COVID-19 vaccine development: milestones, lessons and prospects

Comprehensive insights into COVID-19 vaccine-associated multiple evanescent white dot syndrome (MEWDS): A systematic analysis of reported cases

Considering the widespread use of COVID-19 vaccines as a preventive measure against the spread of the virus, it's necessary to direct attention to the adverse effects associated with vaccines in a limited group of populations. Multiple evanescent white dot syndrome (MEWDS) following COVID-19 vaccination is a rare adverse reaction associated with COVID-19 vaccines. In this systematic review, we collected 19 articles with 27 patients up to November 1, 2023, summarizing the basic information, clinical manifestations, examinations, treatments, and recoveries of the 27 patients. The 27 enrolled patients (6 males, 21 females) had a median age of 34.1 years (15-71 years old) and were mainly from 5 regions: Asia (8), the Mediterranean region (8), North America (7), Oceania (3) and Brazil (1). Symptoms occurred post-first dose in 9 patients, post-second dose in 14 (1 with symptoms after both), post-third dose in 1, and both post-second and booster doses in 1, while details on 2 cases were not disclosed. Treatments included tapered oral steroids (6), topical steroids (3), tapered prednisone with antiviral drugs and vitamins (1), and valacyclovir and acetazolamide (1), while 16 received no treatment. All patients experienced symptom improvement, and nearly all patients ultimately recovered. Moreover, we summarized possible hypotheses concerning the mechanism of COVID-19 vaccine-associated MEWDS. The findings provide insights into the clinical aspects of COVID-19 vaccine-associated MEWDS. More attention should be given to patients with vaccine-associated MEWDS, and necessary treatment should be provided to patients experiencing a substantial decline in visual acuity to improve their quality of life.

Impact of COVID-19 vaccination status on hospitalization and disease severity: A descriptive study in Nagasaki Prefecture, Japan

Coronavirus disease 2019 (COVID-19) was extraordinarily harmful, with high rates of infection and hospitalization. This study aimed to evaluate the impact of COVID-19 vaccination status and other factors on hospitalization and disease severity, using data from Nagasaki Prefecture, Japan. Confirmed cases of COVID-19 infection with vaccination status were included and the differences in characteristics between different vaccination statuses, hospitalization or not, and patients with varying levels of disease severity were analyzed. Furthermore, logistic regression was used to calculate odds ratio (ORs) and 95% confidence intervals (CI) to evaluate the association of various factors with hospitalization and disease severity. From March 14, 2020 to August 31, 2022, 23,139 patients were unvaccinated 13,668 vaccinated the primary program with one or two doses, and 4,575 completed the booster. Vaccination reduced the risk of hospitalization with an odd ratio of 0.759 (95% CI: 0.654-0.881) and the protective effect of completed booster vaccination was more pronounced (OR: 0.261, 95% CI: 0.207-0.328). Similarly, vaccination significantly reduced the risk of disease severity (vaccinated primary program: OR: 0.191, 95% CI: 0.160-0.228; completed booster vaccination: OR: 0.129, 95% CI: 0.099-0.169). Overall, unvaccinated, male, elderly, immunocompromised, obese, and patients with other severe illness factors were all risk factors for COVID-19-related hospitalization and disease severity. Vaccination was associated with a decreased risk of hospitalization and disease severity, and highlighted the benefits of completing booster.

Gene therapy in preeclampsia: the dawn of a new era

Preeclampsia is a severe complication of pregnancy, affecting an estimated 4 million women annually. It is one of the leading causes of maternal and fetal mortality worldwide, and it has life-long consequences. The maternal multisystemic symptoms are driven by poor placentation, which causes syncytiotrophoblastic stress and the release of factors into the maternal bloodstream. Amongst them, the soluble fms-like tyrosine kinase-1 (sFLT-1) triggers extensive endothelial dysfunction by acting as a decoy receptor for the vascular endothelial growth factor (VEGF) and the placental growth factor (PGF). Current interventions aim to mitigate hypertension and seizures, but the only definite treatment remains induced delivery. Thus, there is a pressing need for novel therapies to remedy this situation. Notably, CBP-4888, a siRNA drug delivered subcutaneously to knock down sFLT1 expression in the placenta, has recently obtained Fast Track approval from the Food and Drug Administration (FDA) and is undergoing a phase 1 clinical trial. Such advance highlights a growing interest and significant potential in gene therapy to manage preeclampsia. This review summarizes the advances and prospects of gene therapy in treating placental dysfunction and illustrates crucial challenges and considerations for these emerging treatments.

Pharmacological effect of cepharanthine on SARS-CoV-2-induced disease in a Syrian hamster model

BACKGROUND

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health threat. Although several effective vaccines and therapeutics have been developed, continuous emergence of new variants necessitates development of drugs with different mechanisms of action. Recent studies indicate that cepharanthine, a chemical derivative purified from Stephania cepharantha, inhibits SARS-CoV-2 replication in vitro.

METHODS

This study examined the in vivo effects of cepharanthine using a Syrian hamster SARS-CoV-2 infection model. To evaluate the prophylactic and therapeutic effects, cepharanthine was intranasally administered before or after SARS-CoV-2 infection. Effects were assessed by monitoring body weight changes, lung pathology, lung viral load, and inflammatory response in the lungs.

RESULTS

Pre-infection administration of cepharanthine resulted in less weight loss, reduced virus titers, alleviated histopathological severity, and decreased lung inflammation. Furthermore, post-infection administration of cepharanthine also exhibited therapeutic effects.

CONCLUSIONS

This study demonstrated that both prophylactic and therapeutic administration of cepharanthine reduces the pathogenesis of COVID-19 in a Syrian hamster SARS-CoV-2 infection model. Our findings suggest that cepharanthine is a potential therapeutic agent against COVID-19.

Unravelling the complex interplay of age, comorbidities, and multimorbidities in COVID-19 disease progression: Clinical implications and future perspectives

Introduction

The COVID-19 infection as an inflammatory disease has posed significant challenges to global public health due to multi-factor risks associated with it leading to disease severity and mortality. Understanding the effect of age and comorbidities on overall disease progression is crucial to identify highly susceptible individuals and to develop effective disease management strategies in a resource limited country like Pakistan.

Methodology

A retrospective study was conducted on hospitalized COVID-19 patients to assess the prevalence of various comorbidities among different age groups and their effect on disease severity and mortality rate.

Results

In this retrospective study, a cohort of 618 hospitalized COVID-19 patients was analyzed, consisting of 387 males (62.6 %) and 231 females (37.4 %). Notably, the young age group (15-24 years), had the lowest frequency of hospitalized COVID-19 patients, while no case was observed in children (≤14 years) showing a significant association (p < 0.001) of age and disease prevalence. Comorbidities were observed in 63.9 % of COVID-19 patients including hypertension (HTN), diabetes mellitus (DM), ischemic heart diseases (IHD), asthma, chronic kidney disease (CKD) and tuberculosis (TB). The most common comorbidities were HTN (42.1 %) followed by DM (33.8 %), IHD (16.5 %), asthma (11.2 %), CKD (7.9 %) and TB (1.9 %).Furthermore, the study revealed a significant association between comorbidities, age groups, and the need for non-invasive ventilation (NIV) (p < 0.001), mechanical ventilation (MV) (p < 0.001), and intensive care unit (ICU) admission (p < 0.001). Patients with specific comorbidities and those in the older age group (≥65 years) demonstrated a higher need for these interventions. However, patients without any comorbidity consistently exhibited the highest cumulative proportion of survival at each time point, indicating better overall survival outcomes. In contrast, patients with multimorbidities of DM/HTN/IHD, HTN/IHD, and DM/HTN/CKD had comparatively lower survival rates and higher mortality rates (p < 0.001).

Conclusion

This research highlights the significant impact of age, comorbidities and multimorbidities on the severity and mortality of COVID-19 patients. It highlights the importance of considering these factors in tailoring effective management strategies for patients with COVID-19 or other infectious respiratory diseases.

Natural and socio-environmental factors in the transmission of COVID-19: a comprehensive analysis of epidemiology and mechanisms

PURPOSE OF REVIEW

There are significant differences in the transmission rate and mortality rate of COVID-19 under environmental conditions such as seasons and climates. However, the impact of environmental factors on the role of the COVID-19 pandemic and the transmission mechanism of the SARS-CoV-2 is unclear. Therefore, a comprehensive understanding of the impact of environmental factors on COVID-19 can provide innovative insights for global epidemic prevention and control policies and COVID-19 related research. This review summarizes the evidence of the impact of different natural and social environmental factors on the transmission of COVID-19 through a comprehensive analysis of epidemiology and mechanism research. This will provide innovative inspiration for global epidemic prevention and control policies and provide reference for similar infectious diseases that may emerge in the future.

RECENT FINDINGS

Evidence reveals mechanisms by which natural environmental factors influence the transmission of COVID-19, including (i) virus survival and transport, (ii) immune system damage, (iii) inflammation, oxidative stress, and cell death, and (iiii) increasing risk of complications. All of these measures appear to be effective in controlling the spread or mortality of COVID-19: (1) reducing air pollution levels, (2) rational use of ozone disinfection and medical ozone therapy, (3) rational exposure to sunlight, (4) scientific ventilation and maintenance of indoor temperature and humidity, (5) control of population density, and (6) control of population movement. Our review indicates that with the continuous mutation of SARS-CoV-2, high temperature, high humidity, low air pollution levels, and low population density more likely to slow down the spread of the virus.

Efficacy, immunogenicity and safety of CoronaVac® in children and adolescents aged 6 months to 17 years: a multicenter, randomized, double-blind, placebo-controlled phase III clinical trial

Safe and effective vaccines against COVID-19 for children and adolescents are needed. This international multicenter, randomized, double-blind, placebo-controlled, phase III clinical trial assessed the efficacy, immunogenicity, and safety of CoronaVac® in children and adolescents (NCT04992260). The study was carried out in Chile, South Africa, Malaysia, and the Philippines. The enrollment ran from September 10, 2021 to March 25, 2022. For efficacy assessment, the median follow-up duration from 14 days after the second dose was 169 days. A total of 11,349 subjects were enrolled. Two 3-μg injections of CoronaVac® or placebo were given 28 days apart. The primary endpoint was the efficacy of the CoronaVac®. The secondary endpoints were the immunogenicity and safety. The vaccine efficacy was 21.02% (95% CI: 1.65, 36.67). The level of neutralizing antibody in the vaccine group was significantly higher than that in the placebo group (GMT: 390.80 vs. 62.20, P <0.0001). Most adverse reactions were mild or moderate. All the severe adverse events were determined to be unrelated to the investigational products. In conclusion, in the Omicron-dominate period, a two-dose schedule of 3 μg CoronaVac® was found to be safe and immunogenic, and showed potential against symptomatic COVID-19 in healthy children and adolescents.

Advances in the design and delivery of RNA vaccines for infectious diseases

RNA medicines represent a paradigm shift in treatment and prevention of critical diseases of global significance, e.g., infectious diseases. The highly successful messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were developed at record speed during the coronavirus disease 2019 pandemic. A consequence of this is exceptionally shortened vaccine development times, which in combination with adaptability makes the RNA vaccine technology highly attractive against infectious diseases and for pandemic preparedness. Here, we review state of the art in the design and delivery of RNA vaccines for infectious diseases based on different RNA modalities, including linear mRNA, self-amplifying RNA, trans-amplifying RNA, and circular RNA. We provide an overview of the clinical pipeline of RNA vaccines for infectious diseases, and present analytical procedures, which are paramount for characterizing quality attributes and guaranteeing their quality, and we discuss future perspectives for using RNA vaccines to combat pathogens beyond SARS-CoV-2.

Virus-like structures for combination antigen protein mRNA vaccination

Improved vaccination requires better delivery of antigens and activation of the natural immune response. Here we report a lipid nanoparticle system with the capacity to carry antigens, including mRNA and proteins, which is formed into a virus-like structure by surface decoration with spike proteins, demonstrating application against SARS-CoV-2 variants. The strategy uses S1 protein from Omicron BA.1 on the surface to deliver mRNA of S1 protein from XBB.1. The virus-like particle enables specific augmentation of mRNAs expressed in human respiratory epithelial cells and macrophages via the interaction the surface S1 protein with ACE2 or DC-SIGN receptors. Activation of macrophages and dendritic cells is demonstrated by the same receptor binding. The combination of protein and mRNA increases the antibody response in BALB/c mice compared with mRNA and protein vaccines alone. Our exploration of the mechanism of this robust immunity suggests it might involve cross-presentation to diverse subsets of dendritic cells ranging from activated innate immune signals to adaptive immune signals.

Current development of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies (Review)

The coronavirus disease 2019 pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) seriously affected global public health security. Studies on vaccines, neutralizing antibodies (NAbs) and small molecule antiviral drugs are currently ongoing. In particular, NAbs have emerged as promising therapeutic agents due to their well‑defined mechanism, high specificity, superior safety profile, ease of large‑scale production and simultaneous application for both prevention and treatment of viral infection. Numerous NAb therapeutics have entered the clinical research stages, demonstrating promising therapeutic and preventive effects. These agents have been used for outbreak prevention and control under urgent authorization processes. The present review summarizes the molecular targets of SARS‑CoV‑2‑associated NAbs and screening and identification techniques for NAb development. Moreover, the current shortcomings and challenges that persist with the use of NAbs are discussed. The aim of the present review is to offer a reference for the development of NAbs for any future emergent infectious diseases, including SARS‑CoV‑2.

One-pot Golden Gate Assembly of an avian infectious bronchitis virus reverse genetics system

Avian infectious bronchitis is an acute respiratory disease of poultry of particular concern for global food security. Investigation of infectious bronchitis virus (IBV), the causative agent of avian infectious bronchitis, via reverse genetics enables deeper understanding of virus biology and a rapid response to emerging variants. Classic methods of reverse genetics for IBV can be time consuming, rely on recombination for the introduction of mutations, and, depending on the system, can be subject to genome instability and unreliable success rates. In this study, we have applied data-optimized Golden Gate Assembly design to create a rapidly executable, flexible, and faithful reverse genetics system for IBV. The IBV genome was divided into 12 fragments at high-fidelity fusion site breakpoints. All fragments were synthetically produced and propagated in E. coli plasmids, amenable to standard molecular biology techniques for DNA manipulation. The assembly can be carried out in a single reaction, with the products used directly in subsequent viral rescue steps. We demonstrate the use of this system for generation of point mutants and gene replacements. This Golden Gate Assembly-based reverse genetics system will enable rapid response to emerging variants of IBV, particularly important to vaccine development for controlling spread within poultry populations.

Kupffer cells determine intrahepatic traffic of PEGylated liposomal doxorubicin

Intrahepatic accumulation dominates organ distribution for most nanomedicines. However, obscure intrahepatic fate largely hampers regulation on their in vivo performance. Herein, PEGylated liposomal doxorubicin is exploited to clarify the intrahepatic fate of both liposomes and the payload in male mice. Kupffer cells initiate and dominate intrahepatic capture of liposomal doxorubicin, following to deliver released doxorubicin to hepatocytes with zonated distribution along the lobule porto-central axis. Increasing Kupffer cells capture promotes doxorubicin accumulation in hepatocytes, revealing the Kupffer cells capture-payload release-hepatocytes accumulation scheme. In contrast, free doxorubicin is overlooked by Kupffer cells, instead quickly distributing into hepatocytes by directly crossing fenestrated liver sinusoid endothelium. Compared to free doxorubicin, liposomal doxorubicin exhibits sustained metabolism/excretion due to the extra capture-release process. This work unveils the pivotal role of Kupffer cells in intrahepatic traffic of PEGylated liposomal therapeutics, and quantitively describes the intrahepatic transport/distribution/elimination process, providing crucial information for guiding further development of nanomedicines.

Synthesis of Structural ADP-Ribose Analogues as Inhibitors for SARS-CoV-2 Macrodomain 1

Protein adenosine diphosphate (ADP)-ribosylation is crucial for a proper immune response. Accordingly, viruses have evolved ADP-ribosyl hydrolases to remove these modifications, a prominent example being the SARS-CoV-2 NSP3 macrodomain, "Mac1". Consequently, inhibitors are developed by testing large libraries of small molecule candidates, with considerable success. However, a relatively underexplored angle in design pertains to the synthesis of structural substrate mimics. Here, we present the synthesis and biophysical activity of novel adenosine diphosphate ribose (ADPr) analogues as SARS-CoV-2 NSP3 Mac1 inhibitors.

A Nanoparticle Vaccine Displaying Conserved Epitopes of the Preexisting Neutralizing Antibody Confers Broad Protection against SARS-CoV-2 Variants

The rapid development of the SARS-CoV-2 vaccine has been used to prevent the spread of coronavirus 2019 (COVID-19). However, the ongoing and future pandemics caused by SARS-CoV-2 variants and mutations underscore the need for effective vaccines that provide broad-spectrum protection. Here, we developed a nanoparticle vaccine with broad protection against divergent SARS-CoV-2 variants. The corresponding conserved epitopes of the preexisting neutralizing (CePn) antibody were presented on a self-assembling Helicobacter pylori ferritin to generate the CePnF nanoparticle. Intranasal immunization of mice with CePnF nanoparticles induced robust humoral, cellular, and mucosal immune responses and a long-lasting immunity. The CePnF-induced antibodies exhibited cross-reactivity and neutralizing activity against different coronaviruses (CoVs). CePnF vaccination significantly inhibited the replication and pathology of SARS-CoV-2 Delta, WIV04, and Omicron strains in hACE2 transgenic mice and, thus, conferred broad protection against these SARS-CoV-2 variants. Our constructed nanovaccine targeting the conserved epitopes of the preexisting neutralizing antibodies can serve as a promising candidate for a universal SARS-CoV-2 vaccine.

SARS-CoV-2 parental vaccination and risk of multisystem inflammatory syndrome in children: a single-center retrospective study

Purpose

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) usually causes a mild disease in children and the most serious consequence is multisystem inflammatory syndrome in children (MIS-C). Currently, there are no data about the protective role of vaccination performed by parents on children regarding the development of MIS-C. The aim of our study is to establish whether parental vaccination is related to MIS-C and the protective value of SARS-CoV-2 vaccination performed by parents against the occurrence of MIS-C in their children.

Materials and Methods

Our retrospective single center study included 124 patients aged 1 month to 18 years admitted to emergency department from April 2020 to March 2022 for coronavirus disease 2019 disease.

Results

Parental vaccination was negatively correlated with the development of MIS-C: 4% of patients with both parents vaccinated developed MIS-C, while patients with no parent vaccinated to have developed MIS-C were 20%.

Conclusion

Parental vaccination could be an important factor influencing the course of the disease and reduces the probability that a child would develop MIS-C by 83% if both parents vaccinated.

Assessment of the neutralizing antibody response in Omicron breakthrough cases in healthcare workers who received the homologous booster of Moderna mRNA-1273

Vaccines against SARS-CoV-2 were developed during the pandemic including the BNT162b2 and the mRNA-1273. We evaluated the levels of binding antibodies against the receptor binding domain and the levels of NAbs in individuals who developed a breakthrough infection after having received three doses of mRNA-1273. A total of 51 participants were included. The breakthrough group was compared to a 1:1 matched-control group. Among the 51 individuals, 18 (35%) developed a breakthrough infection. The GMT of NAbs against the BA.1 in the BK population was 278.1 (95%CI: 168.1-324.1). This titer was significantly lower compared to the matched-control group when considering all data (GMT = 477.4; 95%CI: 316.2-541.0; p = 0.0057). Results were similar for the BA.5 (GMT = 152.0 (95%CI: 76.9-172.9) for breakthrough and 262.0 (95%CI: 171.3-301.8) for control (p = 0.0043)). Our study found that individuals receiving the mRNA-1273 booster and who developed a breakthrough infection presented lower levels of binding antibodies and NAbs before the infection as compared to a matched-control group.

Trichinella spiralis Infection Inhibits the Efficacy of RBD Protein of SARS-CoV-2 Vaccination via Regulating Humoral and Cellular Immunity

Vaccines are the most effective and feasible way to control pathogen infection. Helminths have been reported to jeopardize the protective immunity mounted by several vaccines. However, there are no experimental data about the effect of helminth infection on the effectiveness of COVID-19 vaccines. Here, a mouse model of trichinosis, a common zoonotic disease worldwide, was used to investigate effects of Trichinella spiralis infection on the RBD protein vaccine of SARS-CoV-2 and the related immunological mechanism, as well as the impact of albendazole (ALB) deworming on the inhibitory effect of the parasite on the vaccination. The results indicated that both the enteric and muscular stages of T. spiralis infection inhibited the vaccine efficacy, evidenced by decreased levels of IgG, IgM, sIgA, and reduced serum neutralizing antibodies, along with suppressed splenic germinal center (GC) B cells in the vaccinated mice. Pre-exposure to trichinosis promoted Th2 and/or Treg immune responses in the immunized mice. Furthermore, ALB treatment could partially reverse the inhibitory effect of T. spiralis infection on the efficiency of the vaccination, accompanied by a restored proportion of splenic GC B cells. Therefore, given the widespread prevalence of helminth infections worldwide, deworming therapy needs to be considered when implementing COVID-19 vaccination strategies.

Efficacy and effectiveness of COVID-19 vaccines in Africa: A systematic review

BACKGROUND

Data on COVID-19 vaccine effectiveness to support regional vaccine policy and practice are limited in Africa. Thus, this review aimed to evaluate the efficacy and effectiveness of COVID-19 vaccines administered in Africa.

METHODS

We systematically searched peer-reviewed randomized controlled trials (RCTs), prospective and retrospective cohort studies, and case-control studies that reported on VE in Africa. We carried out a risk of bias assessment, and the findings of this review were synthesized and presented in a narrative form, including tables and figures. The synthesis was focused on COVID-19 VE against various levels of the disease condition and outcomes (infection, hospitalization or critical, and death), time points, and variants of concern.

RESULTS

A total of 13 studies, with a total sample size of 913,285 participants, were included in this review. The majority (8/13) of studies were from South Africa and 38.5% (5/13) were randomized clinical trials. The studies reported that a full dose of Pfizer-BioNTech vaccine had a VE of 100% against COVID-19 infection by Beta (B.1.351) and Delta variants and 96.7% against hospitalization by Delta variant. The Johnson and Johnson vaccine had VE ranging from 38.1%-62.0% against hospitalization and 51.9%- 86% against critical disease by Beta (B 1.351) variant. The Oxford-AstraZeneca vaccine had a VE of 89.4% against hospitalization by the Omicron variant but was not effective against the B.1.351 variant (10.4%). The Sinopharm vaccine had a VE of 67% against infection and 46% against hospitalization by Delta variant.

CONCLUSIONS

COVID-19 vaccines administered in Africa were effective in preventing infections, hospitalization, and death. These review findings underscore the need for concerted efforts of all stakeholders to enhance the access and availability of COVID-19 vaccines and reinforce public awareness to reach the high-risk, unvaccinated group of the African population.

Combined prevention and treatment measures are essential to control nosocomial infections during the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus-2 is a highly contagious positive-sense, single-stranded RNA virus that has rapidly spread worldwide. As of December 17, 2023, 772838745 confirmed cases including 6988679 deaths have been reported globally. This virus primarily spreads through droplets, airborne transmission, and direct contact. Hospitals harbor a substantial number of confirmed coronavirus disease 2019 (COVID-19) patients and asymptomatic carriers, accompanied by high population density and a larger susceptible population. These factors serve as potential triggers for nosocomial infections, posing a threat during the COVID-19 pandemic. Nosocomial infections occur to varying degrees across different countries worldwide, emphasizing the urgent need for a practical approach to prevent and control the intra-hospital spread of COVID-19. This study primarily concentrated on a novel strategy combining preventive measures with treatment for combating COVID-19 nosocomial infections. It suggests preventive methods, such as vaccination, disinfection, and training of heathcare personnel to curb viral infections. Additionally, it explored therapeutic strategies targeting cellular inflammatory factors and certain new medications for COVID-19 patients. These methods hold promise in rapidly and effectively preventing and controlling nosocomial infections during the COVID-19 pandemic and provide a reliable reference for adopting preventive measures in the future pandemic.

Development of Robust Freeze-Drying Process for Long-Term Stability of rVSV-SARS-CoV-2 Vaccine

The thermostability of vaccines, particularly enveloped viral vectored vaccines, remains a challenge to their delivery wherever needed. The freeze-drying of viral vectored vaccines is a promising approach but remains challenging due to the water removal process from the outer and inner parts of the virus. In the case of enveloped viruses, freeze-drying induces increased stress on the envelope, which often leads to the inactivation of the virus. In this study, we designed a method to freeze-dry a recombinant vesicular stomatitis virus (VSV) expressing the SARS-CoV-2 spike glycoprotein. Since the envelope of VSV is composed of 50% lipids and 50% protein, the formulation study focused on both the protein and lipid portions of the vector. Formulations were prepared primarily using sucrose, trehalose, and sorbitol as cryoprotectants; mannitol as a lyoprotectant; and histidine as a buffer. Initially, the infectivity of rVSV-SARS-CoV-2 and the cake stability were investigated at different final moisture content levels. High recovery of the infectious viral titer (~0.5 to 1 log loss) was found at 3-6% moisture content, with no deterioration in the freeze-dried cakes. To further minimize infectious viral titer loss, the composition and concentration of the excipients were studied. An increase from 5 to 10% in both the cryoprotectants and lyoprotectant, together with the addition of 0.5% gelatin, resulted in the improved recovery of the infectious virus titer and stable cake formation. Moreover, the secondary drying temperature of the freeze-drying process showed a significant impact on the infectivity of rVSV-SARS-CoV-2. The infectivity of the vector declined drastically when the temperature was raised above 20 °C. Throughout a long-term stability study, formulations containing 10% sugar (sucrose/trehalose), 10% mannitol, 0.5% gelatin, and 10 mM histidine showed satisfactory stability for six months at 2-8 °C. The development of this freeze-drying process and the optimized formulation minimize the need for a costly cold chain distribution system.

Omicron neutralization character in patients with breast cancer and liver cancer after the nationwide omicron outbreak

BACKGROUND

The surge in omicron variants has caused nationwide breakthrough infections in mainland China since the December 2022. In this study, we report the neutralization profiles of serum samples from the patients with breast cancer and the patients with liver cancer who had contracted subvariant breakthrough infections.

METHODS

In this real-world study, we enrolled 143 COVID-19-vaccinated (81 and 62 patients with breast and liver cancers) and 105 unvaccinated patients with cancer (58 and 47 patients with breast and liver cancers) after omicron infection. Anti-spike receptor binding domain (RBD) IgGs and 50% pseudovirus neutralization titer (pVNT50) for the preceding (wild type), circulating omicron (BA.4-BA.5, and BF.7), and new subvariants (XBB.1.5) were comprehensively analyzed.

RESULTS

Patients with liver cancer receiving booster doses had higher levels of anti-spike RBD IgG against circulating omicron (BA.4-BA.5, and BF.7) and a novel subvariant (XBB.1.5) compared to patients with breast cancer after breakthrough infection. Additionally, all vaccinated patients produced higher neutralizing antibody titers against circulating omicron (BA.4-BA.5, and BF.7) compared to unvaccinated patients. However, the unvaccinated patients produced higher neutralizing antibody against XBB.1.5 than vaccinated patients after Omicron infection, with this trend being more pronounced in breast cancer than in liver cancer patients. Moreover, we found that there was no correlation between anti-spike RBD IgG against wildtype virus and the neutralizing antibody titer, but a positive correlation between anti-spike RBD IgG and the neutralizing antibody against XBB.1.5 was found in unvaccinated patients.

CONCLUSION

Our study found that there may be differences in vaccine response and protective effect against COVID-19 infection in patients with liver and breast cancer. Therefore, we recommend that COVID-19 vaccine strategies should be optimized based on vaccine components and immunology profiles of different patients with cancer.

Safety of an inactivated COVID-19 vaccine (CoronaVac) in children aged 7-14 years in Taizhou, China

Our study aimed to evaluate the safety of CoronaVac, an inactivated vaccine made by Sinovac, in children aged 7-14. We conducted a parent-administered online survey to monitor adverse reactions after vaccinating children in Taizhou, China, from February 15, 2021, to January 19, 2022. 767 parents completed the survey after receiving a questionnaire via WeChat. Overall, 15.3 % (117/767) of children experienced adverse effects after the first dose, and 12.2 % (88/724) after the second. Muscle pain was the most common adverse reaction post-first dose (10.0 %), while localized pain or itching at the injection site was most common after the second dose (7.6 %). In conclusion, the vaccine has a low incidence of side effects. The mild to moderate, transient, and common nature of these effects further boosts parents' confidence in vaccinating their children.

A novel nanobody broadly neutralizes SARS-CoV-2 via induction of spike trimer dimers conformation

The ongoing mutations of the SARS-CoV-2 pose serious challenges to the efficacy of the available antiviral drugs, and new drugs with fantastic efficacy are always deserved investigation. Here, a nanobody called IBT-CoV144 is reported, which exhibits broad neutralizing activity against SARS-CoV-2 by inducing the conformation of spike trimer dimers. IBT-CoV144 was isolated from an immunized alpaca using the RBD of wild-type SARS-CoV-2, and it showed strong cross-reactive binding and neutralizing potency against diverse SARS-CoV-2 variants, including Omicron subvariants. Moreover, the prophylactically and therapeutically intranasal administration of IBT-CoV144 confers fantastic protective efficacy against the challenge of Omicron BA.1 variant in BALB/c mice model. The structure analysis of the complex between spike (S) protein, conducted using Cryo-EM, revealed a special conformation known as the trimer dimers. This conformation is formed by two trimers, with six RBDs in the "up" state and bound by six VHHs. IBT-CoV144 binds to the lateral region of the RBD on the S protein, facilitating the aggregation of S proteins. This aggregation results in steric hindrance, which disrupts the recognition of the virus by ACE2 on host cells. The discovery of IBT-CoV144 will provide valuable insights for the development of advanced therapeutics and the design of next-generation vaccines.

Neonatal and infant infection with SARS-CoV-2

Despite the substantial body of investigative work describing the Coronavirus Disease 2019 (COVID-19) pandemic, its impact on neonates and infants remains less well characterized. Here, we review the data on epidemiology of COVID-19 in this population. Widespread use of universal testing for SARS-CoV-2 among pregnant persons presenting for delivery complicates interpretation of the risks of perinatal exposure. While many neonates and infants with COVID-19 are well-appearing or have only mild signs of illness, factors such as preterm birth, low birth weight, and medical comorbidities increase the risk of severe infection. We highlight potential protective maternal factors, summarize treatment options and discuss vaccine development. Higher quality data are needed to better inform our understanding of COVID-19 in neonates and infants.

Effect and mechanism of quercetin or quercetin-containing formulas against COVID-19: From bench to bedside

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global coronavirus disease 2019 (COVID-19) pandemic since 2019. Immunopathogenesis and thromboembolic events are central to its pathogenesis. Quercetin exhibits several beneficial activities against COVID-19, including antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antithrombotic effects. Although several reviews have been published, these reviews are incomplete from the viewpoint of translational medicine. The authors comprehensively evaluated the evidence of quercetin against COVID-19, both basically and clinically, to apply quercetin and/or its derivatives in the future. The authors searched the PubMed, Embase, and the Cochrane Library databases without any restrictions. The search terms included COVID-19, SARS-CoV-2, quercetin, antiviral, anti-inflammatory, immunomodulatory, thrombosis, embolism, oxidative, and microbiota. The references of relevant articles were also reviewed. All authors independently screened and reviewed the quality of each included manuscript. The Cochrane Risk of Bias Tool, version 2 (RoB 2) was used to assess the quality of the included randomized controlled trials (RCTs). All selected studies were discussed monthly. The effectiveness of quercetin against COVID-19 is not solid due to methodological flaws in the clinical trials. High-quality studies are also required for quercetin-containing traditional Chinese medicines. The low bioavailability and highly variable pharmacokinetics of quercetin hinder its clinical applications. Its positive impact on immunomodulation through reverting dysbiosis of gut microbiota still lacks robust evidence. Quercetin against COVID-19 does not have tough clinical evidence. Strategies to improve its bioavailability and/or to develop its effective derivatives are needed. Well-designed RCTs are also crucial to confirm their effectiveness in the future.

The Key to Increase Immunogenicity of Next-Generation COVID-19 Vaccines Lies in the Inclusion of the SARS-CoV-2 Nucleocapsid Protein

Vaccination is one of the most effective prophylactic public health interventions for the prevention of infectious diseases such as coronavirus disease (COVID-19). Considering the ongoing need for new COVID-19 vaccines, it is crucial to modify our approach and incorporate more conserved regions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to effectively address emerging viral variants. The nucleocapsid protein is a structural protein of SARS-CoV-2 that is involved in replication and immune responses. Furthermore, this protein offers significant advantages owing to the minimal accumulation of mutations over time and the inclusion of key T-cell epitopes critical for SARS-CoV-2 immunity. A novel strategy that may be suitable for the new generation of vaccines against COVID-19 is to use a combination of antigens, including the spike and nucleocapsid proteins, to elicit robust humoral and potent cellular immune responses, along with long-lasting immunity. The strategic use of multiple antigens aims to enhance vaccine efficacy and broaden protection against viruses, including their variants. The immune response against the nucleocapsid protein from other coronavirus is long-lasting, and it can persist up to 11 years post-infection. Thus, the incorporation of nucleocapsids (N) into vaccine design adds an important dimension to vaccination efforts and holds promise for bolstering the ability to combat COVID-19 effectively. In this review, we summarize the preclinical studies that evaluated the use of the nucleocapsid protein as antigen. This study discusses the use of nucleocapsid alone and its combination with spike protein or other proteins of SARS-CoV-2.

From intramuscular to nasal: unleashing the potential of nasal spray vaccines against coronavirus disease 2019

Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected 700 million people worldwide since its outbreak in 2019. The current pandemic strains, including Omicron and its large subvariant series, exhibit strong transmission and stealth. After entering the human body, the virus first infects nasal epithelial cells and invades host cells through the angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 on the host cell surface. The nasal cavity is an important body part that protects against the virus. Immunisation of the nasal mucosa produces immunoglobulin A antibodies that effectively neutralise viruses. Saline nasal irrigation, a type of physical therapy, can reduce the viral load in the nasal cavity and prevent viral infections to some extent. As a commonly used means to fight SARS-CoV-2, the intramuscular (IM) vaccine can induce the human body to produce a systemic immune response and immunoglobulin G antibody; however, the antibody is difficult to distribute to the nasal mucosa in time and cannot achieve a good preventive effect. Intranasal (IN) vaccines compensate for the shortcomings of IM vaccines, induce mucosal immune responses, and have a better effect in preventing infection. In this review, we discuss the nasal defence barrier, the harm caused by SARS-CoV-2, the mechanism of its invasion into host cells, nasal cleaning, IM vaccines and IN vaccines, and suggest increasing the development of IN vaccines, and use of IN vaccines as a supplement to IM vaccines.

Mental health and insomnia problems in healthcare workers after the COVID-19 pandemic: A multicenter cross-sectional study

BACKGROUND

Healthcare workers (HCWs) are at increased risk of contracting coronavirus disease 2019 (COVID-19) as well as worsening mental health problems and insomnia. These problems can persist for a long period, even after the pandemic. However, less is known about this topic.

AIM

To analyze mental health, insomnia problems, and their influencing factors in HCWs after the COVID-19 pandemic.

METHODS

This multicenter cross-sectional, hospital-based study was conducted from June 1, 2023 to June 30, 2023, which was a half-year after the end of the COVID-19 emergency. Region-stratified population-based cluster sampling was applied at the provincial level for Chinese HCWs. Symptoms such as anxiety, depression, and insomnia were evaluated by the Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, and Insomnia Severity Index. Factors influencing the symptoms were identified by multivariable logistic regression.

RESULTS

A total of 2000 participants were invited, for a response rate of 70.6%. A total of 1412 HCWs [618 (43.8%) doctors, 583 (41.3%) nurses and 211 (14.9%) nonfrontline], 254 (18.0%), 231 (16.4%), and 289 (20.5%) had symptoms of anxiety, depression, and insomnia, respectively; severe symptoms were found in 58 (4.1%), 49 (3.5%), and 111 (7.9%) of the participants. Nurses, female sex, and hospitalization for COVID-19 were risk factors for anxiety, depression, and insomnia symptoms; moreover, death from family or friends was a risk factor for insomnia symptoms. During the COVID-19 outbreak, most [1086 (76.9%)] of the participating HCWs received psychological interventions, while nearly all [994 (70.4%)] of them had received public psychological education. Only 102 (7.2%) of the HCWs received individual counseling from COVID-19.

CONCLUSION

Although the mental health and sleep problems of HCWs were relieved after the COVID-19 pandemic, they still faced challenges and greater risks than did the general population. Identifying risk factors would help in providing targeted interventions. In addition, although a major proportion of HCWs have received public psychological education, individual interventions are still insufficient.

SARS-CoV-2 Neutralization Assays Used in Clinical Trials: A Narrative Review

Since the emergence of COVID-19, extensive research efforts have been undertaken to accelerate the development of multiple types of vaccines to combat the pandemic. These include inactivated, recombinant subunit, viral vector, and nucleic acid vaccines. In the development of these diverse vaccines, appropriate methods to assess vaccine immunogenicity are essential in both preclinical and clinical studies. Among the biomarkers used in vaccine evaluation, the neutralizing antibody level serves as a pivotal indicator for assessing vaccine efficacy. Neutralizing antibody detection methods can mainly be classified into three types: the conventional virus neutralization test, pseudovirus neutralization test, and surrogate virus neutralization test. Importantly, standardization of these assays is critical for their application to yield results that are comparable across different laboratories. The development and use of international or regional standards would facilitate assay standardization and facilitate comparisons of the immune responses induced by different vaccines. In this comprehensive review, we discuss the principles, advantages, limitations, and application of different SARS-CoV-2 neutralization assays in vaccine clinical trials. This will provide guidance for the development and evaluation of COVID-19 vaccines.

In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development

Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent sequences (SCSs) in the spike protein are present in the human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against human proteins. To evaluate this possibility of "molecular mimicry" in silico and in vitro, we exhaustively identified common SCSs (cSCSs) found both in spike and human proteins bioinformatically. The commonality of SCSs between the two systems seemed to be coincidental, and only some cSCSs were likely to be relevant to potential self-epitopes based on three-dimensional information. Among three antibodies raised against cSCS-containing spike peptides, only the antibody against EPLDVL showed high affinity for the spike protein and reacted with an EPLDVL-containing peptide from the human unc-80 homolog protein. Western blot analysis revealed that this antibody also reacted with several human proteins expressed mainly in the small intestine, ovary, and stomach. Taken together, these results showed that most cSCSs are likely incapable of inducing autoantibodies but that at least EPLDVL functions as a self-epitope, suggesting a serious possibility of infection-induced or vaccine-induced autoantibodies in humans. High-risk cSCSs, including EPLDVL, should be excluded from vaccine epitopes to prevent potential autoimmune disorders.

COVID-19 Vaccine Hesitancy: Umbrella Review of Systematic Reviews and Meta-Analysis

BACKGROUND

The unprecedented emergence of the COVID-19 pandemic necessitated the development and global distribution of vaccines, making the understanding of global vaccine acceptance and hesitancy crucial to overcoming barriers to vaccination and achieving widespread immunization.

OBJECTIVE

This umbrella review synthesizes findings from systematic reviews and meta-analyses to provide insights into global perceptions on COVID-19 vaccine acceptance and hesitancy across diverse populations and regions.

METHODS

We conducted a literature search across major databases to identify systematic reviews and meta-analysis that reported COVID-19 vaccine acceptance and hesitancy. The AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews) criteria were used to assess the methodological quality of included systematic reviews. Meta-analysis was performed using STATA 17 with a random effect model. The data synthesis is presented in a table format and via a narrative.

RESULTS

Our inclusion criteria were met by 78 meta-analyses published between 2021 and 2023. Our analysis revealed a moderate vaccine acceptance rate of 63% (95% CI 0.60%-0.67%) in the general population, with significant heterogeneity (I2 = 97.59%). Higher acceptance rates were observed among health care workers and individuals with chronic diseases, at 64% (95% CI 0.57%-0.71%) and 69% (95% CI 0.61%-0.76%), respectively. However, lower acceptance was noted among pregnant women, at 48% (95% CI 0.42%-0.53%), and parents consenting for their children, at 61.29% (95% CI 0.56%-0.67%). The pooled vaccine hesitancy rate was 32% (95% CI 0.25%-0.39%) in the general population. The quality assessment revealed 19 high-quality, 38 moderate-quality, 15 low-quality, and 6 critically low-quality meta-analyses.

CONCLUSIONS

This review revealed the presence of vaccine hesitancy globally, emphasizing the necessity for population-specific, culturally sensitive interventions and clear, credible information dissemination to foster vaccine acceptance. The observed disparities accentuate the need for continuous research to understand evolving vaccine perceptions and to address the unique concerns and needs of diverse populations, thereby aiding in the formulation of effective and inclusive vaccination strategies.

TRIAL REGISTRATION

PROSPERO CRD42023468363; https://tinyurl.com/2p9kv9cr.

Comprehensive evaluation of T7 promoter for enhanced yield and quality in mRNA production

The manufacturing of mRNA vaccines relies on cell-free based systems that are easily scalable and flexible compared with the traditional vaccine manufacturing processes. Typically, standard processes yield 2 to 5 g L-1 of mRNA, with recent process optimisations increasing yields to 12 g L-1. However, increasing yields can lead to an increase in the production of unwanted by-products, namely dsRNA. It is therefore imperative to reduce dsRNA to residual levels in order to avoid intensive purification steps, enabling cost-effective manufacturing processes. In this work, we exploit sequence modifications downstream of the T7 RNA polymerase promoter to increase mRNA yields whilst simultaneously minimising dsRNA. In particular, transcription performance was optimised by modifying the sequence downstream of the T7 promoter with additional AT-rich sequences. We have identified variants that were able to produce higher amounts of mRNA (up to 14 g L-1) in 45 min of reaction. These variants exhibited up to a 30% reduction in dsRNA byproduct levels compared to a wildtype T7 promoter, and have similar EGFP protein expression. The results show that optimising the non-coding regions can have an impact on mRNA production yields and quality, reducing overall manufacturing costs.

Factors associated with mortality of elderly people due to COVID-19: Protocol for systematic review and meta-analysis

INTRODUCTION

The COVID-19 pandemic has become a significant health crisis, marked by high mortality rates on a global scale, with mortality from the disease being notably concentrated among the elderly due to various factors.

OBJECTIVE

This study aims to investigate the biological and non-biological factors associated with COVID-19 mortality rates among the elderly worldwide.

METHODS

The following databases will be consulted: PubMed, Scopus, EMBASE, Web of Science and ScienceDirect. Longitudinal observational studies (cohort and case-control-risk factors) will be included. The risk of bias, defined as low, moderate, high, will be assessed using the National Heart, Lung and Blood Institute (NHLBI) Quality Assessment Tool for observational cohort and cross-sectional studies. Two independent authors will conduct the searches, and any possible disagreements will be resolved by a third author. Heterogeneity between study results will be assessed using a standard X2 test with a significance level of 0.05, and an I2 value will be calculated to further assess heterogeneity. The random effects model for meta-analyses will be adopted to distribute the weight between the studies and standardize their contributions. The meta-analyses will be conducted using RevMan software.

DISCUSSION

Despite the numerous publications on COVID-19 mortality among the elderly, there is still a gap in knowledge, as there is no systematic review and meta-analysis that summarizes the main biological and non-biological associated factors globally.

CONCLUSION

The results of this study will consolidate the latest evidence and address gaps in the overall understanding of biological or non-biological associated factors. This knowledge will facilitate the development of appropriate health strategies for this demographic group and pave the way for further research.

TRIAL REGISTRATION

PROSPERO (CRD42023400873).

Validation and Suitability Assessment of Multiplex Mesoscale Discovery Immunogenicity Assay for Establishing Serological Signatures Using Vaccinated, Non-Vaccinated and Breakthrough SARS-CoV-2 Infected Cases

Antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are multi-targeted and variable over time. Multiplex quantitative serological assays are needed to provide accurate and robust seropositivity data for the establishment of serological signatures during vaccination and or infection. We describe here the validation and evaluation of an electro-chemiluminescence (ECL)-based Mesoscale Discovery assay (MSD) for estimation of total and functional IgG relative to SARS-CoV-2 spike, nucleocapsid and receptor binding (RBD) proteins in human serum samples to establish serological signatures of SARS-CoV-2 natural infection and breakthrough cases. The 9-PLEX assay was validated as per ICH, EMA, and US FDA guidelines using a panel of sera samples, including the NIBSC/WHO reference panel (20/268). The assay demonstrated high specificity and selectivity in inhibition assays, wherein the homologous inhibition was more than 85% and heterologous inhibition was below 10%. The assay also met predetermined acceptance criteria for precision (CV < 20%), accuracy (70-130%) and dilutional linearity. The method's applicability to serological signatures was demonstrated using sera samples (n = 45) representing vaccinated, infected and breakthrough cases. The method was able to establish distinct serological signatures and thus provide a potential tool for seroprevalence of SARS-CoV-2 during vaccination or infection.

Current Progress, Challenges and Prospects in the Development of COVID-19 Vaccines

The COVID-19 pandemic has resulted in over 772 million confirmed cases, including nearly 7 million deaths, according to the World Health Organization (WHO). Leveraging rapid development, accelerated vaccine approval processes, and large-scale production of various COVID-19 vaccines using different technical platforms, the WHO declared an end to the global health emergency of COVID-19 on May 5, 2023. Current COVID-19 vaccines encompass inactivated, live attenuated, viral vector, protein subunit, nucleic acid (DNA and RNA), and virus-like particle (VLP) vaccines. However, the efficacy of these vaccines is diminishing due to the constant mutation of SARS-CoV-2 and the heightened immune evasion abilities of emerging variants. This review examines the impact of the COVID-19 pandemic, the biological characteristics of the virus, and its diverse variants. Moreover, the review underscores the effectiveness, advantages, and disadvantages of authorized COVID-19 vaccines. Additionally, it analyzes the challenges, strategies, and future prospects of developing a safe, broad-spectrum vaccine that confers sufficient and sustainable immune protection against new variants of SARS-CoV-2. These discussions not only offer insight for the development of next-generation COVID-19 vaccines but also summarize experiences for combating future emerging viruses.

A Cocktail of Lipid Nanoparticle-mRNA Vaccines Broaden Immune Responses against β-Coronaviruses in a Murine Model

Severe acute respiratory syndrome (SARS)-coronavirus (CoV), Middle Eastern respiratory syndrome (MERS)-CoV, and SARS-CoV-2 have seriously threatened human life in the 21st century. Emerging and re-emerging β-coronaviruses after the coronavirus disease 2019 (COVID-19) epidemic remain possible highly pathogenic agents that can endanger human health. Thus, pan-β-coronavirus vaccine strategies to combat the upcoming dangers are urgently needed. In this study, four LNP-mRNA vaccines, named O, D, S, and M, targeting the spike protein of SARS-CoV-2 Omicron, Delta, SARS-CoV, and MERS-CoV, respectively, were synthesized and characterized for purity and integrity. All four LNP-mRNAs induced effective cellular and humoral immune responses against the corresponding spike protein antigens in mice. Furthermore, LNP-mRNA S and D induced neutralizing antibodies against SARS-CoV and SARS-CoV-2, which failed to cross-react with MERS-CoV. Subsequent evaluation of sequential and cocktail immunizations with LNP-mRNA O, D, S, and M effectively elicited broad immunity against SARS-CoV-2 variants, SARS-CoV, and MERS-CoV. A direct comparison of the sequential with cocktail regimens indicated that the cocktail vaccination strategy induced more potent neutralizing antibodies and T-cell responses against heterotypic viruses as well as broader antibody activity against pan-β-coronaviruses. Overall, these results present a potential pan-β-coronavirus vaccine strategy for improved preparedness prior to future coronavirus threats.

Unveiling the Antiviral Capabilities of Targeting Human Dihydroorotate Dehydrogenase against SARS-CoV-2

The urgent need for effective treatments against emerging viral diseases, driven by drug-resistant strains and new viral variants, remains critical. We focus on inhibiting the human dihydroorotate dehydrogenase (HsDHODH), one of the main enzymes responsible for pyrimidine nucleotide synthesis. This strategy could impede viral replication without provoking resistance. We evaluated naphthoquinone fragments, discovering potent HsDHODH inhibition with IC50 ranging from 48 to 684 nM, and promising in vitro anti-SARS-CoV-2 activity with EC50 ranging from 1.2 to 2.3 μM. These compounds exhibited low toxicity, indicating potential for further development. Additionally, we employed computational tools such as molecular docking and quantitative structure-activity relationship (QSAR) models to analyze protein-ligand interactions, revealing that these naphthoquinones exhibit a protein binding pattern similar to brequinar, a potent HsDHODH inhibitor. These findings represent a significant step forward in the search for effective antiviral treatments and have great potential to impact the development of new broad-spectrum antiviral drugs.

Ferritin-binding and ubiquitination-modified mRNA vaccines induce potent immune responses and protective efficacy against SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) incessantly engenders mutating strains via immune escape mechanisms, substantially escalating the risk of severe acute respiratory syndrome. In this context, the urgent development of innovative and efficacious mRNA vaccines is imperative. In our study, we synthesized six unique mRNA vaccine formulations: the Receptor Binding Domain (RBD) monomer vaccine, RBD dimer (2RBD) vaccine, RBD-Ferritin (RBD-Fe) vaccine, ubiquitin-modified wild-type Nucleocapsid gene (WT-N) vaccine, rearranged Nucleocapsid gene (Re-N) vaccine, and an epitope-based (COVID-19 epitope) vaccine, all encapsulated within the lipid nanoparticle SM102. Immunization studies conducted on C57BL/6 mice with these vaccines revealed that the RBD monomer, RBD dimer (2RBD), and RBD-Fe vaccines elicited robust titers of specific antibodies, including neutralizing antibodies. In contrast, the wild-type N gene (WT-N), rearrange N gene (Re-N), and COVID-19 epitope vaccines predominantly induced potent cellular immune responses. Protective efficacy assays in golden hamsters demonstrated that vaccinated cohorts showed significant reduction in lung pathology, markedly lower viral loads in the lungs, nasal turbinates, and trachea, and substantially reduced transcriptional and expression levels of pro-inflammatory cytokines. Overall, our vaccine candidates pave the way for novel strategies in vaccine development against various infectious agents and establish a critical foundation for the formulation of advanced vaccines targeting emerging pathogens.

Single MVA-SARS-2-ST/N Vaccination Rapidly Protects K18-hACE2 Mice against a Lethal SARS-CoV-2 Challenge Infection

The sudden emergence of SARS-CoV-2 demonstrates the need for new vaccines that rapidly protect in the case of an emergency. In this study, we developed a recombinant MVA vaccine co-expressing SARS-CoV-2 prefusion-stabilized spike protein (ST) and SARS-CoV-2 nucleoprotein (N, MVA-SARS-2-ST/N) as an approach to further improve vaccine-induced immunogenicity and efficacy. Single MVA-SARS-2-ST/N vaccination in K18-hACE2 mice induced robust protection against lethal respiratory SARS-CoV-2 challenge infection 28 days later. The protective outcome of MVA-SARS-2-ST/N vaccination correlated with the activation of SARS-CoV-2-neutralizing antibodies (nABs) and substantial amounts of SARS-CoV-2-specific T cells especially in the lung of MVA-SARS-2-ST/N-vaccinated mice. Emergency vaccination with MVA-SARS-2-ST/N just 2 days before lethal SARS-CoV-2 challenge infection resulted in a delayed onset of clinical disease outcome in these mice and increased titers of nAB or SARS-CoV-2-specific T cells in the spleen and lung. These data highlight the potential of a multivalent COVID-19 vaccine co-expressing S- and N-protein, which further contributes to the development of rapidly protective vaccination strategies against emerging pathogens.

Overview of childhood vaccination coverage in Brazil and the impact of the COVID-19 pandemic: Is our children's health at risk? A review of pre-COVID-19 periods and during the COVID-19 pandemic

Introduction

The coronavirus disease (COVID)-19 has had a great impact on several aspects related to the population's health, including the vaccination adherence rate. This study describes how childhood vaccination coverage (CVC) in Brazil was affected by the pandemic in the period from 2020 to 2022 and explores the relationship between this data and the Human Development Index (HDI), and the number of votes received in the government with a right-wing political ideology.

Methods

An ecological analysis of CVC was carried out including 12 vaccines. The HDI was evaluated considering the HDI-General, HDI-Income, HDI-Longevity, and HDI-Education. The percentage of valid votes received by the former president (right-wing political ideology) was also obtained. Spearman correlation tests were applied to compare markers.

Results

During the period analyzed, it was observed a linear growth trend in CVC between 2015 and 2018 regarding all vaccines. However, from 2018 onwards, after the presidential elections in Brazil, the CVC reduced significantly, showing an even more pronounced decrease with the start of the COVID-19 pandemic. This reduction in CVC observed for some vaccines was related to the higher percentage of votes for the government with a right-wing political ideology, especially in relation to the BCG (bacillus Calmette and Guerin) and pentavalent (protecting against diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b bacteria) vaccines. In addition, when analyzing the HDI, it was observed that the lowest values of this indicator were associated with a more expressive reduction in CVC, mainly related to yellow fever, pentavalent, 10-valent pneumococcal conjugate, Human rotavirus, and triple viral (protecting against measles, mumps, and rubella - MMR) vaccines.

Conclusion

Although Brazil has a successful and exemplary record in combating several diseases, mainly due to the high rate of CVC, the continuous reduction in this coverage must be thoroughly evaluated by health managers.

Modularized viromimetic polymer nanoparticle vaccines (VPNVaxs) to elicit durable and effective humoral immune responses

Virus-like particle (VLP) vaccines had shown great potential during the COVID-19 pandemic, and was thought to be the next generation of antiviral vaccine technology due to viromimetic structures. However, the time-consuming and complicated processes in establishing a current recombinant-protein-based VLP vaccine has limited its quick launch to the out-bursting pandemic. To simplify and optimize VLP vaccine design, we herein report a kind of viromimetic polymer nanoparticle vaccine (VPNVax), with subunit receptor-binding domain (RBD) proteins conjugated to the surface of polyethylene glycol-b-polylactic acid (PEG-b-PLA) nanoparticles for vaccination against SARS-CoV-2. The preparation of VPNVax based on synthetic polymer particle and chemical post-conjugation makes it possible to rapidly replace the antigens and construct matched vaccines at the emergence of different viruses. Using this modular preparation system, we identified that VPNVax with surface protein coverage of 20%-25% had the best immunostimulatory activity, which could keep high levels of specific antibody titers over 5 months and induce virus neutralizing activity when combined with an aluminum adjuvant. Moreover, the polymer nano-vectors could be armed with more immune-adjuvant functions by loading immunostimulant agents or chemical chirality design. This VPNVax platform provides a novel kind of rapidly producing and efficient vaccine against different variants of SARS-CoV-2 as well as other viral pandemics.

A semi-quantitative visual lateral flow immunoassay for SARS-CoV-2 antibody detection for the follow-up of immune response to vaccination or recovery

The lateral flow immunoassay (LFIA) technique is largely employed for the point-of-care detection of antibodies especially for revealing the immune response in serum. Visual LFIAs usually provide the qualitative yes/no detection of antibodies, while quantification requires some equipment, making the assay more expensive and complicated. To achieve visual semi-quantification, the alignment of several lines (made of the same antigen) along a LFIA strip has been proposed. The numbering of the reacting lines has been used to correlate with the quantity of some biomarkers in serum. Here, we designed the first semiquantitative LFIA for detecting antibodies and applied it to classify the immune response to SARS-CoV-2 raised by vaccination or natural infection. We used a recombinant spike receptor-binding domain (RBD) as the specific capture reagent to draw two test lines. The detection reagent was selected among three possible ligands that are able to bind to anti-spike human antibodies: the same RBD, staphylococcal protein A, and anti-human immunoglobulin G antibodies. The most convenient detector, adsorbed on gold nanoparticles, was chosen based on the highest correlation with an antibody titre of 171 human sera, measured by a reference serological method, and was the RBD (Spearman's rho = 0.84). Incorporated into the semiquantitative LFIA, it confirmed the ability to discriminate high- and low-titre samples and to classify them into two classes (Dunn's test, P < 0.05). The proposed approach enabled the semiquantification of the immune response to SARS-CoV-2 by the unaided eye observation, thus overcoming the requirement of costly and complicated equipment, and represents a general strategy for the development of semiquantitative serological LFIAs.

Cepharanthine analogs mining and genomes of Stephania accelerate anti-coronavirus drug discovery

Cepharanthine is a secondary metabolite isolated from Stephania. It has been reported that it has anti-conronaviruses activities including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Here, we assemble three Stephania genomes (S. japonica, S. yunnanensis, and S. cepharantha), propose the cepharanthine biosynthetic pathway, and assess the antiviral potential of compounds involved in the pathway. Among the three genomes, S. japonica has a near telomere-to-telomere assembly with one remaining gap, and S. cepharantha and S. yunnanensis have chromosome-level assemblies. Following by biosynthetic gene mining and metabolomics analysis, we identify seven cepharanthine analogs that have broad-spectrum anti-coronavirus activities, including SARS-CoV-2, Guangxi pangolin-CoV (GX_P2V), swine acute diarrhoea syndrome coronavirus (SADS-CoV), and porcine epidemic diarrhea virus (PEDV). We also show that two other genera, Nelumbo and Thalictrum, can produce cepharanthine analogs, and thus have the potential for antiviral compound discovery. Results generated from this study could accelerate broad-spectrum anti-coronavirus drug discovery.

Efficacy of adjuvant-associated COVID-19 vaccines against SARS-CoV-2 variants of concern in randomized controlled trials: A systematic review and meta-analysis

BACKGROUND

Adjuvants may enhance the efficacy of vaccines. however, the efficacy of adjuvant-associated COVID-19 vaccines (ACVs) remains unclear since the emergence of the COVID-19 pandemic. This study aimed to address this gap by conducting a systematic review and meta-analysis of the efficacy of ACVs against Severe Acute Respiratory Syndrome Coronavirus 2 CoV (SARS-CoV-2) variants of concern (VOC).

METHODS

A systematic search was conducted of randomized controlled trials (RCTs) evaluating the vaccine efficacy (VE) of ACVs against VOC (alpha, beta, gamma, delta, or Omicron), up to May 27, 2023. The DerSimonian-Laird random-effects model was used to assess VE with 95% confidence intervals (CI) through meta-analysis. Cochrane Risk of Bias tools were used to assess the risk of bias in RCTs.

RESULTS

Eight RCTs with 113,202 participants were included in the analysis, which incorporated 4 ACVs [Matrix-M (NVX-CoV2373), Alum (BBV152), CpG-1018/Alum (SCB-2019), and AS03 (CoVLP]). The pooled efficacy of full vaccination with ACVs against VOC was 88.0% (95% CI: 83.0-91.5). Full vaccination was effective against Alpha, Beta, Delta, and Gamma variants, with VE values of 93.66% (95% CI: 86.5-100.74), 64.70% (95% CI: 41.87-87.54), 75.95% (95% CI: 67.9-83.99), and 91.26% (95% CI: 84.35-98.17), respectively. Currently, there is a lack of RCT evidence regarding the efficacy of ACVs against the Omicron variant.

CONCLUSION

In this meta-analysis, it should be that full vaccination with ACVs has high efficacy against Alpha or Gamma variants and moderate efficacy against Beta and Delta variants. Notably, with the exception of the aluminum-adjuvanted vaccine, the other ACVs had moderate to high efficacy against the SARS-CoV-2 variant. This raises concerns about the effectiveness of ACVs booster vaccinations against Omicron.

Research progress on emulsion vaccine adjuvants

Vaccination is the most cost-effective method for preventing various infectious diseases. Compared with conventional vaccines, new-generation vaccines, especially recombinant protein or synthetic peptide vaccines, are safer but less immunogenic than crude inactivated microbial vaccines. The immunogenicity of these vaccines can be enhanced using suitable adjuvants. This is the main reason why adjuvants are of great importance in vaccine development. Several novel human emulsion-based vaccine adjuvants (MF59, AS03) have been approved for clinical use. This paper reviews the research progress on emulsion-based adjuvants and focuses on their mechanism of action. An outlook can be provided for the development of emulsion-based vaccine adjuvants.

Protecting Human and Animal Health: The Road from Animal Models to New Approach Methods

Animals and animal models have been invaluable for our current understanding of human and animal biology, including physiology, pharmacology, biochemistry, and disease pathology. However, there are increasing concerns with continued use of animals in basic biomedical, pharmacological, and regulatory research to provide safety assessments for drugs and chemicals. There are concerns that animals do not provide sufficient information on toxicity and/or efficacy to protect the target population, so scientists are utilizing the principles of replacement, reduction, and refinement (the 3Rs) and increasing the development and application of new approach methods (NAMs). NAMs are any technology, methodology, approach, or assay used to understand the effects and mechanisms of drugs or chemicals, with specific focus on applying the 3Rs. Although progress has been made in several areas with NAMs, complete replacement of animal models with NAMs is not yet attainable. The road to NAMs requires additional development, increased use, and, for regulatory decision making, usually formal validation. Moreover, it is likely that replacement of animal models with NAMs will require multiple assays to ensure sufficient biologic coverage. The purpose of this manuscript is to provide a balanced view of the current state of the use of animal models and NAMs as approaches to development, safety, efficacy, and toxicity testing of drugs and chemicals. Animals do not provide all needed information nor do NAMs, but each can elucidate key pieces of the puzzle of human and animal biology and contribute to the goal of protecting human and animal health. SIGNIFICANCE STATEMENT: Data from traditional animal studies have predominantly been used to inform human health safety and efficacy. Although it is unlikely that all animal studies will be able to be replaced, with the continued advancement in new approach methods (NAMs), it is possible that sometime in the future, NAMs will likely be an important component by which the discovery, efficacy, and toxicity testing of drugs and chemicals is conducted and regulatory decisions are made.

Relative effectiveness of bivalent COVID-19 vaccine: a systematic review and meta-analysis

Objective

The rapid development of COVID-19 bivalent vaccines (BVs) has encompassed both the original virus strains and the variant strain. However, the effectiveness of BVs is largely unknown. Therefore, we conducted a systematic review and meta-analysis of the effectiveness of BVs.

Methods

Literature research was conducted through PubMed, Cochrane Library, Embase, and Web of Science up until November 4, 2023. Both randomized control trials and observational studies were considered for inclusion. Pooled estimates were calculated using a random effects model. The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias in cohort and case-control studies.

Results

A total of 1,174 articles were reviewed and 22 eligible studies were included. All included studies were observational (15 cohort studies, 7 case-control studies). The total number of participants was 39,673,160, and the number of people vaccinated with BVs as an intervention group was 11,585,182. Two mRNA BVs were mainly involved, including the ancestral strain and the BA.1 or BA.4-5 variants. Meta-analysis results showed, compared with the monovalent vaccines (MVs), the relative effectiveness (rVE) of the BVs in COVID-19-associated infections/symptomatic infections, illnesses, hospitalizations, and deaths was 30.90% [95% confidence interval (CI), 8.43-53.37], 39.83% (95% CI, 27.34-52.32), 59.70% (95% CI, 44.08-75.32), and 72.23% (95% CI, 62.08-82.38), respectively. For those aged 50 years and older, BVs provided an additional 49.69% (95% CI, 41.44-57.94) effective protection compared with MVs. During the dominance period of the omicron XBB variant strain, BVs provided an additional 47.63% (95% CI, 27.45-67.82) effective protection compared with MVs.

Conclusion

Our findings show that the rVE of BVs in preventing COVID-19-associated infections, symptomatic infections, illnesses, hospitalizations, and deaths is higher compared to MVs. Particularly for people over 50 years of age and during the Omicron variant XBB dominance phase, BVs provided superior protection. Therefore, BVs may have a broader application in the prevention and control of coronaviruses variant.

Low uptake of COVID-19 booster doses among elderly cancer patients in China: A multicentre cross-sectional study

Background

Vaccination is a crucial measure to control the spread of coronavirus disease 2019 (COVID-19) pandemic. The elderly and cancer populations both are more susceptible to SARS-CoV-2 and have higher mortality. However, the uptake of COVID-19 vaccine booster doses among elderly cancer patients remains unclear. This study aimed to investigate the prevalence and associates of COVID-19 vaccine booster doses uptake in elderly cancer patients.

Methods

A multi-center cross-sectional survey was conducted in four general populations of China province from April to June 2022. Demographic and clinical characteristics, as well as COVID-19 vaccination status and reasons for not uptake booster doses, were collected through face-to-face interviews and medical records. Multivariable logistic regression models were performed to explore the associates of the first COVID-19 booster dose vaccination uptake of cancer patients.

Results

A total of 893 cancer patients were eventually included in this study, of which 279 (31.24%) were aged 65 or older and 614 (68.76%) were under 65 years old. The proportion of the first COVID-19 vaccine booster dose among cancer patients aged 65 and above was lower than among adults aged 65 (23.66 vs. 31.92%). Factors affecting individual-level variables among the aged 65 and above cancer patients group whether to uptake the first COVID-19 booster dose were negative attitudes toward COVID-19 vaccine booster dose, perceived subjective norm, perceived behavioural control, and other types of chronic disease. There is no significant difference in the incidence of related adverse reactions between the two age groups (P = 0.19).

Conclusions

Low uptake of COVID-19 vaccine booster doses among elderly cancer patients is a significant concern and implies high susceptibility and high fatality when facing the emergence of SARS Cov-2 outbreak. Efforts to improve vaccine education and accessibility, particularly in rural areas, may help increase uptake and reduce the spread of SARS-Cov-2.

Analysis of characteristics of and risk factors for otological symptoms after COVID-19 infection

The purpose of this study was to explore the characteristics of and risk factors for otological symptoms after contracting COVID-19. We invited 468 participants who had been infected with COVID-19 to participate in a survey. 310 (66.2%) were women and 158 (33.8%) were men. The mean age is 38.73 (12.21) years. The questionnaire included their basic information, symptoms and symptom duration after SARS-CoV-2 infection, number of vaccine doses received, and details regarding otological symptoms. In total, 106/468 (22.6%) participants experienced tinnitus, 66/468 (14.1%) hearing loss, 103/468 (22.0%) aural fullness, and 71/468 (15.2%) dizziness. Women were more prone to experience tinnitus (P = 0.022) and dizziness (P = 0.001) than men. The group with hearing loss were older (P = 0.025), and their initial COVID-19 symptoms lasted longer (P = 0.028) than those of patients without. Patients with aural fullness were more likely to experience fatigue than patients without (P = 0.002). Patients experiencing dizziness were more likely to experience pharyngalgia (P = 0.040) and fatigue (P = 0.005) than those without. The number of vaccine doses was positively associated with the resolution of otological symptoms (P = 0.035). Multiple logistic regression analysis revealed that sex was an independent risk factor for tinnitus (odds ratio [OR], 1.802; 95% confidence interval [CI], 1.099-2.953; P = 0.020), the duration of initial COVID-19 symptoms for hearing loss (OR, 1.055; 95% CI, 1.008-1.105; P = 0.023), and sex for dizziness (OR, 2.870; 95% CI, 1.489-5.535; P = 0.002). Sex, age, COVID-19-related fatigue, and the duration of initial COVID-19 symptoms may affect the occurrence of otological symptoms, and vaccines may aid their resolution.