A Phase1 Results of a Non-Stabilized Spike-Encoding mRNA Vaccine in Adults

BackgroundEffective COVID-19 mRNA vaccines are mainly available in high-income countries. ChulaCov19, a prefusion non-stabilized Spike protein-encoding, nucleoside-modified mRNA, lipid nanoparticle encapsulated vaccine development, aims to enhance accessibility of mRNA vaccine and future pandemic preparedness for low- to middle-income countries. MethodsSeventy-two eligible volunteers, 36 aged 18-55 (adults) followed by 36 aged 56-75 (elderly) enrolled in a dose escalation study of ChulaCov19 mRNA vaccine. Two doses of vaccine were given 21 days apart at 10, 25, or 50 {micro}g/dose (12/group). Safety was the primary and immunogenicity the secondary outcome. Human convalescents (HCS) and Pfizer/BioNTech vaccinees sera provided comparison panels. ResultsAll three doses of ChulaCov19 were well tolerated and elicited robust dose-dependent and age- dependent B- and T-cell responses. Transient mild/moderate injection site pain, fever, chills, fatigue, and headache were more common after the second dose. Four weeks after the second ChulaCov19: dose at 10, 25, and 50 {micro}g dose, MicroVNT-50 Geometric mean titer (GMT) against wild-type was 848, 736 and 1,140 IU/mL, respectively, versus 267 IU/mL for HCS. All dose levels elicited 100% seroconversion, with GMT ratio 4-8-fold higher than for HCS (p<0.01), and high IFN{gamma} spot-forming cells/million peripheral blood mononuclear cells. The 50 {micro}g dose induced better cross-neutralization against Alpha, Beta, Gamma, and Delta variants than lower doses. ConclusionsChulaCov19 at 50 {micro}g/dose is well tolerated and elicited higher neutralizing antibodies than HCS with strong T-cell responses. These antibodies cross neutralized four variants of concern and ChulaCov19 has therefore proceeded to phase 2 and 3 clinical trials. Trial registration numberClinicalTrials.gov Identifier NCT04566276 Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/22274989v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@3f6e6corg.highwire.dtl.DTLVardef@6aa1b7org.highwire.dtl.DTLVardef@9f0c29org.highwire.dtl.DTLVardef@1d75e38_HPS_FORMAT_FIGEXP M_FIG C_FIG

A randomized clinical trial of a booster dose with low versus standard dose of AZD1222 in adult after 2 doses of inactivated vaccines

BackgroundImmunogenicity of inactivated SARS-CoV-2 vaccine has waning antibody over time. With the emergence of the SARS-CoV-2 delta variant, which requires higher neutralizing antibody to prevent infection, a booster dose is needed. ObjectiveTo evaluate immunogenicity and reactogenicity of standard- versus low-dose ChAdOx1 nCoV-19 vaccine booster after CoronaVac in healthy adults. MethodsA double-blinded, randomized, controlled trial of adult, aged 18-59 years, with completion of 2-dose CoronaVac at 21-28 days apart for more than 2 months was conducted. Participants were randomized to receive AZD1222 (Oxford/AstraZeneca) intramuscularly; standard dose (SD, 5x1010 viral particles) or low dose (LD, 2.5x1010 viral particles). Surrogate virus neutralization test (sVNT) against wild type and delta variant, and anti-spike-receptor-binding-domain IgG (anti-S-RBD IgG) were compared as geometric mean ratio (GMR) at day 14 and 90 between LD and SD arms. ResultsFrom July-August 2021, 422 adults with median age of 44 (IQR 36-51) years were enrolled. The median interval from CoronaVac to AZD1222 booster was 77 (IQR 64-95) days. At baseline, geometric means (GMs) of sVNT against delta variant and anti-S-RBD IgG were 18.1%inhibition (95%CI 16.4-20.0) and 111.5 (105.1-118.3) BAU/ml. GMs of sVNT against delta variant and anti-S-RBD IgG in SD were 95.6%inhibition (95%CI 94.3-97.0) and 1975.1 (1841.7-2118.2) BAU/ml at day 14, and 89.4%inhibition (86.4-92.4) and 938.6 (859.9-1024.4) BAU/ml at day 90, respectively. GMRs of sVNT against delta variant and anti-S-RBD IgG in LD compared to SD were 1.00 (95%CI 0.98-1.02) and 0.84 (0.76-0.93) at day 14, and 0.98 (0.94-1.03) and 0.89 (0.79-1.00) at day 90, respectively. LD recipients had significantly lower rate of fever (6.8%vs25.0%) and myalgia (51.9%vs70.7%) compared to SD. ConclusionHalf-dose AZD1222 booster after 2-dose inactivated SARS-CoV-2 vaccination had non-inferior immunogenicity, yet lower systemic reactogenicity. Fractional low-dose AZD1222 booster should be considered especially in resource-constrained settings. Highlights- Low dose AZD1222 could boost comparable immunity to standard dose in healthy adult who completed 2 doses of inactivated SARS-CoV-2 vaccines. - Less reactogenicity occurred in low-dose AZD1222 booster than standard-dose recipients. Thai Clinical Trials Registry (thaiclinicaltrials.org): TCTR20210722003

Phase 2 Open-Label Study of Long-Term Safety, Tolerability, and Antiviral Activity of Rilpivirine in Antiretroviral-Naive Adolescents Living with HIV-1.

This phase 2 study investigated long-term safety and efficacy of rilpivirine (RPV) plus two investigator-selected nucleos(t)ide reverse transcriptase inhibitors (NRTIs) in HIV-1-infected antiviral therapy-naive adolescents. Participants (≥12 to <18 years of age) were treated with RPV at 25 mg once daily (q.d.) plus 2 NRTIs and entered the treatment extension period for up to 240 weeks, with visits every 3 months. Long-term safety (analysis of adverse events [AEs] and laboratory results), efficacy (virologic response and outcome for patients with viral loads of <50 and <400 by time to loss of virologic response [TLOVR] and FDA Snapshot methods, as well as CD4+ cell count), and adherence (by pill count) for up to 240 weeks are presented. Twenty-four of 36 participants entered the treatment extension period, and 21 completed week 240. At week 240, a viral load of <50 copies/mL was achieved by 14/32 (43.8%) participants; virologic response by TLOVR was higher in participants with a baseline viral load of ≤100,000 copies/mL (48.0%) versus a viral load of >100,000 copies/mL (28.6%). By FDA Snapshot, a viral load of <50 copies/mL at week 240 was found in 53.1% (17/32) of participants with a baseline viral load of ≤100,000 copies/mL. Higher response was observed in participants with adherence of >95% and a baseline viral load of ≤100,000 copies/mL. Through week 240, 16/32 participants (50.0%) experienced virologic failure, including seven who developed treatment-emergent RPV resistance-associated mutations (RAMs [frequently E138K]): all 7 had ≥1 treatment-emergent NRTI RAM. No serious AEs after week 48, no discontinuations due to AEs between week 48 and week 240, and no new safety signals were observed. RPV did not affect pubertal development or adolescent growth. At the 5-year follow-up, efficacy was low in adolescents, particularly those with poor adherence and/or a high baseline viral load of >100,000 copies/mL. To limit the risk of virologic failure, RPV is restricted to patients with a baseline VL of ≤100,000 copies/mL in most countries. In addition, adequate treatment adherence to RPV treatment is imperative for long-term viral suppression and should be emphasized in the management of adolescents living with HIV. RPV exhibited a favorable long-term safety profile for adolescents living with HIV-1 with adequate adherence. (This study has been registered at ClinicalTrials.gov under identifier NCT00799864.).

Immunogenicity and reactogenicity after booster dose with AZD1222 via intradermal route among adult who had received CoronaVac

BackgroundCurrently, booster dose is needed after 2 doses of inactivated COVID-19 vaccine. With limited resource and shortage of COVID-19 vaccine, intradermal(ID) administration might be a potential dose-sparing strategy. ObjectiveTo determine antibody response and reactogenicity of ID ChAdOx1 nCoV-19 vaccine(AZD1222,Oxford/AstraZeneca) as a booster dose after completion of 2-dose CoronaVac(SV) in healthy adult. MethodsThis is a prospective cohort study of adult aged 18-59 years who received 2-dose SV at 14-35 days apart for more than 2 months. Participants received ID AZD1222 at fractional low dose(1x1010 viral particles,0.1ml). Antibody responses were evaluated by surrogate virus neutralization test(sVNT) against wild type and delta variant and anti-spike-receptor-binding-domain immunoglobulin G(anti-S-RBD IgG) at prior, day14 or 28, and day90 post booster. Solicited reactogenicity was collected during 7 days post-booster. Primary endpoint was the differences of sVNT against delta strain [≥]80%inhibition at day14 and 90 compared with the parallel cohort study of 0.5-ml intramuscular(IM) route. ResultsFrom August2021, 100 adults with median(IQR) age of 46(41-52) years participated. At baseline, geometric means(GMs) of sVNT against delta strain prior to booster were 22.4%inhibition(95%CI 18.7-26.9) and of anti-S-RBD IgG were 109.3(95.4-125.1)BAU/ml. GMs of sVNT against delta strain were 92.9%inhibition(95%CI 87.7-98.3) at day14 and 73.1%inhibition(66.7-80.2) at day90 post ID booster. The differences of proportion of participants with sVNT to delta strain[≥]80%inhibition in ID recipients versus IM were +4.2%(95%CI-2.0to10.5) at day14, and -37.3%(-54.2to-20.3) at day90. Anti-S-RBD IgG GMs were 2037.1(95%CI1770.9-2343.2) at day14 and 744.6(650.1-852.9) BAU/ml at day90, respectively. Geometric mean ratios(GMRs) of anti-S-RBD IgG were 0.99(0.83-1.20) at day14, and 0.82(0.66-1.02) at day90. Only 18% reported feverish, compared with 37% of IM(p=0.003). Only 18% reported feverish, compared with 37% of IM(p=0.003). Common reactogenicity was erythema(55%) at injection site while 7% reported blister. ConclusionLow-dose ID AZD1222 booster enhanced lower neutralizing antibodies at 3 months compared with IM route. Less systemic reactogenicity occurred, but higher local reactogenicity. HighlightsO_LIIntradermal AZD1222 booster vaccine gave comparable short-term immunogenicity but lower 90-day immunogenicity with conventional intramuscular vaccine. C_LIO_LILower systemic but higher local reactogenicity was found in intradermal AZD1222 booster vaccine. C_LIO_LIBlister and pruritus could be seen after intradermal AZD1222 booster vaccine. C_LI

Short-Term Immune Response After Inactivated SARS-CoV-2 (CoronaVac, Sinovac) And ChAdOx1 nCoV-19 (Vaxzevria, Oxford-AstraZeneca) Vaccinations in Thai Health Care Workers

BackgroundInactivated SARS-CoV-2 (CoronaVac(R),Sinovac, or SV) and ChAdOx1 nCoV-19 (Vaxzevria(R),Oxford-Astra Zeneca, or AZ) vaccines have been administered to the health care workers (HCWs) in Thailand. ObjectiveTo determine the short-term immune response after the SV and AZ vaccinations in HCWs. MethodsIn this prospective cohort study, HCWs who completed a 2-dose regimen of the SV or AZ were included. Immune response was evaluated by surrogate viral neutralization test (sVNT) and anti-SARS-CoV-2 total antibody. Blood samples were analyzed at 4 and 12 weeks after the complete SV vaccination and at 4 weeks after each dose of the AZ vaccination. The primary outcome was the seroconversion rate at 4-weeks after complete immunization. ResultsOverall, 185 HCWs with a median (IQR) age of 40.5(30.3-55.8) years (94 HCWs in the SV group and 91 in the AZ group) were included. At 4 weeks after completing the SV vaccination, 60.6% (95%CI:50.0-70.6%) had seroconversion evaluated by sVNT([≥]68%inhibition), comparable to the patients recovered from mild COVID-19 infection(69.0%), with a rapid reduction to 12.2%(95%CI:6.3-20.8) at 12 weeks. In contrast, 85.7%(95%CI:76.8-92.2%) HCWs who completed the second dose of the AZ for 4 weeks had seroconversion, comparable to the COVID-19 pneumonia patients(92.5%). When using the anti-SAR-CoV-2 total antibody level([≥]132 U/ml) criteria, only 71.3% HCWs in the SV group had seroconversion, compared to 100% in the AZ group. ConclusionA rapid decline of short-term immune response in the HCWs after the SV vaccination indicates the need for a vaccine booster, particularly during the ongoing spreading of the SAR-CoV-2 variants of concern.

Antibody Responses to SARS-CoV-2 in Coronavirus Diseases 2019 Patients with Different Severity

BackgroundMore understanding of antibody responses in the SARS-CoV-2 infected population is useful for vaccine development. AimTo investigate SARS-CoV-2 IgA and IgG among COVID-19 Thai patients with different severity. MethodsWe used plasma from 118 adult patients who have confirmed SARS-CoV-2 infection and 49 patients under investigation without infection, 20 patients with other respiratory infections, and 102 healthy controls. Anti-SARS-CoV-2 IgA and IgG were performed by enzyme-linked immunosorbent assay from Euroimmun. The optical density ratio cut off for positive test was 1.1 for IgA and 0.8 for IgG. The association of antibody response with the severity of diseases and the day of symptoms was performed. ResultsFrom Mar 10 to May 31, 2020, 289 participants were enrolled, and 384 samples were analyzed. Patients were categorized by clinical manifestations to mild (n = 59), moderate (n = 27) and severe (n = 32). The overall sensitivity of IgA and IgG from samples collected after day 7 is 87.9% (95% CI 79.8-93.6) and 84.8% (95% CI 76.2-91.3), respectively. The severe group had a significantly higher level of specific IgA and IgG to S1 antigen compared to the mild group. All moderate to severe patients have specific IgG while 20% of the mild group did not have any IgG detected after two weeks. Interestingly, SARS-CoV-2 IgG level was significantly higher in males compared to females among the severe group (p = 0.003). ConclusionThe serologic test for SARS-CoV-2 has high sensitivity after the second week after onset of illness. Serological response differs among patients with different severity and different sex.

Clinical Features and Survival Outcomes of Invasive Aspergillosis in Pediatric Patients at a Medical School in Thailand.

BACKGROUND: Invasive aspergillosis (IA) is a severe infection in immunocompromised patients. Recently, serum galactomannan has been widely used for diagnosis and voriconazole as an antifungal agent. The objective of this study is to describe clinical features and survival outcomes of IA. MATERIAL AND METHOD: A retrospective chart review of IA in patients younger than 18 years old at King Chulalongkorn Memorial Hospital, Thailand, was conducted. Clinical definitions were based on criteria oft he European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) 2008. RESULTS: Between January 2006 and December 2012, 40 cases of invasive aspergillosis were identified, classified as proven (8 patients, 20%), probable (28, 70%), and possible IA (4, 10%). Median age of patients was 10 years (range, 42 days-17 years). The most common underlying disease was hematologic malignancy (60%). The major risk factor was neutropenia (65%) with median duration of 21 days (range, 4-58 days). The most common site of infection was in the lungs (80%). The most common computed tomography chest finding was nodules (71%). An air crescent sign was seen only in 11% and a halo sign was found only in 7% of patients. Serum galactomannan was positive in 78% of patients with median value of 1.34 (range 0.5-5.6). Only seven patients (17%) had microbiological confirmation, of which were Aspergillus flavus (4 cases) and Aspergillus fumigates (3 cases). Antifungal therapy included voriconazole (23 patients, 58%), amphotericin B (12, 30%), liposomal amphotericin B (3, 8%), caspofungin (1, 2%) and itraconazole (1, 2%). Two deaths related to angioinvasive complications of aspergillosis (pulmonary hemorrhage and rupture mycotic aneurysm) were reported The 3-month and 12- month survival rates after diagnosed IA were 73.7% and 56.7%, respectively. The major cause of death was new episode of sepsis found in 11 cases (52%). CONCLUSION: The 1-year survival rate was poor; however, cause of death is related to complications of the immunocompromised state not from IA.