak, Ebola vaccine development was accelerated. The phase 1 VAC52150EBL1003 study was performed to investigate 2-dose heterologous vaccination with Ad26.ZEBOV and MVA-BN-Filo in an African population located in a high-altitude setting in Nairobi, Kenya.

METHODS

Healthy adult volunteers were randomized to receive one of four 2-dose vaccination schedules. The first vaccination was administered at baseline (Ad26.ZEBOV or MVA-BN-Filo), followed by the second vaccination with the alternate vaccine after either 28 or 56 days. Each schedule had a placebo comparator group. The primary objective was to assess the safety and tolerability of these regimens.

RESULTS

Seventy-two volunteers were randomized into 4 groups of 18 (15 received vaccine, and 3 received placebo). The most frequent solicited systemic adverse event was headache (frequency, 50%, 61%, and 42% per dose for MVA-BN-Filo, Ad26.ZEBOV, and placebo, respectively). The most frequent solicited local AE was injection site pain (frequency, 78%, 63%, and 33% per dose for MVA-BN-Filo, Ad26.ZEBOV, and placebo, respectively). No differences in adverse events were observed among the different vaccine regimens. High levels of binding and neutralizing anti-Ebola virus glycoprotein antibodies were induced by all regimens and sustained to day 360 after the first dose.

CONCLUSIONS

Two-dose heterologous vaccination with Ad26.ZEBOV and MVA-BN-Filo was well tolerated and highly immunogenic against Ebola virus glycoprotein.

CLINICAL TRIALS REGISTRATION

NCT02376426.

Pertussis vaccination in pregnancy

Pertussis has had a resurgence with the highest incidence and complication rates in young infants, and deaths occurring mainly at < age 3 months. Infants are infected by older individuals whose immunity has waned. Strategies such as targeted immunization of infant caregivers have had limited success. Pertussis vaccination in pregnancy may protect infants through passive and active transfer of maternal antibodies that protect the infant until the primary immunization series. Studies show vaccinating pregnant women with acellular pertussis vaccine is safe for mother and infant, immunogenic with efficient transfer of antibodies to infants, and effective in preventing pertussis in young infants. Vaccine uptake in pregnant women is sub-optimal, but provider recommendation is the most important factor in improving vaccination rates. Studies are ongoing to determine the best timing of vaccination to protect infants, and into other strategies. Vaccinating pregnant women offers hope to prevent pertussis-related morbidity and mortality in infants worldwide.

Safety, reactogenicity and immunogenicity of Francisella tularensis live vaccine strain in humans

We evaluated the safety, reactogenicity and immunogenicity of escalating doses of a new Francisella tularensis Live Vaccine Strain (LVS) lot by scarification (SCAR) or subcutaneously (SQ) in humans. Subjects (N=10/group) received one dose of LVS via SCAR at 10(5),10(7) or 10(9)cfu/ml or SQ at 10(2), 10(3),10(4) or 10(5)cfu/ml; 14 subjects received placebo. All doses/routes were well tolerated. When compared to placebo, vaccination with 10(7) SCAR and 10(9) SCAR resulted in significantly higher serologic response frequencies, as measured by ELISA for IgG, IgM, IgA and microagglutination; whereas vaccination with 10(5) SCAR, 10(7) SCAR 10(9) SCAR and 10(5) SQ elicited a significantly higher interferon-gamma response frequency.