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BACKGROUNDThe rising breakthrough infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, especially Omicron and its sub-lineages, have raised an urgent need to develop broad-spectrum vaccines against coronavirus disease 2019 (COVID-19). We have developed a mosaic-type recombinant vaccine candidate, named NVSI-06-09, having immune potentials against a broad range of SARS-CoV-2 variants. METHODSAn ongoing randomized, double-blind, controlled phase 2 trial was conducted to evaluate the safety and immunogenicity of NVSI-06-09 as a booster dose in subjects aged 18 years and older from the United Arab Emirates (UAE), who had completed two or three doses of BBIBP-CorV vaccinations at least 6 months prior to the enrollment. The participants were randomly assigned with 1:1 to receive a booster dose of NVSI-06-09 or BBIBP-CorV. The primary outcomes were immunogenicity and safety against SARS-CoV-2 Omicron variant, and the exploratory outcome was cross-immunogenicity against other circulating strains. RESULTSA total of 516 participants received booster vaccination. Interim results showed a similar safety profile between NVSI-06-09 and BBIBP-CorV booster groups, with low incidence of adverse reactions of grade 1 or 2. For immunogenicity, by day 14 after the booster vaccination, the fold rises in neutralizing antibody geometric mean titers (GMTs) from baseline level elicited by NVSI-06-09 were remarkably higher than those by BBIBP-CorV against the prototype strain (19.67 vs 4.47-fold), Omicron BA.1.1 (42.35 vs 3.78-fold), BA.2 (25.09 vs 2.91-fold), BA.4 (22.42 vs 2.69-fold), and BA.5 variants (27.06 vs 4.73-fold). Similarly, the neutralizing GMTs boosted by NVSI-06-09 against Beta and Delta variants were also 6.60-fold and 7.17-fold higher than those boosted by BBIBP-CorV. CONCLUSIONSA booster dose of NVSI-06-09 was well-tolerated and elicited broad-spectrum neutralizing responses against SARS-CoV-2 prototype strain and immune-evasive variants, including Omicron and its sub-lineages. The immunogenicity of NVSI-06-09 as a booster vaccine was superior to that of BBIBP-CorV. (Funded by LIBP and BIBP of Sinopharm; ClinicalTrials.gov number, NCT05293548).
ABSTRACT
Large-scale populations in the world have been vaccinated with COVID-19 vaccines, however, breakthrough infections of SARS-CoV-2 are still growing rapidly due to the emergence of immune-evasive variants, especially Omicron. It is urgent to develop effective broad-spectrum vaccines to better control the pandemic of these variants. Here, we present a mosaic-type trimeric form of spike receptor-binding domain (mos-tri-RBD) as a broad-spectrum vaccine candidate, which carries the key mutations from Omicron and other circulating variants. Tests in rats showed that the designed mos-tri-RBD, whether used alone or as a booster shot, elicited potent cross-neutralizing antibodies against not only Omicron but also other immune-evasive variants. Neutralizing antibody titers induced by mos-tri-RBD were substantially higher than those elicited by homo-tri-RBD (containing homologous RBDs from prototype strain) or the inactivated vaccine BBIBP-CorV. Our study indicates that mos-tri-RBD is highly immunogenic, which may serve as a broad-spectrum vaccine candidate in combating SARS-CoV-2 variants including Omicron.
ABSTRACT
The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 is an attractive target for COVID-19 vaccine developments, which naturally exists in a trimeric form. Here, guided by structural and computational analyses, we present a mutation-integrated trimeric form of RBD (mutI tri-RBD) as a broadly protective vaccine candidate, in which three RBDs were individually grafted from three different circulating SARS-CoV-2 strains including the prototype, Beta (B.1.351) and Kappa (B.1.617). The three RBDs were then connected end-to-end and co-assembled to possibly mimic the native trimeric arrangements in the natural S protein trimer. The recombinant expression of the mutI tri-RBD, as well as the homo-tri-RBD where the three RBDs were all truncated from the prototype strain, by mammalian cell exhibited correct folding, strong bio-activities, and high stability. The immunization of both the mutI tri-RBD and homo-tri-RBD plus aluminum adjuvant induced high levels of specific IgG and neutralizing antibodies against the SARS-CoV-2 prototype strain in mice. Notably, regarding to the "immune-escape" Beta (B.1.351) variant, mutI tri-RBD elicited significantly higher neutralizing antibody titers than homo-tri-RBD. Furthermore, due to harboring the immune-resistant mutations as well as the evolutionarily convergent hotspots, the designed mutI tri-RBD also induced strong broadly neutralizing activities against various SARS-CoV-2 variants, especially the variants partially resistant to homo-tri-RBD. Homo-tri-RBD has been approved by the China National Medical Products Administration to enter clinical trial (No. NCT04869592), and the superior broad neutralization performances against SARS-CoV-2 support the mutI tri-RBD as a more promising vaccine candidate for further clinical developments.
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@#AIM: To explore the safety and efficacy of air tamponade in the closure of large idiopathic macular holes(IMHs).<p>METHODS: A retrospective study. Nine eyes of eight patients with large IMH were admitted to our hospital from June 2017 to may 2018. Mean macular hole(MH)minimum diameter >700 μm and mean MH basal diameter >1 300 μm. All the patients were underwent 25G phacovitrectomy, internal limiting membrane flaptuck, and sterilized air tamponade in the vitreous cavity. With a mean follow up of 12mo, the best-corrected visual acuity(BCVA)and macular hole closure were compared before and after operation.<p>RESULTS: At the last follow up, all the patients obtained MH closure. The SD-OCT showed that the postoperative MH closure rate was 100%(9/9). Postoperative BCVA improved significantly compared with the preoperative(0.83±0.26 <i>vs</i> 1.27±0.28), the difference was statistically significant(<i>P</i>=0.007). No complications occurred during and after the operation.<p>CONCLUSION: Sterilized air tamponade might provide a safe and efficient effect on the closure of large IMHs.
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OBJECTIVE@#The objective of this study is to determine whether coronary atherosclerotic plaque composition is associated with cardiovascular disease (CVD) risk in Chinese adults.@*METHODS@#We performed a cross-sectional analysis in 549 subjects without previous diagnosis or clinical symptoms of CVD in a community cohort of middle-aged Chinese adults. The participants underwent coronary computed tomography (CT) angiography for the evaluation of the presence and composition of coronary plaques. CVD risk was evaluated by the Framingham risk score (FRS) and the 10-year atherosclerotic cardiovascular disease (ASCVD) risk score.@*RESULTS@#Among the 549 participants, 267 (48.6%) had no coronary plaques, 201 (36.6%) had noncalcified coronary plaques, and 81 (14.8%) had calcified or mixed coronary plaques. The measures of CVD risk including FRS and ASCVD risk score and the likelihood of having elevated FRS significantly increased across the groups of participants without coronary plaques, with noncalcified coronary plaques, and with calcified or mixed coronary plaques. However, only calcified or mixed coronary plaques were significantly associated with an elevated ASCVD risk score [odds ratio (OR) 2.41; 95% confidence interval (CI) 1.09-5.32] compared with no coronary plaques, whereas no significant association was found for noncalcified coronary plaques and elevated ASCVD risk score (OR 1.25; 95% CI 0.71-2.21) after multivariable adjustment.@*CONCLUSION@#Calcified or mixed coronary plaques might be more associated with an elevated likelihood of having CVD than noncalcified coronary plaques.
