Looking beyond COVID-19 vaccine phase 3 trials

Safety and efficiency of COVID-19 vaccine in North Africa

Background In the absence of a specific treatment for COVID-19, preventive measures have been implemented to control this pandemic and vaccination is one of them. However, it is crucial to verify the safety and efficiency of every vaccine. The aim was to determinate the predictive factors of side effects and reinfection after COVID-19 vaccine. Methods A cross-sectional study was conducted in February 2022 among Tunisians infected with COVID-19 between March 2020 and February 2022, using an online self-administered questionnaire. We conducted univariate and multivariate analyses using binary stepwise logistic regression. Results A total of 1541 was selected from 1911 individuals. Comorbidities affected a quarter of the population (22.3%). Before the initial infection, 39.3% had received full vaccination, and 8.7% had received partial vaccination. By February 2022, the majority (82.9%) had received at least two vaccine doses. The reinfection rate was 30.6%. All vaccines prior to the first infection was identified as a protective factor against reinfection. Inactivated virus vaccinations were less likely to induce adverse effects. Conclusion ach vaccine has its own set of advantages and disadvantages: mRNA-based vaccines had a higher incidence of side effects but all vaccines provided better protection against reinfection.

A vaccination-based COVID-19 model: Analysis and prediction using Hamiltonian Monte Carlo

Compartmental models have emerged as robust computational frameworks and have yielded remarkable success in the fight against COVID-19. This study proposes a vaccination-based compartmental model for COVID-19 transmission dynamics. The model reflects the specific stages of COVID-19 infection and integrates a vaccination strategy, allowing for a comprehensive analysis of how vaccination rates influence the disease spread. We fit this model to daily confirmed COVID-19 cases in Tennessee, United States of America (USA), from June 4 to November 26, 2021, in a Bayesian inference approach using the Hamiltonian Monte Carlo (HMC) algorithm. First, excluding vaccination dynamics from the model, we estimated key epidemiological parameters like infection, recovery, and disease-induced death rates. This analysis yielded a basic reproduction number (R 0 ) of 1.5. Second, we incorporated vaccination dynamics and estimated the vaccination rate for three vaccines: 0.0051 per day for both Pfizer and Moderna and 0.0059 per day for Janssen. The fitted curves show reductions in the epidemic peak for all three vaccines. Pfizer and Moderna vaccines bring the peak down from 8,029 infected cases to 5,616 infected cases, while the Janssen vaccine reduces it, to 6,493 infected cases. Simulations of the model by varying the vaccination rate and vaccine efficacy were performed. A highly effective vaccine (95% efficacy) with a daily vaccination rate of 0.006 halved COVID-19 infections, reducing cases from 8,029 to around 4,000. The results also show that the model's prediction accuracy for new observations improves with the number of observed data used to train the model.

Human and hamster sera correlate well in identifying antigenic drift among SARS-CoV-2 variants, including JN.1

Antigenic assessments of SARS-CoV-2 variants inform decisions to update COVID-19 vaccines. Primary infection sera are often used for assessments, but such sera are rare due to population immunity from SARS-CoV-2 infections and COVID-19 vaccinations. Here, we show that neutralization titers and breadth of matched human and hamster pre-Omicron variant primary infection sera correlate well and generate similar antigenic maps. The hamster antigenic map shows modest antigenic drift among XBB sub-lineage variants, with JN.1 and BA.4/BA.5 variants within the XBB cluster, but with fivefold to sixfold antigenic differences between these variants and XBB.1.5. Compared to sera following only ancestral or bivalent COVID-19 vaccinations, or with post-vaccination infections, XBB.1.5 booster sera had the broadest neutralization against XBB sub-lineage variants, although a fivefold titer difference was still observed between JN.1 and XBB.1.5 variants. These findings suggest that antibody coverage of antigenically divergent JN.1 could be improved with a matched vaccine antigen.IMPORTANCEUpdates to COVID-19 vaccine antigens depend on assessing how much vaccine antigens differ antigenically from newer SARS-CoV-2 variants. Human sera from single variant infections are ideal for discriminating antigenic differences among variants, but such primary infection sera are now rare due to high population immunity. It remains unclear whether sera from experimentally infected animals could substitute for human sera for antigenic assessments. This report shows that neutralization titers of variant-matched human and hamster primary infection sera correlate well and recognize variants similarly, indicating that hamster sera can be a proxy for human sera for antigenic assessments. We further show that human sera following an XBB.1.5 booster vaccine broadly neutralized XBB sub-lineage variants but titers were fivefold lower against the more recent JN.1 variant. These findings support updating the current COVID-19 vaccine variant composition and developing a framework for assessing antigenic differences in future variants using hamster primary infection sera.

Strategies for developing self-assembled nanoparticle vaccines against SARS-CoV-2 infection

In the recent history of the SARS-CoV-2 outbreak, vaccines have been a crucial public health tool, playing a significant role in effectively preventing infections. However, improving the efficacy while minimizing side effects remains a major challenge. In recent years, there has been growing interest in nanoparticle-based delivery systems aimed at improving antigen delivery efficiency and immunogenicity. Among these, self-assembled nanoparticles with varying sizes, shapes, and surface properties have garnered considerable attention. This paper reviews the latest advancements in the design and development of SARS-CoV-2 vaccines utilizing self-assembled materials, highlighting their advantages in delivering viral immunogens. In addition, we briefly discuss strategies for designing a broad-spectrum universal vaccine, which provides insights and ideas for dealing with possible future infectious sarbecoviruses.

Augmented humoral response to third and fourth dose of SARS-CoV-2 mRNA vaccines in lung transplant recipients

BACKGROUND

Since lung transplant recipients (LTRs) exhibit low immunogenicity after two doses of SARS-CoV-2 mRNA vaccines, optimal vaccine strategies for SARS-CoV-2 are required in LTRs. This study aimed to investigate the efficacy and safety of the third and fourth doses of the SARS-CoV-2 mRNA vaccines in LTRs.

METHODS

We conducted a single-center study of 73 LTRs and 23 healthy controls (HCs). Participants received two-to-four doses of SARS-CoV-2 mRNA vaccines. The LTRs were divided into three groups based on the number of vaccine dose. IgG titers against SARS-CoV-2 spike protein were measured, and adverse events were assessed. Factors associated with humoral response were analyzed using univariate and multivariate analyses.

RESULTS

The Dose 4 group (n = 27) had a higher humoral response rate (P = 0.018) and higher levels of anti-SARS-CoV-2 IgG antibody (P = 0.04) than the Dose 2 group (n = 14). The Dose 3 group (n = 32) had lower humoral response rates (P = 0.005) and levels of anti-SARS-CoV-2 IgG antibody (P = 0.0005) than the HCs (n = 23) even after the same dose. Systemic adverse events were milder in the LTRs than in the HCs (P < 0.05). Increased number of vaccine dose was identified as a predictor of positive humoral response (P = 0.021).

CONCLUSION

Booster doses of SARS-CoV-2 mRNA vaccines may enhance humoral response with mild adverse events in LTRs. Repeated vaccination might be warranted for LTRs to prevent SARS-CoV-2 infection.

Antiphospholipid syndrome in the era of COVID-19 - Two sides of a coin

In addition to the respiratory symptoms associated with COVID-19, the disease has consistently been linked to many autoimmune diseases such as systemic lupus erythematous and antiphospholipid syndrome (APS). APS in particular was of paramount significance due to its devastating clinical sequela. In fact, the hypercoagulable state seen in patients with acute COVID-19 and the critical role of anticoagulant treatment in affected individuals shed light on the possible relatedness between APS and COVID-19. Moreover, the role of autoimmunity in the assumed association is not less important especially with the accumulated data available regarding the autoimmunity-triggering effect of SARS-CoV-2 infection. This is furtherly strengthened at the time patients with COVID-19 manifested antiphospholipid antibodies of different types following infection. Additionally, the severe form of the APS spectrum, catastrophic APS (CAPS), was shown to have overlapping characteristics with severe COVID-19 such as cytokine storm and multi-organ failure. Interestingly, COVID vaccine-induced autoimmune phenomena described in the medical literature have pointed to an association with APS. Whether the antiphospholipid antibodies were present or de novo, COVID vaccine-induced vascular thrombosis in certain individuals necessitates further investigations regarding the possible mechanisms involved. In our current paper, we aimed to focus on the associations mentioned, their implications, importance, and consequences.

Evaluation of the COVID-19 vaccine effectiveness on the outcomes of COVID 19 disease in Iran: a test-negative case-control study

Introduction

This study measures the COVID-19 vaccine effectiveness (CVE) against hospital admission and severe COVID-19.

Methods

This study is a test-negative case-control design using data from eight provinces in April, 2021 until March, 2022. The individuals were classified as cases and controls based on the results of the RT-PCR test for SARS-CoV-2 and matched based on the timing of the test being conducted as well as the timing of hospital admission. The measure of association was an odds ratio (OR) by univariate and multiple logistic regression. The multiple logistic regression has been carried out to take confounding factors and potential effect modifiers into account. The CVE was computed as CVE = (1 - OR)*100 with 95% confidence interval.

Results

Among 19314 admitted patients, of whom 13216 (68.4%) were cases and 6098 (31.6%) were controls, 1313 (6.8%) died. From total, 5959 (30.8%) patients had received the vaccine in which one, two, and booster doses were 2443 (12.6%), 2796 (14.5٪), and 720 (3.7٪), respectively. The estimated adjusted effectiveness of only one dose, two doses and booter vaccination were 22% (95% CI: 14%-29%), 35% (95% CI: 29%-41%) and 33% (95% CI: 16%-47%), respectively. In addition, the adjusted vaccine effectiveness against severe outcome was 33% (95% CI: 19%- 44%), 34% (95% CI: 20%- 45%) and 20% (95% CI: -29%- 50%) for those who received one, two and booster vaccinations, respectively.

Conclusion

Our study concluded that full vaccination, though less effective compared to similar studies elsewhere, decreased hospital admissions and deaths from COVID-19 in Iran, particularly during the Delta variant period, with an observed decline during the Omicron variant dominance.

Serological responses and clinical outcomes following a three-dose primary COVID-19 vaccine schedule in kidney transplant recipients and people on dialysis

Objectives

Despite vaccination strategies, people with chronic kidney disease, particularly kidney transplant recipients (KTRs), remained at high risk of poor COVID-19 outcomes. We assessed serological responses to the three-dose COVID-19 vaccine schedule in KTRs and people on dialysis, as well as seroresponse predictors and the relationship between responses and breakthrough infection.

Methods

Plasma from 30 KTRs and 17 people receiving dialysis was tested for anti-Spike receptor binding domain (RBD) IgG and neutralising antibodies (NAb) to the ancestral and Omicron BA.2 variant after Doses 2 and 3 of vaccination.

Results

After three doses, KTRs achieved lower anti-Spike RBD IgG levels (P < 0.001) and NAb titres than people receiving dialysis (P = 0.002). Seropositive cross-reactive Omicron neutralisation levels were achieved in 11/27 (40.7%) KTRs and 11/14 (78.6%) dialysis recipients. ChAdOx1/viral-vector vaccine type, higher mycophenolate dose (> 1 g per day) and lower absolute B-cell counts predicted poor serological responses in KTRs. ChAdOx-1 vaccine type and higher monocyte counts were negative predictors in dialysis recipients. Among ancestral NAb seroresponders, higher NAb levels positively correlated with higher Omicron neutralisation (R = 0.9, P < 0.001). More KTRs contracted SARS-CoV-2 infection (14/30; 47%) than dialysis recipients (5/17; 29%) and had more severe disease. Those with breakthrough infections had significantly lower median interdose incremental change in anti-Spike RBD IgG and ancestral NAb titres.

Conclusion

Serological responses to COVID-19 vaccines in KTRs lag behind their dialysis counterparts. KTRs remained at high risk of breakthrough infection after their primary vaccination schedule underlining their need for booster doses, strict infection prevention measures and close surveillance.

Engineering customized nanovaccines for enhanced cancer immunotherapy

Nanovaccines have gathered significant attention for their potential to elicit tumor-specific immunological responses. Despite notable progress in tumor immunotherapy, nanovaccines still encounter considerable challenges such as low delivery efficiency, limited targeting ability, and suboptimal efficacy. With an aim of addressing these issues, engineering customized nanovaccines through modification or functionalization has emerged as a promising approach. These tailored nanovaccines not only enhance antigen presentation, but also effectively modulate immunosuppression within the tumor microenvironment. Specifically, they are distinguished by their diverse sizes, shapes, charges, structures, and unique physicochemical properties, along with targeting ligands. These features of nanovaccines facilitate lymph node accumulation and activation/regulation of immune cells. This overview of bespoke nanovaccines underscores their potential in both prophylactic and therapeutic applications, offering insights into their future development and role in cancer immunotherapy.

Vaccine adjuvants: current status, research and development, licensing, and future opportunities

Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.

Measuring COVID-19 vaccine hesitancy among college students with disabilities: Sociodemographic and psychological correlates of COVID-19 vaccine hesitancy

Objective: The purpose of the study was to explore characteristics of vaccine hesitancy and behaviors among college students with disabilities. Participants and Methods: Participants consisted of 105 college students with disabilities (Mage=26.82, SD = 8.42), and a majority of participants were female (69.5%) and Hispanic (85%). Results: No demographic differences were observed in vaccine hesitancy scores in this sample. Those who do not know where to get reliable information about COVID-19 vaccination had higher scores on vaccine hesitancy than those who know how to obtain reliable information; and participants who had a negative experience with a previous vaccination also had higher scores of vaccine hesitancy. Additionally, findings demonstrated COVID-19 vaccine hesitancy scores were negatively associated with openness to experience personality trait and COVID-19-related perceived stress. Conclusions: Implications provide additional insight into factors associated with vaccine hesitancy among college students with disabilities.

Immune response stability to the SARS-CoV-2 mRNA vaccine booster is influenced by differential splicing of HLA genes

Many molecular mechanisms that lead to the host antibody response to COVID-19 vaccines remain largely unknown. In this study, we used serum antibody detection combined with whole blood RNA-based transcriptome analysis to investigate variability in vaccine response in healthy recipients of a booster (third) dose schedule of the mRNA BNT162b2 vaccine against COVID-19. The cohort was divided into two groups: (1) low-stable individuals, with antibody concentration anti-SARS-CoV IgG S1 below 0.4 percentile at 180 days after boosting vaccination; and (2) high-stable individuals, with antibody values greater than 0.6 percentile of the range in the same period (median 9525 [185-80,000] AU/mL). Differential gene expression, expressed single nucleotide variants and insertions/deletions, differential splicing events, and allelic imbalance were explored to broaden our understanding of the immune response sustenance. Our analysis revealed a differential expression of genes with immunological functions in individuals with low antibody titers, compared to those with higher antibody titers, underscoring the fundamental importance of the innate immune response for boosting immunity. Our findings also provide new insights into the determinants of the immune response variability to the SARS-CoV-2 mRNA vaccine booster, highlighting the significance of differential splicing regulatory mechanisms, mainly concerning HLA alleles, in delineating vaccine immunogenicity.

The impact of underreported infections on vaccine effectiveness estimates derived from retrospective cohort studies

BACKGROUND

Surveillance data and vaccination registries are widely used to provide real-time vaccine effectiveness (VE) estimates, which can be biased due to underreported (i.e. under-ascertained and under-notified) infections. Here, we investigate how the magnitude and direction of this source of bias in retrospective cohort studies vary under different circumstances, including different levels of underreporting, heterogeneities in underreporting across vaccinated and unvaccinated, and different levels of pathogen circulation.

METHODS

We developed a stochastic individual-based model simulating the transmission dynamics of a respiratory virus and a large-scale vaccination campaign. Considering a baseline scenario with 22.5% yearly attack rate and 30% reporting ratio, we explored fourteen alternative scenarios, each modifying one or more baseline assumptions. Using synthetic individual-level surveillance data and vaccination registries produced by the model, we estimated the VE against documented infection taking as reference either unvaccinated or recently vaccinated individuals (within 14 days post-administration). Bias was quantified by comparing estimates to the known VE assumed in the model.

RESULTS

VE estimates were accurate when assuming homogeneous reporting ratios, even at low levels (10%), and moderate attack rates (<50%). A substantial downward bias in the estimation arose with homogeneous reporting and attack rates exceeding 50%. Mild heterogeneities in reporting ratios between vaccinated and unvaccinated strongly biased VE estimates, downward if cases in vaccinated were more likely to be reported and upward otherwise, particularly when taking as reference unvaccinated individuals.

CONCLUSIONS

In observational studies, high attack rates or differences in underreporting between vaccinated and unvaccinated may result in biased VE estimates. This study underscores the critical importance of monitoring data quality and understanding biases in observational studies, to more adequately inform public health decisions.

Antigenic cartography using hamster sera identifies SARS-CoV-2 JN.1 evasion seen in human XBB.1.5 booster sera

Antigenic assessments of SARS-CoV-2 variants inform decisions to update COVID-19 vaccines. Primary infection sera are often used for assessments, but such sera are rare due to population immunity from SARS-CoV-2 infections and COVID-19 vaccinations. Here, we show that neutralization titers and breadth of matched human and hamster pre-Omicron variant primary infection sera correlate well and generate similar antigenic maps. The hamster antigenic map shows modest antigenic drift among XBB sub-lineage variants, with JN.1 and BA.4/BA.5 variants within the XBB cluster, but with five to six-fold antigenic differences between these variants and XBB.1.5. Compared to sera following only ancestral or bivalent COVID-19 vaccinations, or with post-vaccination infections, XBB.1.5 booster sera had the broadest neutralization against XBB sub-lineage variants, although a five-fold titer difference was still observed between JN.1 and XBB.1.5 variants. These findings suggest that antibody coverage of antigenically divergent JN.1 could be improved with a matched vaccine antigen.

ChatGPT and Vaccines: Can AI Chatbots Boost Awareness and Uptake?

The global COVID-19 pandemic has affected all spheres of human life, resulting in millions of deaths and overwhelming medical facilities. Moreover, the world has witnessed great financial hardship because of job losses resulting in economic havoc. Many sections of society have contributed in different ways to slow the spread of the virus and protect public health. For example, medical scientists are praised for their efforts to develop COVID-19 vaccines. Clinical trials have shown that the COVID-19 vaccines are highly effective in preventing symptomatic COVID-19 infections. However, many people around the world have been hesitant to get vaccinated. Vaccine misconceptions have emerged and increased due to a combination of factors, including the availability of information on the Internet and the influence of celebrities and opinion leaders. In this context, we have analyzed ChatGPT responses to relevant queries on vaccine misconceptions. The positive responses and supportive opinions provided by the AI chatbot could be instrumental in shaping people's perceptions of vaccines and in encouraging users to get vaccinated and reduce misconceptions.

Understanding the role of risk preferences and perceptions in vaccination decisions and post-vaccination behaviors among U.S. households

COVID-19 vaccines play a critical role in protecting against infection and transmission of the virus. Therefore, understanding public perceptions of COVID-19 vaccines is essential for successful vaccine promotion. Previous literature reported strong associations between vaccination decisions and several sociodemographic variables. However, knowledge about how behavioral factors, including risk perceptions and preferences, impact individuals' attitudes towards receiving COVID-19 vaccination is currently lacking. Using data from a nationally representative survey of 1050 US adults, this study investigates the correlation between individuals' decisions to receive COVID-19 vaccination and both their risk perceptions and preferences. Additionally, we investigate post-vaccination behavior by measuring individuals' participation in three different groups of activities that vary by their degree of social exposure. We find strong correlations between vaccination decisions and four measures of risk preference and risk perception. We also find associations between the four risk measures and individuals' behaviors post-vaccination. We shed light on the main factors discouraging the uptake of COVID-19 vaccines, as well as public opinions regarding the performance of different organizations in addressing the COVID-19 pandemic, and grocery store policies to prevent COVID-19 infections. Our study provides critical information that can help policymakers communicate more effectively with the public and promote vaccine uptake among population groups and geographic areas with higher anti-vaccine sentiments.

Strategic Planning of a Joint SARS-CoV-2 and Influenza Vaccination Campaign in the UK

The simultaneous administration of SARS-CoV-2 and influenza vaccines is being carried out for the first time in the UK and around the globe in order to mitigate the health, economic, and societal impacts of these respiratory tract diseases. However, a systematic approach for planning the vaccine distribution and administration aspects of the vaccination campaigns would be beneficial. This work develops a novel multi-product mixed-integer linear programming (MILP) vaccine supply chain model that can be used to plan and optimise the simultaneous distribution and administration of SARS-CoV-2 and influenza vaccines. The outcomes from this study reveal that the total budget required to successfully accomplish the SARS-CoV-2 and influenza vaccination campaigns is equivalent to USD 7.29 billion, of which the procurement costs of SARS-CoV-2 and influenza vaccines correspond to USD 2.1 billion and USD 0.83 billion, respectively. The logistics cost is equivalent to USD 3.45 billion, and the costs of vaccinating individuals, quality control checks, and vaccine shipper and dry ice correspond to USD 1.66, 0.066, and 0.014, respectively. The analysis of the results shows that the choice of rolling out the SARS-CoV-2 vaccine during the vaccination campaign can have a significant impact not only on the total vaccination cost but also on vaccine wastage rate.

Expertise as a Response to Limited Multilateralism: The Case of South Korea's Vaccine Procurement Task Force for COVID-19 Vaccines amid Unequal Access via the COVAX Facility

This study investigates South Korea's trials and errors in procuring COVID-19 vaccines from abroad, amid the limitations of a multilateral scheme for global provision through the COVID-19 Vaccines Global Access (COVAX) program via the World Health Organization (WHO) and the discussions on COVID-19 vaccine patent waivers at the World Trade Organization. Using the framework of "self-help" in the international system and country categorization to explicate country behaviors by state-business relations and expertise to explain South Korea's COVID-19 vaccine procurement process, this study argues that in the absence of a global mechanism that guarantees adequate and timely vaccine provision, countries are left to the sole option of depending on their own capabilities: expertise, budget, and policy planning by consolidating public and private capacities to acquire vaccines for the public. To support the argument, an in-depth case investigation of South Korea's Vaccine Procurement Task Force is presented. The case study focuses on the policy assessment of critical elements in South Korea's vaccine procurement and rollout on facing obstacles to sufficient procurement through COVAX: decision-making impacting the timing and dosage of procurement, diplomatic and business channels to sign bilateral contracts, setup of a smart-factory vaccination hub, and indigenous vaccine development for WHO approval.

The effects of Chinese proprietary medicine and vaccination on patients with COVID-19: a retrospective study in Macao

BACKGROUND

COVID-19 is continuing to ravage globally and has resulted in a huge health and financial burden. Chinese proprietary medicines, such as Lianhua Qingwen (LHQW) and Huoxiang Zhengqi (HXZQ) capsules, have been recommended for non-high-risk patients with COVID-19 in China. Based on this, we described the baseline information, using status of LHQW and HXZQ capsules and inoculation history of quarantined patients in the second half of 2022 in Macao. Additionally, we analyzed the underlying association among medicines administration, vaccination and COVID-19 indices, in order to explore novel clues for the regular control and prevention of local epidemic situation in the future.

METHODS

A total of 976 patients in Macao quarantine hotels from June to August 2022 were included in the present study, of which, 857 subjects were followed-up for prognosis evaluation. During quarantine, the baseline demographic information, including sex, age, BMI, occupation and personal habits were collected. Additionally, the inoculation history, medicine employment status and cycle threshold (Ct) values were also reported. We interviewed the patients for collection of their symptoms at the beginning and end of quarantine, as well as prognostic ones. Basic statistical description of baseline information, vaccination history and medication were displayed. Chi-squared test or with continuous correction test was employed for comparison of dichotomous data between two or multiple groups. Binary logistic regression was applied to reveal the correlation between potential risk factors and Ct values or prognosis symptoms. We also used Cox regression model to identify the effect of different types of vaccine products on Ct value altering rate.

RESULTS

Patients who were female (52.0%), engaged in service industry (31.8%), from Macao native (65.8%), never took physical exercises (33.6%) and preferred irritated diet (59.5%) enjoyed more dominant proportions. Over 80% of participants were inoculated and 74.6% of them chose inactivated COVID-19 vaccine produced by China National Biotech Group (CNBG). Participants used LHQW capsules accounted for 92.1% and the duration of medicating lasted for one to two weeks. All of the reported symptoms were significantly ameliorated after quarantine and the duration of quarantine was concentrated on 21 days. People with different age, sex, occupation and region had different choices of HXZQ administration and vaccination. Additionally, middle dose (4-5 boxes) of LHQW capsules exhibited evidently negative association with positive Ct values (adjusted, - 0.037 ± 0.19, p = 0.04). Two doses of CNBG and one dose of mRNA vaccine had obvious protective effect on reducing Ct positive rate (p = 0.041). Meanwhile, symptoms after quarantine were significantly positive correlated with those in prognosis (adjusted, 1.38 ± 0.18, p < 0.0001).

CONCLUSION

Our study found that the administration of LHQW capsules was beneficial for Ct value turning negative, meanwhile, certain mixed inoculation may be the promoting factor to reduce the positive rate of Ct value. These findings provide data basis for the Chinese proprietary medicine treatment and mixed vaccination applying for prevention and control of local COVID-19 epidemic in the future.

Association between vaccination rates and COVID-19 health outcomes in the United States: a population-level statistical analysis

BACKGROUND

Population-level vaccine efficacy is a critical component of understanding COVID-19 risk, informing public health policy, and mitigating disease impacts. Unlike individual-level clinical trials, population-level analysis characterizes how well vaccines worked in the face of real-world challenges like emerging variants, differing mobility patterns, and policy changes.

METHODS

In this study, we analyze the association between time-dependent vaccination rates and COVID-19 health outcomes for 48 U.S. states. We primarily focus on case-hospitalization risk (CHR) as the outcome of interest, using it as a population-level proxy for disease burden on healthcare systems. Performing the analysis using Generalized Additive Models (GAMs) allowed us to incorporate real-world nonlinearities and control for critical dynamic (time-changing) and static (temporally constant) factors. Dynamic factors include testing rates, activity-related engagement levels in the population, underlying population immunity, and policy. Static factors incorporate comorbidities, social vulnerability, race, and state healthcare expenditures. We used SARS-CoV-2 genomic surveillance data to model the different COVID-19 variant-driven waves separately, and evaluate if there is a changing role of the potential drivers of health outcomes across waves.

RESULTS

Our study revealed a strong and statistically significant negative association between vaccine uptake and COVID-19 CHR across each variant wave, with boosters providing additional protection during the Omicron wave. Higher underlying population immunity is shown to be associated with reduced COVID-19 CHR. Additionally, more stringent government policies are generally associated with decreased CHR. However, the impact of activity-related engagement levels on COVID-19 health outcomes varied across different waves. Regarding static variables, the social vulnerability index consistently exhibits positive associations with CHR, while Medicaid spending per person consistently shows a negative association. However, the impacts of other static factors vary in magnitude and significance across different waves.

CONCLUSIONS

This study concludes that despite the emergence of new variants, vaccines remain highly correlated with reduced COVID-19 harm. Therefore, given the ongoing threat posed by COVID-19, vaccines remain a critical line of defense for protecting the public and reducing the burden on healthcare systems.

A Quantitative Clinical Pharmacology-Based Framework For Model-Informed Vaccine Development

Historically, vaccine development and dose optimization have followed mostly empirical approaches without clinical pharmacology and model-informed approaches playing a major role, in contrast to conventional drug development. This is attributed to the complex cascade of immunobiological mechanisms associated with vaccines and a lack of quantitative frameworks for extracting dose-exposure-efficacy-toxicity relationships. However, the Covid-19 pandemic highlighted the lack of sufficient immunogenicity due to suboptimal vaccine dosing regimens and the need for well-designed, model-informed clinical trials which enhance the probability of selection of optimal vaccine dosing regimens. In this perspective, we attempt to develop a quantitative clinical pharmacology-based approach that integrates vaccine dose-efficacy-toxicity across various stages of vaccine development into a unified framework that we term as model-informed vaccine dose-optimization and development (MIVD). We highlight scenarios where the adoption of MIVD approaches may have a strategic advantage compared to conventional practices for vaccines.

Perceptions of the COVID-19 Vaccination Within a Convenience Sample of Sudanese Americans

INTRODUCTION

Sudanese American and other immigrant and refugee communities are at greater risk for exposure to COVID-19. This survey sought to better characterize COVID-19 vaccination practices, motivators, and drivers for hesitancy among Sudanese Americans.

METHODS

We developed an online, cross-sectional survey in English and Arabic distributed by Sudanese American community leaders in April 2022 with data stored anonymously in REDCap. Inclusion criteria were self-reporting being born within Sudan and living in the US within the last 2 years. Descriptive analysis tested survey responses for possible associations between the primary outcome, self-reported vaccination status, and questions regarding vaccination history, perspectives on vaccination, and demographic characteristics using Fishers Exact and Chi Squared Tests.

RESULTS

Of 111 survey responses received, 107 met inclusion criteria. 93% of respondents reported COVID-19 vaccine uptake with the primary motivation to protect oneself from disease. The most cited reason for vaccine hesitancy was belief it had not been studied enough. The group that reported vaccination had higher levels of education (.032) and were more likely to perceive that COVID-19 vaccinations were able to reduce spread (.001), decrease severe outcomes (.004), and benefits outweighing their risks (.004).

DISCUSSION AND CONCLUSIONS

This survey population of Sudanese Americans demonstrated high levels of vaccine uptake (93%), far greater than either the corresponding US (78%) or Sudanese population (15%). It is likely that high levels of educational attainment moderated vaccine uptake, though our survey may not have had the power to fully evaluate vaccine hesitancy.

Global pandemic preparedness: learning from the COVID-19 vaccine development and distribution

INTRODUCTION

The COVID-19 pandemic catalyzed unprecedented vaccine innovation, revealing critical shortcomings in achieving equitable vaccine access and underscoring the need for a focused review of the lessons learned to inform future pandemic preparedness, with emphasis on vaccine delivery, equity, and challenges in LMICs.

AREAS COVERED

We critically analyzed the pandemic vaccine development and distribution journey and the operational mechanisms that facilitated these achievements. For this purpose, we primarily searched pandemic vaccine stakeholder websites, reports, and publications. The analysis extends beyond the scientific narrative to address the 'how' of the process while anchoring the discussion on equity and global health security as fundamental to preparing for future pandemics.

EXPERT OPINION

Drawing on the insights gained from the COVID-19 pandemic, we identify several key challenges requiring immediate attention to fortify preparedness for future pandemics. These are cultivating leadership in the field of vaccinology, guaranteeing equitable global access to diagnostics, therapeutic agents, and vaccines, securing adequate funding for ongoing research and development, ensuring the fair distribution of vaccines, and strategically allocating biomedical manufacturing facilities to ensure a balanced global production capacity. Addressing these challenges is imperative to establish a robust pandemic response framework and mitigate the impact of future global health crises.

How enlightened self-interest guided global vaccine sharing benefits all: A modeling study

Background

Despite consensus that vaccines play an important role in combatting the global spread of infectious diseases, vaccine inequity is still a prevalent issue due to a deep-seated mentality of self-priority. We aimed to evaluate the existence and possible outcomes of a more equitable global vaccine distribution and explore a concrete incentive mechanism that promotes vaccine equity.

Methods

We designed a metapopulation epidemiological model that simultaneously considers global vaccine distribution and human mobility, which we then calibrated by the number of infections and real-world vaccination records during the coronavirus disease 2019 (COVID-19) pandemic from March 2020 to July 2021. We explored the possibility of the enlightened self-interest incentive mechanism, which comprises improving one's own epidemic outcomes by sharing vaccines with other countries, by evaluating the number of infections and deaths under various vaccine sharing strategies using the proposed model. To understand how these strategies affect the national interests, we distinguished imported from local cases for further cost-benefit analyses that rationalise the enlightened self-interest incentive mechanism behind vaccine sharing.

Results

The proposed model accurately reproduces the real-world cumulative infections for both global and regional epidemics (R2>0.990), which can support the following evaluations of different vaccine sharing strategies: High-income countries can reduce 16.7 (95% confidence interval (CI) = 8.4-24.9, P < 0.001) million infection cases and 82.0 (95% CI = 76.6-87.4, P < 0.001) thousand deaths on average by more actively sharing vaccines in an enlightened self-interest manner, where the reduced internationally imported cases outweigh the threat from increased local infections. Such vaccine sharing strategies can also reduce 4.3 (95% CI = 1.2-7.5, P < 0.01) million infections and 7.0 (95% CI = 5.7-8.3, P < 0.001) thousand deaths in middle- and low-income countries, effectively benefiting the whole global population. Lastly, the more equitable vaccine distribution could help largely reduce the global mobility reduction needed for pandemic control.

Conclusions

The incentive mechanism of enlightened self-interest we explored here could motivate vaccine equity by realigning the national interest to more equitable vaccine distributions. The positive results could promote multilateral collaborations in global vaccine redistribution and reconcile conflicted national interests, which could in turn benefit the global population.

Predicting COVID-19 pandemic waves including vaccination data with deep learning

Introduction

During the recent COVID-19 pandemics, many models were developed to predict the number of new infections. After almost a year, models had also the challenge to include information about the waning effect of vaccines and by infection, and also how this effect start to disappear.

Methods

We present a deep learning-based approach to predict the number of daily COVID-19 cases in 30 countries, considering the non-pharmaceutical interventions (NPIs) applied in those countries and including vaccination data of the most used vaccines.

Results

We empirically validate the proposed approach for 4 months between January and April 2021, once vaccination was available and applied to the population and the COVID-19 variants were closer to the one considered for developing the vaccines. With the predictions of new cases, we can prescribe NPIs plans that present the best trade-off between the expected number of COVID-19 cases and the social and economic cost of applying such interventions.

Discussion

Whereas, mathematical models which include the effect of vaccines in the spread of the SARS-COV-2 pandemic are available, to the best of our knowledge we are the first to propose a data driven method based on recurrent neural networks that considers the waning effect of the immunization acquired either by vaccine administration or by recovering from the illness. This work contributes with an accurate, scalable, data-driven approach to modeling the pandemic curves of cases when vaccination data is available.

Previous Infection and Effectiveness of COVID-19 Vaccination in Middle- and High-School Students

BACKGROUND AND OBJECTIVES

Understanding the real-world impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mitigation measures, particularly vaccination, in children and adolescents in congregate settings remains important. We evaluated protection against SARS-CoV-2 infection using school-based testing data.

METHODS

Using data from Utah middle- and high-school students participating in school-wide antigen testing in January 2022 during omicron (BA.1) variant predominance, log binomial models were fit to estimate the protection of previous SARS-CoV-2 infection and coronavirus disease 2019 vaccination against SARS-CoV-2 infection.

RESULTS

Among 17 910 students, median age was 16 years (range: 12-19), 16.7% had documented previous SARS-CoV-2 infection; 55.6% received 2 vaccine doses with 211 median days since the second dose; and 8.6% of students aged 16 to 19 years received 3 vaccine doses with 21 median days since the third dose. Protection from previous infection alone was 35.9% (95% confidence interval [CI]: 12.9%-52.8%) and 23.8% (95% CI: 2.1%-40.7%) for students aged 12 to 15 and 16 to 19 years, respectively. Protection from 2-dose hybrid immunity (previous SARS-CoV-2 infection and vaccination) with <180 days since the second dose was 58.7% (95% CI: 33.2%-74.4%) for students aged 12 to 15 and 54.7% (95% CI: 31.0%-70.3%) for students aged 16 to 19 years. Protection was highest (70.0%, 95% CI: 42.3%-84.5%) among students with 3-dose hybrid immunity, although confidence intervals overlap with 2-dose vaccination.

CONCLUSIONS

The estimated protection against infection was strongest for those with hybrid immunity from previous infection and recent vaccination with a third dose.

Barriers and Motivators toward Childhood COVID-19 Vaccination: A Cross-Sectional Study Conducted among Saudi Population

Background and Objectives: In 2020, one of the most important steps that were made was to give priority to the development of a COVID-19 vaccine to prevent the rising incidence of COVID-19 from continuing to rise. However, globally, there is a variable acceptance of the level of the COVID-19 vaccine. This study aims to explore Saudi parents' willingness to vaccinate their children against COVID-19. Materials and Methods: This was a cross-sectional study; the online questionnaire was used to investigate the views of Saudi parents with children aged under 18 toward the immunization of their children against COVID-19. The data were gathered from 10 May 2022 to 31 October 2022. The data analysis uses SPSS version 20. A p-value of 0.05 or lower was regarded as statistically significant. Results: A total of 978 Saudi parents participated in this study. Most of the respondents were from the age group of 36-45 years with the educational qualification of high school and bachelor's degree. Overall, it was observed that the majority, 98.2% of the respondents, disclosed that they needed more information (p = 0.004) about COVID-19 vaccine safety among children so that they could decide whether to vaccinate their child. About 91.4% of parents mention that vaccination against COVID-19 is not necessary for children (p = 0.001). About 68.3% of respondents agreed that getting vaccinated against COVID-19 could help Saudi Arabia control COVID-19 (p = 0.007, RI = 0.76). In terms of negative attitudes toward COVID-19 vaccination, 71.3% think that there will be severe side effects (p = 0.019, RI = 0.75); 67.7% think that the vaccine's protection will only last for a short time (p = 0.055, RI = 0.72); 80.1% said they were afraid of getting vaccinated because of needle fear (p = 0.045, RI = 0.76), and 41.2% said lack of time was the main barrier to not vaccinating their child. Conclusions: Parents expressed concerns regarding the safety and efficacy of the COVID-19 vaccine, which might be some of the main factors influencing their decision to vaccinate their children. It is the need of the hour to take action to communicate, educate, and intervene with Saudi parents to enhance COVID-19 vaccination compliance rates across the board.

Primate field research during a pandemic: Lessons learned from the SARS-CoV-2 outbreak

The COVID-19 pandemic abruptly halted most primate field research in early 2020. While international travel bans and regional travel restrictions made continuing primate field research impossible early on in the pandemic, ethical concerns of transmitting the virus from researchers to primates and surrounding human communities informed decisions regarding the timing of resuming research. Between June and September 2020, we surveyed field primatologists regarding the impacts of the pandemic on their research. We received 90 completed surveys from respondents residing in 21 countries, though most were from the United States and Canada. These data provide a valuable window into the perspectives and actions taken by researchers during the early stages of the pandemic as events were still unfolding. Only 2.4% of projects reported continuing research as usual, 33.7% continued with some decrease in productivity, 42.2% reported postponing research projects, and 21.7% reported canceling projects or postponing research indefinitely. Respondents most severely impacted by the pandemic were those establishing new field sites and graduate students whose projects were postponed or canceled due to pandemic-related shutdowns. Fears about increased poaching, the inability to pay local assistants, frozen research funds, declining habituation, disruptions to data collection, and delays in student projects were among the top concerns of respondents. Nearly all the projects able to continue research in any capacity during the early months of the pandemic were run by or employed primate habitat country primatologists. This finding is a major lesson learned from the pandemic; without habitat country scientists, primate research is not sustainable.

Combination Organelle Mitochondrial Endoplasmic Reticulum Therapy (COMET) for Multidrug Resistant Breast Cancer

It is time for the story of mitochondria and intracellular communication in multidrug resistant cancer to be rewritten. Herein we characterize the extent and cellular advantages of mitochondrial network fusion in multidrug resistant (MDR) breast cancer and have designed a novel nanomedicine that disrupts mitochondrial network fusion and systematically manipulates organelle fusion and function. Combination Organelle Mitochondrial Endoplasmic reticulum Therapy (COMET) is an innovative translational nanomedicine for treating MDR triple negative breast cancer (TNBC) that has superior safety and equivalent efficacy to the current standard of care (paclitaxel). Our study has demonstrated that the increased mitochondrial networks in MDR TNBC contribute to apoptotic resistance and network fusion is mediated by mitofusin2 (MFN2) on the outer mitochondrial membrane. COMET consists of three components; Mitochondrial Network Disrupting (MiND) nanoparticles (NPs) that are loaded with an anti-MFN2 peptide, tunicamycin, and Bam7. The therapeutic rationale of COMET is to reduce the apoptotic threshold in MDR cells with MiND NPs, followed by inducing the endoplasmic reticulum mediated unfolded protein response (UPR) by stressing MDR cells with tunicamycin, and finally, directly inducing mitochondrial apoptosis with Bam7 which is a specific bcl-2 Bax activator. MiND NPs are PEGylated liposomes with the 21 amino acid (2577.98 MW) anti-MFN2 peptide compartmentalized in the aqueous core. Hypoxia (0.5% oxygen) was used to create MDR derivatives of MDA-MB-231 cells and BT-549 cells. Mitochondrial networks were quantified using 3D analysis of 60× live cell images acquired with a Keyence BZ-X710 microscope and MiND NPs effectively fragmented mitochondrial networks in drug sensitive and MDR TNBC cells. The IC50 values, combination index, and dose reduction index derived from dose response studies demonstrate that MiND NPs decrease the apoptotic threshold of both drug sensitive and MDR TNBC cells and COMET is a synergistic drug combination. Complex V (ATP synthase) extracted from bovine cardiac mitochondria was used to assess the effect of MiND NPs on OXPHOS; both MiND NPs and anti-MFN2 peptide solution significantly decrease the activity of mitochondrial complex V and decrease the capacity of OXPHOS. A BacMam viral vector based fluorescent biosensor was used to quantify the unfolded protein response (UPR) at the level of the endoplasmic reticulum and tunicamycin specifically induces the UPR in drug sensitive and MDR TNBC cells. A caspase 3 colorimetric assay demonstrated that the synergistic triple drug combination of COMET increases the ability of Bam7 to specifically induce apoptosis. Dose limiting toxicity and off target effects are a significant challenge for current chemotherapy regimens including paclitaxel. COMET has significantly lower cytotoxicity than paclitaxel in human embryonic kidney epithelial cells and has the potential to fulfill the clinical need for safer cancer therapeutics. COMET is a promising early stage translational nanomedicine for treating MDR TNBC. Manipulating intracellular communication and organelle fusion is a novel approach to treating MDR cancer. The data from this study has rewritten the story of mitochondria, organelle fusion, and intracellular communication and by targeting this intersection, COMET is an exciting new chapter in cancer therapeutics that could transform the clinical outcome of MDR TNBC.

Acceptance of COVID-19 vaccine booster dose among the people of Bangladesh: A cross-sectional study

Vaccine booster dose (VBD) provides a potential therapeutic alliance in preventing breakthrough infection and new variant's arrival while preserving long-lasting host immunity. This study aimed to analyze COVID-19 VBD willingness and identified the key determinants of VBD acceptance among the general people of Bangladesh. This survey-based study applied a quantitative research paradigm. A validated, anonymous, and multi-item questionnaire was adopted through a theoretical review of pertinent literature on the topic. Data were collected between August 2022─October 2022, and sampling was done randomly. A total of 704 individuals were invited via face-to-face interview approach; however, 13.8 % of them declined to give consent, which resulted in the participation of 607 potential respondents. The main outcome measure was COVID-19 VBD acceptance willingness. Binary logistic regression analysis was conducted to rationalize the study's objectives. The pooled COVID-19 booster vaccine acceptance rate was 70.0 % (95 % confidence Interval [CI]: 67─73) among Bangladeshi people. An analysis of binary logistic regression revealed that, out of 14 potential factors, "efficacy", "repeated immunity", "communication", and "trust" showed highly significant positive association (adjusted odds ratio [aOR ] = 2.151 95 % CI: 1.391─ 3.508, aOR = 2.033 95 % CI: 1.299─ 3.181, and aOR = 2.552 95 % CI: 1.557─4.183 respectively, p<0.01), and "equal safety", "risk-benefit ratio" and "community protection" had significant positive association (aOR = 1.739 95 % CI: 1.070─2.825, aOR = 1.712 95 % CI: 1.116─2.627, and aOR = 1.628 95 % CI: 1.395─0.998, p<0.05) with VBD acceptance. However, post-vaccination "side effects" showed significant negative (aOR = 0.393 95 % CI: 0.237─0.674, p<0.01) associations with VBD acceptance. The odds of accepting the COVID-19 vaccine booster was found 1.26, and it was found insignificant (p>0.05) in the Chi-squared test. Bangladeshi people expressed a moderately high level response to COVID-19 VBD acceptance. A positive attitude towards the COVID-19 VBD is an outcome of this study, regardless of the circumstances, as far as safety, efficacy, perceived health benefits, communication, trust, and community resistance are concerned. Post-vaccination side effects fear was the primary reason for booster dose skepticism as well as a barrier to administering booster shots. The confidence in COVID-19 VBD will be boosted when mass people are effectively communicated and vaccine's data become more available publicly.

Macro1 domain residue F156: A hallmark of SARS-CoV-2 de-MARylation specificity

SARS-CoV-2 is a large, enveloped and positive sense single stranded RNA virus. Its genome codes for 16 non-structural proteins. The largest protein of this complex is nsp3, that contains a well conserved Macro1 domain. Viral Macro domains were shown to bind to mono-ADP-ribose (MAR) and poly-ADP-ribose (PAR) in their free form or conjugated to protein substrates. They carry ADP-ribose hydrolase activities implicated in the regulation of innate immunity. SARS-CoV-2 and SARS-CoV show widely different induction and handling of the host interferon response. Herein, we have conducted a mutational study on the key amino-acid residue F156 in SARS-CoV-2, pinpointed by bioinformatic and structural studies, and its cognate residue N157 in SARS-CoV. Our data suggest that the exchange of these residues slightly modifies ADP-ribose binding, but drastically impacts de-MARylation activity. Alanine substitutions at this position hampers PAR binding, abolishes MAR hydrolysis of SARS-CoV-2, and reduces by 70% this activity in the case of SARS-CoV.

Immunogenicity and Pre-Clinical Efficacy of an OMV-Based SARS-CoV-2 Vaccine

The vaccination campaign against SARS-CoV-2 relies on the world-wide availability of effective vaccines, with a potential need of 20 billion vaccine doses to fully vaccinate the world population. To reach this goal, the manufacturing and logistic processes should be affordable to all countries, irrespective of economical and climatic conditions. Outer membrane vesicles (OMVs) are bacterial-derived vesicles that can be engineered to incorporate heterologous antigens. Given the inherent adjuvanticity, such modified OMVs can be used as vaccines to induce potent immune responses against the associated proteins. Here, we show that OMVs engineered to incorporate peptides derived from the receptor binding motif (RBM) of the spike protein from SARS-CoV-2 elicit an effective immune response in vaccinated mice, resulting in the production of neutralizing antibodies (nAbs) with a titre higher than 1:300. The immunity induced by the vaccine is sufficient to protect the animals from intranasal challenge with SARS-CoV-2, preventing both virus replication in the lungs and the pathology associated with virus infection. Furthermore, we show that OMVs can be effectively decorated with the RBM of the Omicron BA.1 variant and that such engineered OMVs induce nAbs against Omicron BA.1 and BA.5, as measured using the pseudovirus neutralization infectivity assay. Importantly, we show that the RBM438-509 ancestral-OMVs elicited antibodies which efficiently neutralize in vitro both the homologous ancestral strain, the Omicron BA.1 and BA.5 variants with a neutralization titre ranging from 1:100 to 1:1500, suggesting its potential use as a vaccine targeting diverse SARS-CoV-2 variants. Altogether, given the convenience associated with the ease of engineering, production and distribution, our results demonstrate that OMV-based SARS-CoV-2 vaccines can be a crucial addition to the vaccines currently available.

Efficacy and safety of an inactivated virus-particle vaccine for SARS-CoV-2, BIV1-CovIran: randomised, placebo controlled, double blind, multicentre, phase 3 clinical trial

OBJECTIVE

To report the efficacy, safety, and exploratory immunogenicity findings of two 5 µg doses of the BIV1-CovIran vaccine.

DESIGN

Randomised, placebo controlled, double blind, multicentre, phase 3 clinical trial.

SETTING

In six cities of Iran, including Bushehr, Isfahan, Karaj, Mashhad, Shiraz, and Tehran. The first vaccine or placebo injection of the first participant was on 16 May 2021 in Tehran. The last vaccine or placebo injection of the last participant occurred on 15 July 2021 in Isfahan.

PARTICIPANTS

20 000 participants aged 18-75 years were randomly assigned to the intervention or placebo groups with a ratio of 2:1.

INTERVENTION

5 µg vaccine or placebo with the interval of 28 days.

MAIN OUTCOME MEASURES

Vaccine efficacy for a 90 day follow-up period, safety and explanatory immunogenicity assessment, and variant detection during the trial.

RESULTS

20 000 participants were recruited and randomly assigned to receive BIV1-CovIran (n=13 335 (66.7%)) or placebo (n=6665 (33.3%)). Participants' mean age was 38.3 (standard deviation 11.2) years, and 6913 (34.6%) were female. Among vaccinated participants that had covid-19 reported during the follow-up (median 83 days), 758 (5.9%) had symptoms, 144 (1.1%) had severe infection, and seven (0.1%) were critical. Among participants who received placebo during the follow-up, 688 (10.7%) had symptoms, 221 (3.4%) had severe infection, and 19 (0.3%) were critical. Overall efficacy was 50.2% (95% confidence interval 44.7% to 55.0%) against symptomatic covid-19, 70.5% (63.7% to 76.1%) against severe disease, and 83.1% (61.2% to 93.5%) against critical cases. Two deaths were reported in the efficacy population in the placebo group, no deaths were from the intervention group. During follow-up, 41 922 adverse events were reported: 28 782 (68.7%) were adverse reactions, of which 19 363 (67.3%) were in the intervention group. Most adverse reactions were mild or moderate in severity (grade 1 or 2) and self-limiting. No serious adverse events were related to the injections. For variant investigation, of 119 participants positive for the SARS-CoV-2 variant, 106 (89.1%) were positive for the delta variant.

CONCLUSIONS

A two dose regimen of the BIV1-CovIran vaccine conferred efficacy of 50.2% against symptomatic covid-19, 70.5% against severe disease, and 83.1% against critical disease. Vaccination was well tolerated, with no safety concerns raised.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT20201202049567N3.

FUNDING

Shifa-Pharmed Industrial Group.

Comparative Safety and Effectiveness of Heterologous CoronaVac-ChAdOx1 versus Homologous CoronaVac Vaccination in a Real-World Setting: A Retrospective Cohort Study

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has outpaced vaccine availability and delivery from vaccine manufacturers, and thus, a scarcity of vaccines happened to many countries around the world. In Thailand, the mixing of different types of vaccines was approved and clinically implemented partially due to concerns about the availability and efficacy of one vaccine. Objective: This study aimed to investigate the effectiveness and safety of heterologous CoronaVac-ChAdOx1 nCoV-19 vaccines compared with the usual regimen of homologous CoronaVac-CoronaVac. A retrospective cohort study was conducted by dividing patients into the CoronaVac-CoronaVac group and the CoronaVac-ChAdOx1 group. Results: A total of 875 patients received vaccinations at Srisangwan Hospital between April to October 2021 and were included for analysis. The patients in both homologous and heterologous groups had low rates of COVID-19 infection. In addition, the hospitalization rates in the 40 days after the second vaccination were low in both regimens. Minimal adverse events (AE) were reported in both groups, including local AE (e.g., discomfort at the injection site, rash, soreness, swelling, and redness) and systemic AE (e.g., fever, headache, weariness, nausea, vomiting, diarrhoea, and myalgia). Moreover, several factors were associated with lower adverse events following immunization (AEFIs), including age ≥ 50 years, male, and body weight ≥ 50 kg. In contrast, thyroid disease, diabetes mellitus, allergic rhinitis, and psychiatric disorders were independent risk factors associated with an increase in AEFIs. Conclusions: The heterologous CoronaVac-ChAdOx1 and homologous CoronaVac-CoronaVac regimens were promising vaccination strategies for the prevention of SARS-CoV-2 infection. However, the heterologous CoronaVac-ChAdOx1 potentially caused fewer AEFIs compared with the homologous CoronaVac-CoronaVac regimen.

Dynamical modelling of viral infection and cooperative immune protection in COVID-19 patients

Once challenged by the SARS-CoV-2 virus, the human host immune system triggers a dynamic process against infection. We constructed a mathematical model to describe host innate and adaptive immune response to viral challenge. Based on the dynamic properties of viral load and immune response, we classified the resulting dynamics into four modes, reflecting increasing severity of COVID-19 disease. We found the numerical product of immune system's ability to clear the virus and to kill the infected cells, namely immune efficacy, to be predictive of disease severity. We also investigated vaccine-induced protection against SARS-CoV-2 infection. Results suggested that immune efficacy based on memory T cells and neutralizing antibody titers could be used to predict population vaccine protection rates. Finally, we analyzed infection dynamics of SARS-CoV-2 variants within the construct of our mathematical model. Overall, our results provide a systematic framework for understanding the dynamics of host response upon challenge by SARS-CoV-2 infection, and this framework can be used to predict vaccine protection and perform clinical diagnosis.

Studying temporal titre evolution of commercial SARS-CoV-2 assays reveals significant shortcomings of using BAU standardization for comparison

BACKGROUND

Measuring specific anti-SARS-CoV-2 antibodies has become one of the main epidemiological tools to survey the ongoing SARS-CoV-2 pandemic, but also vaccination response. The WHO made available a set of well-characterized samples derived from recovered individuals to allow normalization between different quantitative anti-Spike assays to defined Binding Antibody Units (BAU).

METHODS

To assess sero-responses longitudinally, a cohort of ninety-nine SARS-CoV-2 RT-PCR positive subjects was followed up together with forty-five vaccinees without previous infection but with two vaccinations. Sero-responses were evaluated using a total of six different assays: four measuring anti-Spike proteins (converted to BAU), one measuring anti-Nucleocapsid proteins and one SARS-CoV-2 surrogate virus neutralization. Both cohorts were evaluated using the Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and the Roche Elecsys Anti-SARS-CoV-2 anti-S1 assay.

RESULTS

In SARS-CoV-2-convalesce subjects, the BAU-sero-responses of Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and Roche Elecsys Anti-SARS-CoV-2 anti-S1 peaked both at 47 (43-51) days, the first assay followed by a slow decay thereafter (> 208 days), while the second assay not presenting any decay within one year. Both assay values in BAUs are only equivalent a few months after infection, elsewhere correction factors up to 10 are necessary. In contrast, in infection-naive vaccinees the assays perform similarly.

CONCLUSION

The results of our study suggest that the establishment of a protective correlate or vaccination booster recommendation based on different assays, although BAU-standardised, is still challenging. At the moment the characteristics of the available assays used are not related, and the BAU-standardisation is unable to correct for that.

Humoral and Cellular Immune Response Elicited by Two Doses of mRNA BNT162b2 Vaccine Against SARS-CoV-2 in People Living with HIV

At present, whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines can elicit robust humoral and cellular immune responses in people living with HIV (PLWH) is still controversial. We assessed humoral and cellular immune response after the administration of the BNT162b2-mRNA-vaccine in seven antiretroviral therapy-treated PLWH patients and in nine HIV-negative health care workers (PWOH) over a 3-month span of time from the first vaccine dose. The neutralizing activity against both the European and the Delta variants declined after 3 months equally in both PLWH and PWOH. The gene expression analysis of factors involved in the antiviral immune response did not show any significant difference between PLWH and PWOH; among circulating cytokines/chemokines, a progressive decline was observed in the mean values of IL-1β, IL-5, IL-6, IL-13, and IL-15 in both PLWH and PWOH. Conversely, the ratio between naive and terminally differentiated T-CD4+ effector memory showed a reduction trend over time in PLWH. Our findings showed no significant differences in the ability to mount an immune response after the administration of two SARS-CoV-2 mRNA BNT162b2 doses in PLWH and PWOH. However, as BNT162b2 vaccinated PLWH display an early waning immunity in the T cell compartment, the administration of a booster dose may be necessary to maintain a SARS-CoV-2-specific immune response.

Toxicity of the spike protein of COVID-19 is a redox shift phenomenon: A novel therapeutic approach

We previously demonstrated that most diseases display a form of anabolism due to mitochondrial impairment: in cancer, a daughter cell is formed; in Alzheimer's disease, amyloid plaques; in inflammation cytokines and lymphokines. The infection by Covid-19 follows a similar pattern. Long-term effects include redox shift and cellular anabolism as a result of the Warburg effect and mitochondrial dysfunction. This unrelenting anabolism leads to the cytokine storm, chronic fatigue, chronic inflammation or neurodegenerative diseases. Drugs such as Lipoic acid and Methylene Blue have been shown to enhance the mitochondrial activity, relieve the Warburg effect and increase catabolism. Similarly, coMeBining Methylene Blue, Chlorine dioxide and Lipoic acid may help reduce long-term Covid-19 effects by stimulating the catabolism.

Structural and Synthetic Aspects of Small Ring Oxa- and Aza-Heterocyclic Ring Systems as Antiviral Activities

Antiviral properties of different oxa- and aza-heterocycles are identified and properly correlated with their structural features and discussed in this review article. The primary objective is to explore the activity of such ring systems as antiviral agents, as well as their synthetic routes and biological significance. Eventually, the structure-activity relationship (SAR) of the heterocyclic compounds, along with their salient characteristics are exhibited to build a suitable platform for medicinal chemists and biotechnologists. The synergistic conclusions are extremely important for the introduction of a newer tool for the future drug discovery program.

Vaccination, human mobility, and COVID-19 health outcomes: Empirical comparison before and during the outbreak of SARS-Cov-2 B.1.1.529 (Omicron) variant

The B.1.1.529 (Omicron) variant surge has raised concerns about the effectiveness of vaccines and the impact of imprudent reopening. Leveraging over two years of county-level COVID-19 data in the US, this study aims to investigate relationships among vaccination, human mobility, and COVID-19 health outcomes (assessed via case rate and case-fatality rate), controlling for socioeconomic, demographic, racial/ethnic, and partisan factors. A set of cross-sectional models was first fitted to empirically compare disparities in COVID-19 health outcomes before and during the Omicron surge. Then, time-varying mediation analyses were employed to delineate how the effects of vaccine and mobility on COVID-19 health outcomes vary over time. Results showed that vaccine effectiveness against case rate lost significance during the Omicron surge, while its effectiveness against case-fatality rate remained significant throughout the pandemic. We also documented salient structural inequalities in COVID-19-related outcomes, with disadvantaged populations consistently bearing a larger brunt of case and death tolls, regardless of high vaccination rates. Last, findings revealed that mobility presented a significantly positive relationship with case rates during each wave of variant outbreak. Mobility substantially mediated the direct effect from vaccination to case rate, leading to a 10.276 % (95 % CI: 6.257, 14.294) decrease in vaccine effectiveness on average. Altogether, our study implies that sole reliance on vaccination to halt COVID-19 needs to be re-examined. Well-resourced and coordinated efforts to enhance vaccine effectiveness, mitigate health disparity and selectively loosen non-pharmaceutical interventions are essential to bringing the pandemic to an end.

Humoral and cellular immunity in three different types of COVID-19 vaccines against SARS-CoV-2 variants in a real-world data analysis

BACKGROUND

An effective vaccine response is currently a critical issue in the control of COVID-19. Little is known about humoral and cellular immunity comparing protein-based vaccine with other types of vaccines. The relevance of basal immunity to antibody production is also unknown.

METHODS

Seventy-eight individuals were enrolled in the study. The primary outcome were the level of spike-specific antibodies and neutralizing antibodies measured by ELISA. Secondary measures included memory T cells and basal immunity estimated by flow cytometry and ELISA. Correlations for all parameters were calculated using the nonparametric Spearman correlation method.

RESULTS

We observed that two doses of mRNA-based Moderna mRNA-1273 (Moderna) vaccine produced the highest total spike-binding antibody and neutralizing ability against the wild-type (WT), Delta, and Omicron variants. The protein-based MVC-COV1901 (MVC) vaccine developed in Taiwan produced higher spike-binding antibodies against Delta and Omicron variants and neutralizing ability against the WT strain than the adenovirus-based AstraZeneca-Oxford AZD1222 (AZ) vaccine. Moderna and AZ vaccination produced more central memory T cells in PBMC than the MVC vaccine. However, the MVC vaccine had the lowest adverse effects compared to the Moderna and AZ vaccines. Surprisingly, the basal immunity represented by TNF-α, IFN-γ, and IL-2 prior to vaccination was negatively correlated with the production of spike-binding antibodies and neutralizing ability.

CONCLUSION

This study compared memory T cells, total spike-binding antibody levels, and neutralizing capacity against WT, Delta, and Omicron variants between the MVC vaccine and the widely used Moderna and AZ vaccines, which provides valuable information for future vaccine development strategies.

Discovery of Hybrid Thiouracil-Coumarin Conjugates as Potential Novel Anti-SARS-CoV-2 Agents Targeting the Virus's Polymerase "RdRp" as a Confirmed Interacting Biomolecule

The coronavirus (COVID-19) pandemic, along with its various strains, has emerged as a global health crisis that has severely affected humankind and posed a great challenge to the public health system of affected countries. The replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly depends on RNA-dependent RNA polymerase (RdRp), a key enzyme that is involved in RNA synthesis. In this regard, we designed, synthesized, and characterized hybrid thiouracil and coumarin conjugates (HTCAs) by ether linkage, which were found to have anti-SARS-CoV-2 properties. Our in vitro real-time quantitative reverse transcription PCR (RT-qPCR) results confirmed that compounds such as 5d, 5e, 5f, and 5i inhibited the replication of SARS-CoV-2 with EC50 values of 14.3 ± 0.14, 6.59 ± 0.28, 86.3 ± 1.45, and 124 ± 2.38 μM, respectively. Also, compound 5d displayed significant antiviral activity against human coronavirus 229E (HCoV-229E). In addition, some of the HTCAs reduced the replication of SARS-CoV-2 variants such as D614G and B.617.2. In parallel, HTCAs in uninfected Vero CCL-81 cells indicated that no cytotoxicity was noticed. Furthermore, we compared the in silico interaction of lead compounds 5d and 5e toward the cocrystal structure of Suramin and RdRp polymerase with Remdesvir triphosphate, which showed that compounds 5d, 5e, and Remdesvir triphosphate (RTP) share a common catalytical site of RdRp but not Suramin. Additionally, the in silico ADMET properties predicted for the lead HTCAs and RTP showed that the maximum therapeutic doses recommended for compounds 5d and 5e were comparable to those of RTP. Concurrently, the pharmacokinetics of 5d was characterized in male Wistar Albino rats by administering a single oral gavage at a dose of 10 mg/kg, which gave a Cmax value of 0.22 μg/mL and a terminal elimination half-life period of 73.30 h. In conclusion, we established a new chemical entity that acts as a SARS-CoV-2 viral inhibitor with minimal or no toxicity to host cells in the rodent model, encouraging us to proceed with preclinical studies.

Public opinion on COVID-19 vaccine prioritization in Bangladesh: Who gets the vaccine and whom do you leave out?

One of the most challenging aspects of the COVID-19 pandemic is the inability to ensure equitable distribution of vaccines to fight the pandemic. Many governments around the globe had to prioritize and perform a triage in distributing the vaccines due to the limited supply as well as a lack of financial strength to acquire a sufficient number of vaccines in time. The present study assessed the public opinion in Bangladesh regarding vaccination prioritization strategy and its associated aspects. Due to the infectious nature of the viral transmission, the study used an online survey and collected a sample of 2291 respondents, distributed proportionally across sex, and income groups. Descriptive statistics and multinomial logistic regression modelling were utilized to conduct the analyses. The results emphasized unanimous preference of prioritized vaccination leaning towards the frontline workers, the severely sick and the elderly. However, the segregation across ethnicity was noted with no major preference among sexes or religion. The results reinforce the Bangladesh government's undertaken strategy of prioritization. However, the preference rankings varied across sociodemographic factors including self-assessed COVID-19 knowledge and income tiers, among others. The findings underline the necessity of improved risk communication strategies to ensure public confidence and conformity to vaccination efforts and their effective deployment across the country.

A Single Oral Immunization with a Replication-Competent Adenovirus-Vectored Vaccine Protects Mice from Influenza Respiratory Infection

The development of effective and flexible vaccine platforms is a major public health challenge, especially in the context of influenza vaccines that have to be renewed every year. Adenoviruses (AdVs) are easy to produce and have a good safety and efficacy profile when administered orally, as demonstrated by the long-term use of oral AdV-4 and -7 vaccines in the U.S. military. These viruses therefore appear to be the ideal backbone for the development of oral replicating vector vaccines. However, research into these vaccines is limited by the ineffectiveness of human AdV replication in laboratory animals. The use of mouse AdV type 1 (MAV-1) in its natural host allows infection to be studied under replicating conditions. Here, we orally vaccinated mice with a MAV-1 vector expressing influenza hemagglutinin (HA) to assess the protection conferred against an intranasal challenge of influenza. We showed that a single oral immunization with this vaccine generates influenza-specific and -neutralizing antibodies and completely protects mice against clinical signs and viral replication, similar to traditional inactivated vaccines. IMPORTANCE Given the constant threat of pandemics and the need for annual vaccination against influenza and possibly emerging agents such as SARS-CoV-2, new types of vaccines that are easier to administer and therefore more widely accepted are a critical public health need. Here, using a relevant animal model, we have shown that replicative oral AdV vaccine vectors can help make vaccination against major respiratory diseases more available, better accepted, and therefore more effective. These results could be of major importance in the coming years in the fight against seasonal or emerging respiratory diseases such as COVID-19.

Direct indicators of social distancing effectiveness in COVID-19 outbreak stages: a correlational analysis of case contacts and population mobility in Korea

OBJECTIVES

The effectiveness of social distancing during the coronavirus disease 2019 (COVID-19) pandemic has been evaluated using the magnitude of changes in population mobility. This study aimed to investigate a direct indicator-namely, the number of close contacts per patient with confirmed COVID-19.

METHODS

From week 7, 2020 to week 43, 2021, population movement changes were calculated from the data of two Korean telecommunication companies and Google in accordance with social distancing stringency levels. Data on confirmed cases and their close contacts among residents of Gyeonggi Province, Korea were combined at each stage. Pearson correlation analysis was conducted to compare the movement data with the change in the number of contacts for each confirmed case calculated by stratification according to age group. The reference value of the population movement data was set using the value before mid-February 2020, considering each data's characteristics.

RESULTS

In the age group of 18 or younger, the number of close contacts per confirmed case decreased or increased when the stringency level was strengthened or relaxed, respectively. In adults, the correlation was relatively low, with no correlation between the change in the number of close contacts per confirmed case and the change in population movement after the commencement of vaccination for adults.

CONCLUSIONS

The effectiveness of governmental social distancing policies against COVID-19 can be evaluated using the number of close contacts per confirmed case as a direct indicator, especially for each age group. Such an analysis can facilitate policy changes for specific groups.

Incidence of Bell's palsy after Coronavirus disease (COVID-19) vaccination: a systematic review and meta-analysis

OBJECTIVE

To estimate the pooled incidence of Bell's palsy after COVID-19 vaccination.

METHODS

PubMed, Scopus, EMBASE, Web of Science, and google scholar were searched by two independent researchers. We also searched gray literature including references of the references and conference abstracts. We extracted data regarding the total number of participants, first author, publication year, the country of origin, female/male, type of vaccines, and the number of patients who developed Bell's palsy after COVID-19 vaccination.

RESULTS

Literature search revealed 370 articles, subsequently deleting duplicates 227 remained. After careful evaluation of the full texts, twenty articles remained for meta-analysis. The most commonly administered vaccines were Pfizer followed by Moderna. In total, 4.54e+07 individuals received vaccines against COVID-19, and 1739 cases developed Bell's palsy. In nine studies, controls (individuals without vaccination) were enrolled. The total number of controls was 1809069, of whom, 203 developed Bell's palsy. The incidence of Bell's palsy after COVID-19 vaccines was ignorable. The odds of developing Bell's palsy after COVID-19 vaccines was 1.02 (95%CI: 0.79-1.32) (I2 = 74.8%, p < 0.001).

CONCLUSION

The results of this systematic review and meta-analysis show that the incidence of peripheral facial palsy after COVID-19 vaccination is ignorable and vaccination does not increase the risk of developing Bell's palsy. Maybe, Bell's palsy is a presenting symptom of a more severe form of COVID-19, so clinicians must be aware of this.

Evaluation of humoral immune response after ChAdOx1 nCoV-19 vaccination among health care workers

We assessed the immunogenicity of ChAdOx1 nCoV-19 vaccination by evaluating the levels of SARS-CoV-2 IgG after vaccination and investigated the effect of diverse factors such as gender, age, and adverse reactions after vaccination. The study included a total of 1028 serum samples from 452 healthcare workers. SARS-CoV-2 IgG levels were assessed using the SARS-CoV-2 IgG II Quant assay. Participants completed a questionnaire regarding the intensity and duration of adverse reactions after vaccination. The seropositive rates after the first and second doses were 95.5% and 100%, respectively. The median antibody levels after the second dose showed a 4.2-fold increase compared with the first. Five months after the second dose, the median antibody levels decreased by 3.5-fold. The antibody levels in men were lower than those in women after the first dose and were higher after the second dose. There was no difference according to age groups after the first dose, but after the second dose, in subjects aged 50 and above, the rise in antibody levels was less than that in other age groups. The antibody levels among participants with moderate or severe symptoms were significantly higher than those among participants with mild symptoms after the first dose. There were no statistically significant differences according to the duration of symptoms. We could assume that different age groups and genders might have different immunogenicity following vaccination. The intensity of adverse symptoms was positively correlated with the antibody levels, implying that higher immunogenicity is related to the intensity of adverse symptoms after vaccination.

Nanoadjuvants Produced by Advanced Nanochelating Technology in the Inactivated-Severe Acute Respiratory Syndrome Coronavirus-2 Vaccine Formulation: Preliminary Results on Cytokines and IgG Responses

Despite the great success of vaccines in various infectious diseases, most current vaccines are not effective enough, and on the contrary, clinically approved alum adjuvants cannot induce sufficient immune responses, including a potent cellular immune response to confer protection. In this study, we used Nanochelating Technology to develop novel nanoadjuvants to boost the potency of the alum-adjuvanted inactivated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine. BALB/c mice were immunized twice over 2 weeks with different doses of adjuvanted-vaccine formulations and immune responses were assessed. The analysis results of IFN-γ and IL-17 cytokines demonstrated the effectiveness of the nanoadjuvants produced by the Nanochelating Technology in shifting the alum-based vaccine toward a stronger Th1 pattern. In addition, these nanoadjuvants improved IL-2 cytokine response, which shows the efficacy of these novel formulations in inducing specific T lymphocyte proliferation. Using these nanoadjuvants increased IL-10 cytokine secretion that may be representative of a better immunoregulatory impact and may also potentially prevent immunopathology responses. Moreover, specific IgG titer analysis revealed the potency of these nanoadjuvants in improving humoral immune responses. The enzyme-linked immunosorbent assay of receptor-binding domain (RBD)-specific IgG response showed that the developed novel formulations induced strong IgG responses against this protein. This study shows that the nanostructures produced by the Advanced Nanochelating Technology have potent adjuvant effects on alum-based SARS-CoV-2 vaccines to not only compensate for alum weakness in inducing the cellular immune responses by smart regulation of the immune system but also significantly improve the humoral and cellular immune responses simultaneously.

Safety and efficacy of dendritic cell vaccine for COVID-19 prevention after 1-Year follow-up: phase I and II clinical trial final result

Introduction

Interim analysis of phase I and phase II clinical trials of personalized vaccines made from autologous monocyte-derived dendritic cells (DCs) incubated with S-protein of SARS-CoV-2 show that this vaccine is safe and well tolerated. Our previous report also indicates that this vaccine can induce specific T-cell and B cell responses against SARS-CoV-2. Herein, we report the final analysis after 1 year of follow-up regarding its safety and efficacy in subjects of phase I and phase II clinical trials.

Methods

Adult subjects (>18 years old) were given autologous DCs derived from peripheral blood monocytes, which were incubated with the S-protein of SARS-CoV-2. The primary outcome is safety in phase I clinical trials. Meanwhile, optimal antigen dosage is determined in phase II clinical trials. Corona Virus Disease 2019 (COVID-19) and Non-COVID-19 adverse events (AEs) were observed for 1 year.

Results

A total of 28 subjects in the phase I clinical trial were randomly assigned to nine groups based on antigen and Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) dosage. In the phase II clinical trial, 145 subjects were randomly grouped into three groups based on antigen dosage. During the 1-year follow-up period, 35.71% of subjects in phase I and 16.54% in phase II had non-COVID AEs. No subjects in phase I experienced moderate-severe COVID-19. Meanwhile, 4.31% of subjects in phase II had moderate-severe COVID-19. There is no difference in both COVID and non-COVID-19 AEs between groups.

Conclusions

After 1 year of follow-up, this vaccine is proven safe and effective for preventing COVID-19. A phase III clinical trial involving more subjects should be conducted to establish its efficacy and see other possible side effects.

Positively Charged-Amylose-Entangled Au-Nanoparticles Acting as Protein Carriers and Potential Adjuvants to SARS-CoV-2 Subunit Vaccines

The COVID-19 pandemic continues to spread worldwide. To protect and control the spread of SARS-CoV-2, varieties of subunit vaccines based on spike (S) proteins have been approved for human applications. Here, we report a new subunit vaccine design strategy that functions as both an antigen carrier and an adjuvant in immunization to elicit high-level immune responses. The complex of 2-hydroxypropyl-trimethylammonium chloride chitosan and amylose entangles Au nanoparticles (HTCC/amylose/AuNPs) forming 40 nm nanocarriers with a positive charge. The obtained positively charged nanoparticles reveal many merits, including the larger S protein loading capacity in PBS buffer, higher cellular uptake ability, and lower cell cytotoxicity, supporting their potential as safe vaccine nanocarriers. Two functionalized nanoparticle subunit vaccines are prepared via loading full-length S proteins derived from SARS-CoV-2 variants. In mice, both prepared vaccines elicit high specific IgG antibodies, neutralize antibodies, and immunoglobulin IgG1 and IgG2a. The prepared vaccines also elicit robust T- and B-cell immune responses and increase CD19⁺ B cells, CD11C⁺ dendritic cells, and CD11B⁺ macrophages at the alveoli and bronchi of the immunized mice. Furthermore, the results of skin safety tests and histological observation of organs indicated in vivo safety of HTCC/amylose/AuNP-based vaccines. Summarily, our prepared HTCC/amylose/AuNP have significant potential as general vaccine carriers for the delivery of different antigens with potent immune stimulation.