Safety and Efficacy of Single-Dose Ad26.COV2.S Vaccine against Covid-19

Challenges in Emerging Vaccines and Future Promising Candidates against SARS-CoV-2 Variants

Since the COVID-19 outbreak, the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus has evolved into variants with varied infectivity. Vaccines developed against COVID-19 infection have boosted immunity, but there is still uncertainty on how long the immunity from natural infection or vaccination will last. The present study attempts to outline the present level of information about the contagiousness and spread of SARS-CoV-2 variants of interest and variants of concern (VOCs). The keywords like COVID-19 vaccine types, VOCs, universal vaccines, bivalent, and other relevant terms were searched in NCBI, Science Direct, and WHO databases to review the published literature. The review provides an integrative discussion on the current state of knowledge on the type of vaccines developed against SARS-CoV-2, the safety and efficacy of COVID-19 vaccines concerning the VOCs, and prospects of novel universal, chimeric, and bivalent mRNA vaccines efficacy to fend off existing variants and other emerging coronaviruses. Genomic variation can be quite significant, as seen by the notable differences in impact, transmission rate, morbidity, and death during several human coronavirus outbreaks. Therefore, understanding the amount and characteristics of coronavirus genetic diversity in historical and contemporary strains can help researchers get an edge over upcoming variants.

Allosteric Inhibitors of the SARS-COV-2 Papain-like Protease Domain Induce Proteasomal Degradation of Its Parent Protein NSP3

The papain-like protease of SARS-COV-2 is essential for viral replication and pathogenesis. Its location within a much larger multifunctional protein, NSP3, makes it an ideal candidate for a targeted degradation approach capable of eliminating multiple functions with a single-molecule treatment. In this work, we have developed a HiBiT-based cellular model to study NSP3 degradation and used this platform for the discovery of monovalent NSP3 degraders. We present previously unreported degradation activity of published papain-like protease inhibitors. Follow-up exploration of structure-activity relationships and mechanism-of-action studies points to the recruitment of the ubiquitin-proteasome machinery that is solely driven by site occupancy, regardless of molecular features of the ligand. Supported by HDX data, we hypothesize that binding-induced structural changes in NSP3 trigger the recruitment of an E3 ligase and lead to proteasomal degradation.

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 review of neuro-ophthalmic sequelae following COVID-19 infection and vaccination

Background

It has become increasingly clear that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect most organs in the human body, including the neurologic and ophthalmic systems. Vaccination campaigns have been developed at rapid pace around the world to protect the population from the fast-mutating virus. This review seeks to summarise current knowledge of the neuro-ophthalmic manifestations of both COVID-19 infection and vaccination.

Evidence acquisition

Electronic searches for published literature were conducted using EMBASE and MEDLINE on the 30th of July 2023. The search strategy comprised of controlled vocabulary and free-text synonyms for the following terms in various combinations: "coronavirus, COVID-19, SARS-CoV-2, 2019-nCoV, vaccination, vaccine, immunisation and neuro-ophthalmology". No time range limits were set for the literature search. Published English abstracts for articles written in a different language were screened if available.

Results

A total of 54 case reports and case series were selected for use in the final report. 34 articles documenting neuro-ophthalmic manifestations following COVID-19 infection and 20 articles with neuro-ophthalmic complications following COVID-19 vaccination were included, comprising of 79 patients in total. The most commonly occurring condition was optic neuritis, with 25 cases following COVID-19 infection and 27 cases following vaccination against COVID-19.

Conclusions

The various COVID-19 vaccines that are currently available are part of the global effort to protect the most vulnerable of the human population. The incidence of neuro-ophthalmic consequences following infection with COVID-19 is hundred-folds higher and associated with more harrowing systemic effects than vaccination against the virus.

Integration of individualized and population-level molecular epidemiology data to model COVID-19 outcomes

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with enhanced transmissibility and immune escape have emerged periodically throughout the coronavirus disease 2019 (COVID-19) pandemic, but the impact of these variants on disease severity has remained unclear. In this single-center, retrospective cohort study, we examined the association between SARS-CoV-2 clade and patient outcome over a two-year period in Chicago, Illinois. Between March 2020 and March 2022, 14,252 residual diagnostic specimens were collected from SARS-CoV-2-positive inpatients and outpatients alongside linked clinical and demographic metadata, of which 2,114 were processed for viral whole-genome sequencing. When controlling for patient demographics and vaccination status, several viral clades were associated with risk for hospitalization, but this association was negated by the inclusion of population-level confounders, including case count, sampling bias, and shifting standards of care. These data highlight the importance of integrating non-virological factors into disease severity and outcome models for the accurate assessment of patient risk.

Immunogenicity and safety of heterologous versus homologous prime-boost schedules with inactivated and adenoviral vectored SARS-CoV-2 vaccines - A prospective multi-center study

Background

During the peak of Coronavirus disease (COVID-19) pandemic in Thailand when the emergence of delta variant reduced the efficacy of inactivated vaccine, Thailand had abundance of inactivated vaccine but mRNA vaccine was not available and the supply of adenoviral-vectored vaccine was limited. The heterologous vaccination using CoronaVac and ChAdOx1-nCoV-19 vaccines was applied. We aim to compare the immunogenicity of immune response of primary vaccination with homologous ChAdOx1 nCoV-19 and heterologous vaccination with CoronaVac and ChAdOx1 nCoV-19.

Methods

A total of 430 adults, scheduled to receive ChAdOx1-nCoV-19 as their second dose of primary COVID-19 vaccination, were enrolled. Participants were classified into two groups based on the first dose vaccine as CoronaVac (heterologous group) or ChAdOx1 nCoV-19 (homologous group). The primary outcome was antibodies to the SARS-CoV-2 spike protein receptor binding domain (anti-RBD) titres at 28 days after the second dose of vaccination. Secondary outcomes were anti-RBD titres at 90 days, surrogate viral neutralizing test (sVNT) at 28 and 90 days, and adverse events.

Findings

In 358 participants with correct vaccine interval, the anti-RBD geometric mean titre ratio for the heterologous versus homologous group was 0.55 (95%CI; 0.44-0.067); p < 0.001 at day 28, and 0.80 (95%CI; 0.65-1.00); P = 0.05 at day 90. Median sVNT neutralizing activity was not significantly different in the heterologous versus homologous group at 28 days (93.5 vs 92.7 %); p = 0.13, but significantly higher in the heterologous group at day 90 (82.9 vs 76.4 %); p = 0.01.

Interpretation

The homologous vaccination resulted in higher anti-RBD titres at 28 days after vaccination, but titres in the homologous group showed more rapid decline at 90 days. In the sVNT assay, median neutralization was similar at 28 days, but was longer-lasting and higher in the heterologous group at 90 days.

Funding

This research received funding from the Royal College of Physicians of Thailand special grant 2021 for research initiative during COVID-19 pandemic.

Burden and Impact of Reactogenicity among Adults Receiving COVID-19 Vaccines in the United States and Canada: Results from a Prospective Observational Study

As SARS-CoV-2 variants continue to emerge, vaccination remains a critical tool to reduce the COVID-19 burden. Vaccine reactogenicity and the impact on work productivity/daily activities are recognized as contributing factors to vaccine hesitancy. To encourage continued COVID-19 vaccination, a more complete understanding of the differences in reactogenicity and impairment due to vaccine-related side effects across currently available vaccines is necessary. The 2019nCoV-406 study (n = 1367) was a prospective observational study of reactogenicity and associated impairments in adults in the United States and Canada who received an approved/authorized COVID-19 vaccine. Compared with recipients of mRNA COVID-19 booster vaccines, a smaller percentage of NVX-CoV2373 booster recipients reported local and systemic reactogenicity. This study's primary endpoint (percentage of participants with ≥50% overall work impairment on ≥1 of the 6 days post-vaccination period) did not show significant differences. However, the data suggest that NVX-CoV2373 booster recipients trended toward being less impaired overall than recipients of an mRNA booster; further research is needed to confirm this observed trend. The results of this real-world study suggest that NVX-CoV2373 may be a beneficial vaccine option with limited impact on non-work activities, in part due to the few reactogenicity events after vaccination.

Studying SARS-CoV-2 interactions using phage-displayed receptor binding domain as a model protein

SARS-CoV-2 receptor binding domain (RBD) mediates viral entry into human cells through its interaction with angiotensin converting enzyme 2 (ACE2). Most neutralizing antibodies elicited by infection or vaccination target this domain. Such a functional relevance, together with large RBD sequence variability arising during viral spreading, point to the need of exploring the complex landscape of interactions between RBD-derived variants, ACE2 and antibodies. The current work was aimed at developing a simple platform to do so. Biologically active and antigenic Wuhan-Hu-1 RBD, as well as mutated RBD variants found in nature, were successfully displayed on filamentous phages. Mutational scanning confirmed the global plasticity of the receptor binding motif within RBD, highlighted residues playing a critical role in receptor binding, and identified mutations strengthening the interaction. The ability of vaccine-induced antibodies to inhibit ACE2 binding of many mutated RBD variants, albeit at different extents, was shown. Amino acid replacements which could compromise such inhibitory potential were underscored. The expansion of our approach could be the starting point for a large-scale phage-based exploration of diversity within RBD of SARS-CoV-2 and related coronaviruses, useful to understand structure-function relationships, to engineer RBD proteins, and to anticipate changes to watch during viral evolution.

DNA origami vaccine (DoriVac) nanoparticles improve both humoral and cellular immune responses to infectious diseases

Current SARS-CoV-2 vaccines have demonstrated robust induction of neutralizing antibodies and CD4+ T cell activation, however CD8+ responses are variable, and the duration of immunity and protection against variants are limited. Here we repurposed our DNA origami vaccine platform, DoriVac, for targeting infectious viruses, namely SARS-CoV-2, HIV, and Ebola. The DNA origami nanoparticle, conjugated with infectious-disease-specific HR2 peptides, which act as highly conserved antigens, and CpG adjuvant at precise nanoscale spacing, induced neutralizing antibodies, Th1 CD4+ T cells, and CD8+ T cells in naïve mice, with significant improvement over a bolus control. Pre-clinical studies using lymph-node-on-a-chip systems validated that DoriVac, when conjugated with antigenic peptides or proteins, induced promising cellular immune responses in human cells. These results suggest that DoriVac holds potential as a versatile, modular vaccine platform, capable of inducing both humoral and cellular immunities. The programmability of this platform underscores its potential utility in addressing future pandemics.

The role of vaccines in the COVID-19 pandemic: what have we learned?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged late in 2019 and caused the coronavirus disease 2019 (COVID-19) pandemic that has so far claimed approximately 20 million lives. Vaccines were developed quickly, became available in the end of 2020, and had a tremendous impact on protection from SARS-CoV-2 mortality but with emerging variants the impact on morbidity was diminished. Here I review what we learned from COVID-19 from a vaccinologist's perspective.

The mRNA vaccine, a swift warhead against a moving infectious disease target

INTRODUCTION

The rapid development of mRNA vaccines against SARS-CoV-2 has revolutionized vaccinology, offering hope for swift responses to emerging infectious diseases. Initially met with skepticism, mRNA vaccines have proven effective and safe, reducing vaccine hesitancy amid the evolving COVID-19 pandemic. The COVID-19 pandemic has demonstrated that the time required to modify mRNA vaccines to counter new mutant strains is significantly shorter than the time it takes for pathogens to mutate and generate new variants that can thrive in vaccinated populations. This highlights the notion that mRNA vaccine technology appears to be outpacing viruses in the ongoing evolutionary race.

AREAS COVERED

This review article offers valuable insights into several crucial aspects of mRNA vaccine development and deployment, including the fundamentals of mRNA vaccine design and synthesis, the utilization of delivery systems, considerations regarding vaccine safety, the longevity of the immune response, strategies for modifying the original mRNA vaccine to address emerging mutant strains, as well as addressing vaccine hesitancy and potential approaches to mitigate reluctance.

EXPERT OPINION

Challenges such as stability, storage, manufacturing complexities, production capacity, allergic reactions, long-term effects, accessibility, and misinformation must be addressed. Despite these hurdles, mRNA vaccine technology holds promise for revolutionizing future vaccination strategies.

The Interrelationship between HIV Infection and COVID-19: A Review of the Literature

The Corona Virus Disease 2019 (COVID-19) pandemic resulting from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to significant morbidity and mortality in patients and put a strain on healthcare systems worldwide. The clinical characteristics and results of COVID-19 in immunosuppressed patients, such as people living with human immunodeficiency virus (PLWH), considered at higher risk of severe disease, are not well-characterized. Accumulated evidence indicates that COVID-19 and the human immunodeficiency virus (HIV) can interact in various ways. This review explored the similarities and differences in virology between SARS-CoV-2 and HIV, the effect of the COVID-19 vaccine on PLWH, the impact of the COVID-19 pandemic on PLWH care and prevention, and the influence of HIV-related factors on COVID-19. Discovering the potential link between HIV and COVID-19 may provide a novel way to avoid the factors of HIV and SARS-CoV-2 co-infection and advance future research.

Fetal gene therapy

Fetal gene therapy was first proposed toward the end of the 1990s when the field of gene therapy was, to quote the Gartner hype cycle, at its "peak of inflated expectations." Gene therapy was still an immature field but over the ensuing decade, it matured and is now a clinical and market reality. The trajectory of treatment for several genetic diseases is toward earlier intervention. The ability, capacity, and the will to diagnose genetic disease early-in utero-improves day by day. A confluence of clinical trials now signposts a trajectory toward fetal gene therapy. In this review, we recount the history of fetal gene therapy in the context of the broader field, discuss advances in fetal surgery and diagnosis, and explore the full ambit of preclinical gene therapy for inherited metabolic disease.

Gene-based COVID-19 vaccines: Australian perspectives in a corporate and global context

Pandemic management requires societal coordination, global orchestration, respect for human rights and defence of ethical principles. Yet some approaches to the COVID-19 pandemic, driven by socioeconomic, corporate, and political interests, have undermined key pillars of ethical medical science. We explore significant mistakes that may have occurred in recent pandemic control, in order to better navigate the future. Within corporate and geopolitical infrastructure, we review the COVID-19 pandemic and novel mRNA and viral-vector DNA COVID-19 vaccines, deployed by wealthy western countries. The pandemic, together with rollouts of unconventional, gene-based vaccine technology, has provided experimental opportunity to engineer social control of entire populations. The haste and scale of development, production, and distribution of these new pharmaceuticals is unprecedented in history. Key phase III clinical trials for these products are yet to be fully completed, despite administration to billions of people. Mass vaccination of workforces has been mandated, and vaccine mandates correlate with excess mortality. Many independent data sets concur - we have experienced a pandemic of viral illness, followed by a pandemic of vaccine injury. For Australia, matters have operated the other way around. Vaccination followed later by the main viral wave. Australian excess mortality data correlates with this. Neither risk nor cost can justify these products for the vast majority of people. Lack of efficacy against infection and transmission, and the equivalent benefits of natural immunity, obviate mandatory therapeutics. With the many gene-based pharmaceuticals planned, a new era of pathology lies ahead. We should pause, reflect, and reaffirm essential freedoms, welcome the end of the COVID-19 pandemic, embrace natural immunity, and lift all mandated medical therapy.

An Outline of the Immunogenic Potential of Progressing SARSCoV- 2 Vaccine Technologies among Children and Adolescents

BACKGROUND

SARS-CoV-2, a highly dynamic beta-coronavirus, can afflict all age groups. Notably, over 16100 mortalities have been recorded among children as yet. In this regard, many vaccine projects are operational to assess immuno-potency among young cohorts. A bulk of reports have evidenced the efficacy of these immunization technologies in the elderly population, though the impact is yet to be determined among children.

OBJECTIVES

This review is envisioned to outline the current efficacy of contributing vaccine technologies and examine the dose-dependent impact of immunization regimens in lowering the risks of SARS-CoV-2 infections among children and adolescents. Furthermore, the current review exclusively estimated the vaccine impact at current doses.

METHODS

A total of 52 research papers extracted from PubMed, Pubmed Central, Science Direct, Research Gate, Google Scholar and Semantic Scholar were screened along with an emphasis on patents. Inclusion criteria involved all published reports directly or indirectly linked to the contributing vaccine candidates that are operational among the young cohort. Unrelated research papers were excluded from the study. Key search terminologies included information on vaccine identifiers, such as name, type and clinical trial ID, and successively restricted to children and adolscents age groups.

RESULTS

Several vaccine designs, such as mRNA-based vaccinations, viral vector vaccines, DNA vaccines, inactivated vaccines, recombinant vaccines, and protein-based immunizations, are being examined at various stages of clinical trials to gauge the effects on children and adolescents. With reference to the published reports, the mRNA 1273 (1610 GMT; 6-10 yrs, 1401 GMT; 12-15 yrs), BNT162b2 (1407 GMT; 6 months- <2 yrs, 1535 GMT; 2-4 yrs, 4583 GMT; 5-11 yrs, 1239.5 GMT; 12-15 yrs) and Ad5 nCoV (1037.5 GMT; 6-17 yrs) offered relatively high neutralization titers with sharp seroconversion rates compared to MVC-COV1901 (648.5 GMT; 12-17 yrs) and ZyCoV-D (133.49 GMT; 12-17 yrs), which produced modest immune responses.

CONCLUSION

Currently, the WHO is analyzing emerging evidence to issue an emergency use list of vaccines for vaccinating children and adolescents.

SARS-CoV-2 vaccine immunogenicity for people living with HIV: A systematic review and meta-analysis

BACKGROUND

Previous publications on the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in people living with HIV (PLWH) have reported inconsistent results. Additionally, a meta-analysis investigating the immunogenicity in PLWH after the third SARS-CoV-2 vaccine dose is lacking. In this article we aim to provide a systematic review and a meta-analysis studying the immunogenicity of SARS-CoV-2 vaccines in PLWH and to identify potential drivers for antibody response in PLWH.

METHODS

We used three databases (PubMed, Embase and Web of Science) to conduct our review. Studies with information on numbers of PLWH producing immunoglobulin G (IgG) antibodies or neutralizing antibodies were included.

RESULTS

The meta-analysis included 59 studies and illustrated a pooled serological response of 87.09% in the 10 343 PLWH after they received a SARS-CoV-2 vaccine. High CD4 T-cell counts and low viral load indicated that the study populations had HIV that was well treated, despite varying in location. The pooled effect increased to 91.62% for 8053 PLWH when excluding studies that used inactivated vaccines (BBIBP-CorV and CoronaVac). For the third vaccine dose, the pooled effect was 92.35% for 1974 PLWH. Additionally, weighted linear regression models demonstrated weak relationships between CD4 T-cell count, percentages of people with undetectable HIV load, and age compared with the percentages of PLWH producing a serological response. However, more research is needed to determine the effect of those factors on SARS-CoV-2 vaccine immunogenicity in PLWH.

CONCLUSION

SARS-CoV-2 vaccines show a favourable effect on immunogenicity in PLWH. However, the results are not ideal. This meta-analysis suggests that a third SARS-CoV-2 vaccine dose and good HIV treatment procedures are vital to induce a good immunogenicity in PLWH.

Obesity and its Relationship with Covid-19: A Review of the Main Pharmaceutical Aspects

Important physiological changes are observed in patients with obesity, such as intestinal permeability, gastric emptying, cardiac output, and hepatic and renal function. These differences can determine variations in the pharmacokinetics of different drugs and can generate different concentrations at the site of action, which can lead to sub therapeutic or toxic concentrations. Understanding the physiological and immunological processes that lead to the clinical manifestations of COVID-19 is essential to correlate obesity as a risk factor for increasing the prevalence, severity, and lethality of the disease. Several drugs have been suggested to control COVID- 19 like Lopinavir, Ritonavir, Ribavirin, Sofosbuvir, Remdesivir, Oseltamivir, Oseltamivir phosphate, Oseltamivir carboxylate, Hydroxychloroquine, Chloroquine, Azithromycin, Teicoplanin, Tocilizumab, Anakinra, Methylprednisolone, Prednisolone, Ciclesonide and Ivermectin. Similarly, these differences between healthy people and obese people can be correlated to mechanical factors, such as insufficient doses of the vaccine for high body mass, impairing the absorption and distribution of the vaccine that will be lower than desired or can be linked to the inflammatory state in obese patients, which can influence the humoral immune response. Additionally, different aspects make the obese population more prone to persistent symptoms of the disease (long COVID), which makes understanding these mechanisms fundamental to addressing the implications of the disease. Thus, this review provides an overview of the relationship between COVID-19 and obesity, considering aspects related to pharmacokinetics, immunosuppression, immunization, and possible implications of long COVID in these individuals.

Safety and efficacy of COVID-19 vaccines: A systematic review and meta-analysis of controlled and randomized clinical trials

Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of vaccines, which raised the question about the safety and efficacy of the approved vaccines. The purpose of this study is to look at the effectiveness and safety of vaccine platforms against the incidence of COVID-19. The literature search was performed on PubMed/Medline, Cochrane, and clinical trials.gov databases for studies published between 1 January 2020 and 19 February 2022. Preferred Reporting Items for Systemic Review and Meta-Analysis Statement guidelines were followed. Among 284 articles received by keywords, a total of 11 studies were eligible according to the inclusion and exclusion criteria (studies in special populations, e.g., pregnant women, paediatric patients, editorials, case reports, review articles, preclinical and in vitro studies) of the study. A total of 247,186 participants were considered for randomisation at baseline, among them, 129,572 (52.42%) were provided with vaccine (Intervention group) and 117,614 (47.58%) with the placebo (Control group). A pooled fold change estimation of 0.19 (95% CI: 0.12-0.31, p < 0.0001) showed significant protection against the incidence of COVID-19 in the vaccines received group versus the placebo group. mRNA based, inactivated vaccines and non-replicating viral vector-based vaccines showed significantly protection against the incidence of COVID-19 compared to placebo with pooled fold change estimation was 0.08 (95% CI: 0.06-0.10), 0.20 (95% CI: 0.14-0.29) and 0.36 (95% CI: 0.28-0.46), respectively. Injection site discomfort and fatigue were the most common side effect observed in mRNA, non-replicating viral vector, inactivated, and protein subunit-based vaccines. All the approved vaccines were found safe and efficacious but mRNA-based vaccines were found to be more efficacious against SARS-CoV-2 than other platforms.

Vaccinating against a Novel Pathogen: A Critical Review of COVID-19 Vaccine Effectiveness Evidence

We study the experience with COVID-19 vaccination of an initially naïve population, which can inform planning for vaccination against the next novel, highly transmissible pathogen. We focus on the first two pandemic years (wild strain through Delta), because after the Omicron wave in early 2022, very few people were still SARS-CoV-2-naïve. Almost all were vaccinated, infected, or often both. We review the evidence on COVID-19 vaccine effectiveness (VE) and waning effectiveness over time and the relative effectiveness of the four principal vaccines used in developed Western countries: BNT162b2 (Pfizer-BioNTech), mRNA1273 (Moderna), Ad26.CoV2.S (Johnson&Johnson), and ChAdOx1-S (AstraZeneca). As a basis for our analysis, we conducted a PRISMA-compliant review of all studies on PubMed through 15 August 2022, reporting VE against four endpoints for these four vaccines: any infection, symptomatic infection, hospitalization, and death. The mRNA vaccines (BNT162b2, mRNA1273) had high initial VE against all endpoints but protection waned after approximately six months, with BNT162b2 declining faster than mRNA1273. Both mRNA vaccines outperformed the viral vector vaccines (Ad26.CoV2.S and ChAdOx1-S). A third "booster" dose, roughly six months after the initial doses, substantially reduced symptomatic infection, hospitalization, and death. In hindsight, a third dose should be seen as part of the normal vaccination schedule. Our analysis highlights the importance of the real-time population-level surveillance needed to assess evidence for waning, and the need for rapid regulatory response to this evidence.

Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review

Despite widespread mass rollout programs, the rapid spread of the SARS-CoV-2 Omicron variant called into question the effectiveness of the existing vaccines against infection, hospitalization, severity, and mortality compared to previous variants. This systematic review summarizes and compares the effectiveness of the COVID-19 vaccines, with respect to the above outcomes in adults, children, and adolescents. A comprehensive literature search was undertaken on several databases. Only 51 studies met our inclusion criteria, revealing that the protection from primary vaccination against Omicron infection is inferior to protection against Delta and Alpha infections and wanes faster over time. However, mRNA vaccine boosters were reported to reestablish effectiveness, although to a lower extent against Omicron. Nonetheless, primary vaccination was shown to preserve strong protection against Omicron-associated hospitalization, severity, and death, even months after last dose. However, boosters provide more robust and longer-lasting protection against hospitalizations due to Omicron as compared to only primary series.

Emerging heterologous mRNA-based booster strategies within the COVID-19 vaccine landscape

Messenger RNA (mRNA)-based vaccine platforms used for the development of mRNA-1273 and BNT162b2 have provided a robust adaptable approach to offer protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, as variants of concern (VoCs), such as omicron and associated sub-variants, emerge, boosting strategies must also adapt to keep pace with the changing landscape. Heterologous vaccination regimens involving the administration of booster vaccines different than the primary vaccination series offer a practical, effective, and safe approach to continue to reduce the global burden of coronavirus disease 2019 (COVID-19). To understand the immunogenicity, effectiveness, and safety of heterologous mRNA-based vaccination strategies, relevant clinical and real-world observational studies were identified and summarized. Overall, heterologous boosting strategies with mRNA-based vaccines that are currently available and those in development will play an important global role in protecting individuals from COVID-19 caused by emerging VoCs.

Comparing the Efficacy and Adverse Events of Available COVID-19 Vaccines Through Randomized Controlled Trials: Updated Systematic Review and Network Meta-analysis

BACKGROUND

Different vaccines have so far been developed and approved to cope with COVID-19 in the world. The aim of this updated network meta-analysis (NMA) was to compare and rank all available vaccines in terms of efficacy and complications simultaneously. Study Design: A systematic review.

METHODS

Three major international databases, including Web of Science, Medline via PubMed, and Scopus, were searched through September 2023. The transitivity assumption was evaluated qualitatively in terms of epidemiologic effect modifiers. The exposure of interest in this study was receiving any available COVID-19 vaccine, and the primary outcome of interest was the incidence of symptomatic COVID-19. In this NMA, the relative risk of symptomatic COVID-19 was used to summarize the efficacy of vaccines in preventing COVID-19. The data were analyzed using the frequentist-based approach, and the results were reported using a random-effects model. Finally, the vaccines were ranked using a P-score.

RESULTS

In total, 34 randomized controlled trials (RCTs) met the eligibility criteria for this systematic review and NMA out of 3682 retrieved references. Based on the results of the NMA, mRNA-1273 was the most effective vaccine in preventing COVID-19 and demonstrated the highest P-score (0.93). The relative risk (RR) for mRNA-1273 versus placebo was 0.07 (95% confidence interval [CI]: 0.03, 0.17). The second and third-ranked vaccines were BNT-162b2 (RR=0.08; 95% CI: 0.04, 0.15; P-score=0.93) and Gam-COVID-Vac (0.09; 95% CI: 0.03, 0.25; 0.88).

CONCLUSION

Based on the results of this NMA, it seems that all available vaccines were effective in COVID-19 prevention. However, the top three ranked vaccines were mRNA-1273, BNT-162b2, and Gam-COVID-Vac, respectively.

Clinical trials of pharmacological interventions for SARS-CoV-2 published in leading medical journals report adherence but not how it was assessed

AIMS

Adherence to pharmacological interventions in clinical trials is crucial for accurate identification of beneficial and adverse outcomes. The ways in which adherence to interventions should be reported in trial publications are described in the Template for Intervention Description and Replication (TIDieR), a 12-item extension of the Consolidated Standards of Reporting Trials reporting guidelines. The objective of this study was to assess compliance with TIDieR Items 11 and 12 of randomized controlled trials (RCTs) of interventions in SARS-CoV-2 infection published in 5 selected journals during 2021.

METHODS

We assessed pharmacological interventions for SARS-CoV-2 infection reported in RCTs published in 2021 in the Annals of Internal Medicine, The BMJ, JAMA, The Lancet and The New England Journal for Medicine for compliance with TIDieR items addressing intervention adherence (Items 11 and 12). We calculated proportional adherence for pharmacological and comparator interventions where available.

RESULTS

We found 75 eligible RCTs. Twenty-eight (37%) reported results of SARS-CoV-2 vaccinations. Compliance with Items 11 and 12 could be assessed in 71 of these 75. Of the 71 RCTs, 37 (52%) reported how adherence was assessed (Item 11), and 70 reported adherence rates (Item 12). Only 1 of the 71 RCTs (1.4%, 0-7.6%) fully complied with TIDieR Items 11 and 12.

CONCLUSION

Half of RCTs of SARS-CoV-2 pharmacological interventions published in leading medical journals in 2021 complied with reporting of how adherence assessments were made and almost none complied with both TIDieR Items 11 and 12. The implications for interpretation, application and replication of findings based on these publications warrant consideration.

Bioinspired Spatiotemporal Management toward RNA Therapies

Ribonucleic acid (RNA)-based therapies have become an attractive topic in disease intervention, especially with some that have been approved by the FDA such as the mRNA COVID-19 vaccine (Comirnaty, Pfizer-BioNTech, and Spikevax, Moderna) and Patisiran (siRNA-based drug for liver delivery). However, extensive applications are still facing challenges in delivering highly negatively charged RNA to the targeted site. Therapeutic delivery strategies including RNA modifications, RNA conjugates, and RNA polyplexes and delivery platforms such as viral vectors, nanoparticle-based delivery platforms, and hydrogel-based delivery platforms as potential nucleic acid-releasing depots have been developed to enhance their cellular uptake and protect nucleic acid from being degraded by immune systems. Here, we review the growing number of viral vectors, nanoparticles, and hydrogel-based RNA delivery systems; describe RNA loading/release mechanism induced by environmental stimulations including light, heat, pH, or enzyme; discuss their physical or chemical interactions; and summarize the RNA therapeutics release period (temporal) and their target cells/organs (spatial). Finally, we describe current concerns, highlight current challenges and future perspectives of RNA-based delivery systems, and provide some possible research areas that provide opportunities for clinical translation of RNA delivery carriers.

Sociodemographic and socioeconomic disparities in COVID-19 vaccine uptake in Belgium: a nationwide record linkage study

BACKGROUND

Recent studies have identified important social inequalities in SARS-CoV-2 infections and related COVID-19 outcomes in the Belgian population. The aim of our study was to investigate the sociodemographic and socioeconomic characteristics associated with the uptake of COVID-19 vaccine in Belgium.

METHODS

We conducted a cross-sectional analysis of the uptake of a first COVID-19 vaccine dose among 5 342 110 adults (≥18 years) in Belgium on 31 August 2021. We integrated data from four national data sources: the Belgian vaccine register (vaccination status), COVID-19 Healthdata (laboratory test results), DEMOBEL (sociodemographic/socioeconomic data) and the Common Base Register for HealthCare Actors (individuals licensed to practice a healthcare profession in Belgium). We used multivariable logistic regression analysis for identifying characteristics associated with not having obtained a first COVID-19 vaccine dose in Belgium and for each of its three regions (Flanders, Brussels and Wallonia).

RESULTS

During the study period, 10% (536 716/5 342 110) of the Belgian adult population included in our study sample was not vaccinated with a first COVID-19 vaccine dose. A lower COVID-19 vaccine uptake was found among young individuals, men, migrants, single parents, one-person households and disadvantaged socioeconomic groups (with lower levels of income and education, unemployed). Overall, the sociodemographic and socioeconomic disparities were comparable for all regions.

CONCLUSIONS

The identification of sociodemographic and socioeconomic disparities in COVID-19 vaccination uptake is critical to develop strategies guaranteeing a more equitable vaccination coverage of the Belgian adult population.

Humoral Immune Responses following COVID-19 Vaccinations among Adults in Tanzania

COVID-19 vaccination remains to be the most important intervention in the fight against the pandemic. The immunity among the vaccinated population and its durability can significantly vary due to various factors. This study investigated the humoral immune responses among individuals who received any of the COVID-19 vaccines approved for use in Tanzania. A total of 1048 randomly selected adults who received COVID-19 vaccines at different time points were enrolled and humoral immune responses (IR) were tested at baseline and three months later (960, 91.6%). The level of SARS-CoV-2 anti-spike/receptor binding domain (RBD) IgG, anti-nucleocapsid IgG, and IgM antibodies were determined using a commercially available chemiluminescent microparticle immunoassay. Descriptive data analysis was performed using STATA version 18 and R. At baseline, serum IgG against anti-spike/RBD was detected in 1010/1048 (96.4%) participants (95%CI: 94.9-97.5) and 98.3% (95%CI: 97.3-99) three months later. The IgG against the SARS-CoV-2 nucleocapsid proteins were detected in 40.8% and 45.3% of participants at baseline and follow-up, respectively. The proportion of seroconverters following vaccination and mean titers of anti-spike/RBD antibodies were significantly more among those who had past SARS-CoV-2 infection than in those with no evidence of past infection, (p < 0.001). Only 0.5% of those who had detectable anti-spike/RBD antibodies at baseline were negative after three months of follow-up and 1.5% had breakthrough infections. The majority of participants (99.5%) had detectable anti-spike/RBD antibodies beyond 6 months post-vaccination. The proportion of Tanzanians who mounted humoral IR following COVID-19 vaccination was very high. Seroconversions, as well as the mean titers and durability of humoral IR, were significantly enhanced by exposure to natural SARS-CoV-2 infection. In view of the limited availability of COVID-19 vaccines as well as challenges to completing subsequent doses, booster doses could only be suggested to high-risk groups.

Vaccine-associated corneal graft rejection following SARS-CoV-2 vaccination: a CDC-VAERS database analysis

PURPOSE

To evaluate the cases of corneal graft rejection following SARS-CoV-2 vaccination reported to Centers for Disease Control and Prevention Vaccine Adverse Event Reporting System.

METHODS

A descriptive analysis of the demographics, clinical history and presentation was performed. We evaluated the correlation between the vaccines and duration of vaccine-associated graft rejection (VAR) onset following vaccination using a one-way analysis of variance test. A post hoc analysis was performed between VAR onset-interval following vaccination dose and vaccine type. Finally, a 30-day cumulative incidence analysis was performed to assess the risk of VAR in short term following different doses, vaccines and type of corneal transplantation.

RESULTS

A total of 55 eyes of 46 patients were diagnosed with VAR following vaccination with BNT162b2 (73.91%) and mRNA-1273 (26.09%). The mean age of the patients was 62.76±15.83 years, and 28 (60.87%) were female. The patients diagnosed with VAR had undergone penetrating keratoplasty (61.82%), Descemet membrane endothelial keratoplasty (12.73%), descemet stripping endothelial keratoplasty (18.18%), anterior lamellar keratoplasty (3.64%) and corneal limbal allograft transplantation (1.82%). The mean time for VAR since penetrating and endothelial keratoplasty was 8.42±9.23 years and 4.18±4.40 years, respectively. 45.65% of the cases of VAR were reported after the second dose of vaccine. The duration of VAR onset was significantly shorter after the second dose compared with the first and booster doses (p=0.0165) and in patients who underwent endothelial keratoplasty compared with penetrating keratoplasty (p=0.041).

CONCLUSIONS

This study outlines a possible temporal relationship between corneal graft rejection and SARS-CoV-2 vaccination. An earlier onset of VAR was observed in patients who had a history of endothelial keratoplasty and following the second dose of vaccination.

Intranasal murine pneumonia virus-vectored SARS-CoV-2 vaccine induces mucosal and serum antibodies in macaques

Next-generation SARS-CoV-2 vaccines are needed that induce systemic and mucosal immunity. Murine pneumonia virus (MPV), a murine homolog of respiratory syncytial virus, is attenuated by host-range restriction in nonhuman primates and has a tropism for the respiratory tract. We generated MPV vectors expressing the wild-type SARS-CoV-2 spike protein (MPV/S) or its prefusion-stabilized form (MPV/S-2P). Both vectors replicated similarly in cell culture and stably expressed S. However, only S-2P was associated with MPV particles. After intranasal/intratracheal immunization of rhesus macaques, MPV/S and MPV/S-2P replicated to low levels in the airways. Despite its low-level replication, MPV/S-2P induced high levels of mucosal and serum IgG and IgA to SARS-CoV-2 S or its receptor-binding domain. Serum antibodies from MPV/S-2P-immunized animals efficiently inhibited ACE2 receptor binding to S proteins of variants of concern. Based on its attenuation and immunogenicity in macaques, MPV/S-2P will be further evaluated as a live-attenuated vaccine for intranasal immunization against SARS-CoV-2.

Transient Autoreactive PF4 and Antiphospholipid Antibodies in COVID-19 Vaccine Recipients

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare autoimmune condition associated with recombinant adenovirus (rAV)-based COVID-19 vaccines. It is thought to arise from autoantibodies targeting platelet factor 4 (aPF4), triggered by vaccine-induced inflammation and the formation of neo-antigenic complexes between PF4 and the rAV vector. To investigate the specific induction of aPF4 by rAV-based vaccines, we examined sera from rAV vaccine recipients (AZD1222, AD26.COV2.S) and messenger RNA (mRNA) based (mRNA-1273, BNT162b2) COVID-19 vaccine recipients. We compared the antibody fold change (FC) for aPF4 and for antiphospholipid antibodies (aPL) of rAV to mRNA vaccine recipients. We combined two biobanks of Dutch healthcare workers and matched rAV-vaccinated individuals to mRNA-vaccinated controls, based on age, sex and prior history of COVID-19 (AZD1222: 37, Ad26.COV2.S: 35, mRNA-1273: 47, BNT162b2: 26). We found no significant differences in aPF4 FCs after the first (0.99 vs. 1.08, mean difference (MD) = -0.11 (95% CI -0.23 to 0.057)) and second doses of AZD1222 (0.99 vs. 1.10, MD = -0.11 (95% CI -0.31 to 0.10)) and after a single dose of Ad26.COV2.S compared to mRNA-based vaccines (1.01 vs. 0.99, MD = 0.026 (95% CI -0.13 to 0.18)). The mean FCs for the aPL in rAV-based vaccine recipients were similar to those in mRNA-based vaccines. No correlation was observed between post-vaccination aPF4 levels and vaccine type (mean aPF difference -0.070 (95% CI -0.14 to 0.002) mRNA vs. rAV). In summary, our study indicates that rAV and mRNA-based COVID-19 vaccines do not substantially elevate aPF4 levels in healthy individuals.

Improved detection of infection with SARS-CoV-2 Omicron variants of concern in healthcare workers by a second-generation rapid antigen test

IMPORTANCE

The results from this study demonstrate the usefulness of a second-generation rapid antigen test for early detection of infection with the SARS-CoV-2 Omicron variant of concern (VoC) and reveal a higher sensitivity to detect immune escape Omicron VoCs compared to a first-generation rapid antigen test (89.4% vs 83.7%) in the high-risk group of healthcare workers.

Real-Life Experience in the Efficacy and Safety of COVID-19 Vaccination in Patients with Advanced Cirrhosis

COVID-19 infections accelerate liver decompensation and serious liver-related co-morbidities. The aim is to evaluate the safety and impact of COVID vaccines on hepatic disease progression in patients with advanced liver disease and to identify parameters that predict the occurrence of complications. The study involved 70 patients with advanced liver disease who were vaccinated with different COVID vaccines from January 2021 to April 2022. They were evaluated clinically. The laboratory investigation included a complete blood count, liver and kidney function tests, calculation of CTP and MELD scores, plasma levels of ammonia, abdominal ultrasound, and upper GI endoscopy. Twenty patients had experienced complications 64 ± 12 days from the last dose of a vaccination. Twenty patients (28.6%) developed hepatic decompensation and hypothyroidism (n = 11, 15.7%), and five (7.14%) patients developed splanchnic thrombosis. There were no COVID-19 reinfections except for two patients who received Sinopharm and developed vaccine-associated enhanced disease (2.9%). Complications after COVID vaccinations were correlated with ALT (r = 0.279, p = 0.019), serum sodium (r = -0.30, p = 0.005), creatinine (r = 0.303, p = 0.011), liver volume (LV) (r = -0.640, p = 0.000), and MELD score (r = 0.439, p = 0.000). Multivariate logistic regression revealed that LV is the only independent predictor (p = 0.001). LV ≤ 682.3 has a sensitivity of 95.24% and a specificity of 85.71% in predicting complications with an AUC of 0.935, p < 0.001. In conclusion, the hepatic reserve and prognosis in liver cirrhosis should be evaluated prior to COVID vaccinations using the MELD score and liver volume as promising risk stratification criteria. In summary, the research proposes a novel triaging strategy that involves utilizing the MELD score and liver volume as risk stratification parameters of the hepatic reserve and prognosis of advanced liver cirrhosis prior to COVID immunization to determine who should not receive a COVID vaccination.

USP2 inhibition prevents infection with ACE2-dependent coronaviruses in vitro and is protective against SARS-CoV-2 in mice

Targeting angiotensin-converting enzyme 2 (ACE2) represents a promising and effective approach to combat not only the COVID-19 pandemic but also potential future pandemics arising from coronaviruses that depend on ACE2 for infection. Here, we report ubiquitin specific peptidase 2 (USP2) as a host-directed antiviral target; we further describe the development of MS102, an orally available USP2 inhibitor with viable antiviral activity against ACE2-dependent coronaviruses. Mechanistically, USP2 serves as a physiological deubiquitinase of ACE2, and targeted inhibition with specific small-molecule inhibitor ML364 leads to a marked and reversible reduction in ACE2 protein abundance, thereby blocking various ACE2-dependent coronaviruses tested. Using human ACE2 transgenic mouse models, we further demonstrate that ML364 efficiently controls disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as evidenced by reduced viral loads and ameliorated lung inflammation. Furthermore, we improved the in vivo performance of ML364 in terms of both pharmacokinetics and antiviral activity. The resulting lead compound, MS102, holds promise as an oral therapeutic option for treating infections with coronaviruses that are reliant on ACE2.

A prospective cohort study of preconception COVID-19 vaccination and miscarriage

STUDY QUESTION

To what extent is preconception maternal or paternal coronavirus disease 2019 (COVID-19) vaccination associated with miscarriage incidence?

SUMMARY ANSWER

COVID-19 vaccination in either partner at any time before conception is not associated with an increased rate of miscarriage.

WHAT IS KNOWN ALREADY

Several observational studies have evaluated the safety of COVID-19 vaccination during pregnancy and found no association with miscarriage, though no study prospectively evaluated the risk of early miscarriage (gestational weeks [GW] <8) in relation to COVID-19 vaccination. Moreover, no study has evaluated the role of preconception vaccination in both male and female partners.

STUDY DESIGN, SIZE, DURATION

An Internet-based, prospective preconception cohort study of couples residing in the USA and Canada. We analyzed data from 1815 female participants who conceived during December 2020-November 2022, including 1570 couples with data on male partner vaccination.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible female participants were aged 21-45 years and were trying to conceive without use of fertility treatment at enrollment. Female participants completed questionnaires at baseline, every 8 weeks until pregnancy, and during early and late pregnancy; they could also invite their male partners to complete a baseline questionnaire. We collected data on COVID-19 vaccination (brand and date of doses), history of SARS-CoV-2 infection (yes/no and date of positive test), potential confounders (demographic, reproductive, and lifestyle characteristics), and pregnancy status on all questionnaires. Vaccination status was categorized as never (0 doses before conception), ever (≥1 dose before conception), having a full primary sequence before conception, and completing the full primary sequence ≤3 months before conception. These categories were not mutually exclusive. Participants were followed up from their first positive pregnancy test until miscarriage or a censoring event (induced abortion, ectopic pregnancy, loss to follow-up, 20 weeks' gestation), whichever occurred first. We estimated incidence rate ratios (IRRs) for miscarriage and corresponding 95% CIs using Cox proportional hazards models with GW as the time scale. We used propensity score fine stratification weights to adjust for confounding.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 1815 eligible female participants, 75% had received at least one dose of a COVID-19 vaccine by the time of conception. Almost one-quarter of pregnancies resulted in miscarriage, and 75% of miscarriages occurred <8 weeks' gestation. The propensity score-weighted IRR comparing female participants who received at least one dose any time before conception versus those who had not been vaccinated was 0.85 (95% CI: 0.63, 1.14). COVID-19 vaccination was not associated with increased risk of either early miscarriage (GW: <8) or late miscarriage (GW: 8-19). There was no indication of an increased risk of miscarriage associated with male partner vaccination (IRR = 0.90; 95% CI: 0.56, 1.44).

LIMITATIONS, REASONS FOR CAUTION

The present study relied on self-reported vaccination status and infection history. Thus, there may be some non-differential misclassification of exposure status. While misclassification of miscarriage is also possible, the preconception cohort design and high prevalence of home pregnancy testing in this cohort reduced the potential for under-ascertainment of miscarriage. As in all observational studies, residual or unmeasured confounding is possible.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to evaluate prospectively the relation between preconception COVID-19 vaccination in both partners and miscarriage, with more complete ascertainment of early miscarriages than earlier studies of vaccination. The findings are informative for individuals planning a pregnancy and their healthcare providers.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Health [R01-HD086742 (PI: L.A.W.); R01-HD105863S1 (PI: L.A.W. and M.L.E.)], the National Institute of Allergy and Infectious Diseases (R03-AI154544; PI: A.K.R.), and the National Science Foundation (NSF-1914792; PI: L.A.W.). The funders had no role in the study design, data collection, analysis and interpretation of data, writing of the report, or the decision to submit the paper for publication. L.A.W. is a fibroid consultant for AbbVie, Inc. She also receives in-kind donations from Swiss Precision Diagnostics (Clearblue home pregnancy tests) and Kindara.com (fertility apps). M.L.E. received consulting fees from Ro, Hannah, Dadi, VSeat, and Underdog, holds stock in Ro, Hannah, Dadi, and Underdog, is a past president of SSMR, and is a board member of SMRU. K.F.H. reports being an investigator on grants to her institution from UCB and Takeda, unrelated to this study. S.H.-D. reports being an investigator on grants to her institution from Takeda, unrelated to this study, and a methods consultant for UCB and Roche for unrelated drugs. The authors report no other relationships or activities that could appear to have influenced the submitted work.

TRIAL REGISTRATION NUMBER

N/A.

Intranasal immunization with an RBD-hemagglutinin fusion protein harnesses preexisting immunity to enhance antigen-specific responses

Intranasal vaccines are anticipated to be powerful tools for combating many infectious diseases, including SARS-CoV-2, because they induce not only systemic immunity but also mucosal immunity at the site of initial infection. However, they are generally inefficient in inducing an antigen-specific immune response without adjuvants. Here, we developed an adjuvant-free intranasal vaccine platform that utilizes the preexisting immunity induced by previous infection or vaccination to enhance vaccine effectiveness. We made RBD-HA, a fusion of the receptor-binding domain (RBD) of spike derived from SARS-CoV-2 as a vaccine target with HA derived from influenza A virus (IAV) as a carrier protein. Intranasal immunization of previously IAV-infected mice with RBD-HA without an adjuvant elicited robust production of RBD-specific systemic IgG and mucosal IgA by utilizing both HA-specific preexisting IgG and CD4+ T cells. Consequently, the mice were efficiently protected from SARS-CoV-2 infection. Additionally, we demonstrated the high versatility of this intranasal vaccine platform by assessing various vaccine antigens and preexisting immunity associated with a variety of infectious diseases. The results of this study suggest the promising potential of this intranasal vaccine platform to address problems associated with intranasal vaccines.

Impact of vaccination on kinetics of neutralizing antibodies against SARS-CoV-2 by serum live neutralization test based on a prospective cohort

How much the vaccine contributes to the induction and development of neutralizing antibodies (NAbs) of breakthrough cases relative to those unvaccinated-infected cases is not fully understood. We conducted a prospective cohort study and collected serum samples from 576 individuals who were diagnosed with SARS-CoV-2 Delta strain infection, including 245 breakthrough cases and 331 unvaccinated-infected cases. NAbs were analysed by live virus microneutralization test and transformation of NAb titre. NAbs titres against SARS-CoV-2 ancestral and Delta variant in breakthrough cases were 7.8-fold and 4.0-fold higher than in unvaccinated-infected cases, respectively. NAbs titres in breakthrough cases peaked at the second week after onset/infection. However, the NAbs titres in the unvaccinated-infected cases reached their highest levels during the third week. Compared to those with higher levels of NAbs, those with lower levels of NAbs had no difference in viral clearance duration time (P>0.05), did exhibit higher viral load at the beginning of infection/maximum viral load of infection. NAb levels were statistically higher in the moderate cases than in the mild cases (P<0.0001). Notably, in breakthrough cases, NAb levels were highest longer than 4 months after vaccination (Delta strain: 53,118.2 U/mL), and lowest in breakthrough cases shorter than 1 month (Delta strain: 7551.2 U/mL). Cross-neutralization against the ancestral strain and the current circulating isolate (Omicron BA.5) was significantly lower than against the Delta variant in both breakthrough cases and unvaccinated-infected cases. Our study demonstrated that vaccination could induce immune responses more rapidly and greater which could be effective in controlling SARS-CoV-2.

Innovation-driven trend shaping COVID-19 vaccine development in China

Confronted with the Coronavirus disease 2019 (COVID-19) pandemic, China has become an asset in tackling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and mutation, with several innovative platforms, which provides various technical means in this persisting combat. Derived from collaborated researches, vaccines based on the spike protein of SARS-CoV-2 or inactivated whole virus are a cornerstone of the public health response to COVID-19. Herein, we outline representative vaccines in multiple routes, while the merits and plights of the existing vaccine strategies are also summarized. Likewise, new technologies may provide more potent or broader immunity and will contribute to fight against hypermutated SARS-CoV-2 variants. All in all, with the ultimate aim of delivering robust and durable protection that is resilient to emerging infectious disease, alongside the traditional routes, the discovery of innovative approach to developing effective vaccines based on virus properties remains our top priority.

Metabolic and toxicological considerations regarding CGRP mAbs and CGRP antagonists to treat migraine in COVID-19 patients: a narrative review

INTRODUCTION

Migraine pharmacological therapies targeting calcitonin gene-related peptide (CGRP), including monoclonal antibodies and gepants, have shown clinical effect and optimal tolerability. Interactions between treatments of COVID-19 and CGRP-related drugs have not been reviewed.

AREAS COVERED

An overview of CGRP, a description of the characteristics of each CGRP-related drug and its response predictors, COVID-19 and its treatment, the interactions between CGRP-related drugs and COVID-19 treatment, COVID-19 and vaccination-induced headache, and the neurological consequences of Covid-19.

EXPERT OPINION

Clinicians should be careful about using gepants for COVID-19 patients, due to the potential drug interactions with drugs metabolized via CYP3A4 cytochrome. In particular, COVID-19 treatment (especially nirmatrelvir packaged with ritonavir, as Paxlovid) should be considered cautiously. It is advisable to stop or adjust the dose (10 mg atogepant when used for episodic migraine) of gepants when using Paxlovid (except for zavegepant). CGRP moncolconal antibodies (CGRP-mAbs) do not have drug - drug interactions, but a few days' interval between a COVID-19 vaccination and the use of CGRP mAbs is recommended to allow the accurate identification of the possible adverse effects, such as injection site reaction. Covid-19- and vaccination-related headache are known to occur. Whether CGRP-related drugs would be of benefit in these circumstances is not yet known.

New-onset aplastic anemia after SARS-CoV-2 vaccination

Aplastic anemia (AA) is a rare autoimmune disease. Drugs, viruses, and radiation are among the most common etiologic factors, and most cases have immune pathophysiology. SARS-CoV-2 vaccines have been linked with rare side effects, including cases of acquired aplastic anemia. Here we review all the reported cases of new-onset AA after SARS-CoV-2 vaccination, and discuss their clinical characteristics and management. 18 patients in these case reports had a median age of 58 years. The time from vaccination to onset of aplastic anemia ranged from 1 day to 7 months, with a median of 2.5 weeks. Seventeen patients were diagnosed with severe or very severe aplastic anemia post-vaccination and all patients received standard treatments for acquired aplastic anemia. Seventeen patients achieved a complete or partial response and only 1 patient died. Aplastic anemia can be considered a very rare SARS-CoV-2 vaccine-related adverse event, although a causative relationship has not been proven. Reporting cases of such uncommon post-vaccination events could help clinicians to consider aplastic anemia when pancytopenia is observed after vaccination. The benefits of SARS-Cov-2 vaccination are established, and reports of rare events serve only to increase awareness in daily clinical practice.

Insights into the evolution of mutations in SARS-CoV-2 non-spike proteins

The COVID-19 pandemic has been driven by the emergence of SARS-CoV-2 variants with mutations across all the viral proteins. Although mutations in the spike protein have received significant attention, understanding the prevalence and potential impact of mutations in other viral proteins is essential for comprehending the evolution of SARS-CoV-2. Here, we conducted a comprehensive analysis of approximately 14 million sequences of SARS-CoV-2 deposited in the GISAID database until December 2022 to identify prevalent mutations in the non-spike proteins at the global and country levels. Additionally, we evaluated the energetics of each mutation to better understand their impact on protein stability. While the consequences of many mutations remain unclear, we discuss potential structural and functional significance of some mutations. Our study highlights the ongoing evolutionary process of SARS-CoV-2 and underscores the importance of understanding changes in non-spike proteins.

Humoral and cellular immunity against diverse SARS-CoV-2 variants

Since the outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019, the virus has rapidly spread worldwide. This has led to an unprecedented global pandemic, marked by millions of COVID-19 cases and a significant number of fatalities. Over a relatively short period, several different vaccine platforms are developed and deployed for use globally to curb the pandemic. However, the genome of SARS-CoV-2 continuously undergoes mutation and/or recombination, resulting in the emergence of several variants of concern (VOC). These VOCs can elevate viral transmission and evade the neutralizing antibodies induced by vaccines, leading to reinfections. Understanding the impact of the SARS-CoV-2 genomic mutation on viral pathogenesis and immune escape is crucial for assessing the threat of new variants to public health. This review focuses on the emergence and pathogenesis of VOC, with particular emphasis on their evasion of neutralizing antibodies. Furthermore, the memory B cell, CD4+, and CD8+ T cell memory induced by different COVID-19 vaccines or infections are discussed, along with how these cells recognize VOC. This review summarizes the current knowledge on adaptive immunology regarding SARS-CoV-2 infection and vaccines. Such knowledge may also be applied to vaccine design for other pathogens.

Development of a novel medium throughput flow-cytometry based micro-neutralisation test for SARS-CoV-2 with applications in clinical vaccine trials and antibody screening

Quantifying neutralising capacity of circulating SARS-COV-2 antibodies is critical in evaluating protective humoral immune responses generated post-infection/post-vaccination. Here we describe a novel medium-throughput flow cytometry-based micro-neutralisation test to evaluate Neutralising Antibody (NAb) responses against live SARS-CoV-2 Wild Type and Variants of Concern (VOC) in convalescent/vaccinated populations. Flow Cytometry-Based Micro-Neutralisation Test (Micro-NT) was performed in 96-well plates using clinical isolates WT-B, WT-B.1.177.18 and/or VOCs Beta and Omicron. Plasma samples (All Ireland Infectious Diseases (AIID) Cohort) were serially diluted (8 points, half-log) from 1:20 and pre-incubated with SARS-CoV-2 (1h, 37°C). Virus-plasma mixture were added onto Vero E6 or Vero E6/TMPRSS2 cells for 18h. Percentage infected cells was analysed by automated flow cytometry following trypsinisation, fixation and SARS-CoV-2 Nucleoprotein intracellular staining. Half-maximal Neutralisation Titres (NT50) were determined using non-linear regression. Our assay was compared to Plaque Reduction Neutralisation Test (PRNT) and validated against the First WHO International Standard for anti-SARS-CoV-2 immunoglobulin. Both Micro-NT and PRNT achieved comparable NT50 values. Further validation showed adequate correlation with PRNT using a panel of secondary standards of clinical convalescent and vaccinated plasma samples. We found the assay to be reproducible through measuring both repeatability and intermediate precision. Screening 190 convalescent samples and 11 COVID-19 naive controls (AIID cohort) we demonstrated that Micro-NT has broad dynamic range differentiating NT50s <1/20 to >1/5000. We could also characterise immune-escape VOC Beta and Omicron BA.5, achieving fold-reductions in neutralising capacity similar to those published. Our flow cytometry-based Micro-NT is a robust and reliable assay to quantify NAb titres, and has been selected as an endpoint in clinical trials.

Safety of Janssen Ad26.COV.S and Astra Zeneca AZD1222 COVID-19 Vaccines among Mobile Phone Users in Malawi: Findings from a National Mobile-Based Syndromic Surveillance Survey, July 2021 to December 2021

The safety profiles of the Ad26.COV2.S and AZD1222 COVID-19 vaccines have not been described in the general population in Malawi. We present self-reported adverse events (AE) following the receipt of these vaccines in Malawi as part of a national syndromic surveillance survey. We conducted phone-based syndromic surveillance surveys among adults (≥18 years) with verbal consent. We used secure tablets through random digit dialing to select mobile phone numbers and collected data electronically. Survey questions included whether the respondent had received the COVID-19 vaccines, whether they had experienced any AE following vaccination, and the severity of the AE. We used multivariable analysis to identify factors associated with self-reported AE post-COVID-19 vaccination. A total of 11,924 (36.0%) out of 33,150 respondents reported receiving at least one dose of either Ad26.COV2.S or AZD1222 between July-December 2021; of those, 65.1% were female. About 49.2% of the vaccine recipients reported at least one AE, 90.6% of which were mild, and 2.6% were severe. Higher education level and concern about the safety of COVID-19 vaccines were associated with AE self-report (Adjusted Odds Ratio [AOR] 2.63 [95% CI 1.96-3.53] and 1.44, [95% CI 1.30-1.61], respectively), while male gender and older age were associated with reduced likelihood of AE self-report (AORs 0.81, [95% CI 0.75-0.88], 0.62 [95% CI 0.50-0.77], respectively). Ad26.COV2.S and AZD1222 vaccines are well-tolerated, with primarily mild and few severe AE among adults living in Malawi. Self-reporting of AE following COVID-19 vaccination is associated with gender, age, education, and concern about the safety of the vaccines. Recognizing these associations is key when designing and implementing COVID-19 vaccination communication messages to increase vaccination coverage.

The impact of SARS-CoV-2 on healthcare workers of a large University Hospital in the Veneto Region: risk of infection and clinical presentation in relation to different pandemic phases and some relevant determinants

Aim

The aim of this study is to evaluate the incidence of SARS-CoV-2 infection and the prevalence of COVID-19-related symptoms in relation to pandemic phases and some relevant variables in a cohort of 8,029 HCWs from one of the largest Italian University Hospitals.

Methods

A single-center retrospective study was performed on data collected during SARS-CoV-2 infection surveillance of HCWs. Cox's multiple regression was performed to estimate hazard ratios of SARS-CoV-2 infection. Logistic multivariate regression was used to assess the risk of asymptomatic infections and the onset of the most frequent symptoms. All analyses were adjusted for sociodemographic and occupational factors, pandemic phases, vaccination status, and previous infections.

Results

A total of 3,760 HCWs resulted positive (2.0%-18.6% across five study phases). The total incidence rate of SARS-CoV-2 infection was 7.31 cases per 10,000 person-days, significantly lower in phase 1 and higher in phases 4 and 5, compared to phase 3. Younger HCWs, healthcare personnel, and unvaccinated subjects showed a higher risk of infection. Overall, 24.5% were asymptomatic infections, with a higher probability for men, physicians, and HCWs tested for screening, fully vaccinated, and those with previous infection. The clinical presentation changed over the phases in relation to vaccination status and the emergence of new variants.

Conclusion

The screening activities of HCWs allowed for the early detection of asymptomatic cases, limiting the epidemic clusters inside the hospital wards. SARS-CoV-2 vaccination reduced infections and symptomatic cases, demonstrating again its paramount value as a preventive tool for occupational and public health.

Evaluation of the Abdala Vaccine: Antibody and Cellular Response to the RBD Domain of SARS-CoV-2

Abdala is a recently released RBD protein subunit vaccine against SARS-CoV-2. A few countries, including Mexico, have adopted Abdala as a booster dose in their COVID-19 vaccination schemes. Despite that, most of the Mexican population has received full-scheme vaccination with platforms other than Abdala; little is known regarding Abdala's immunological features, such as its antibody production and T- and B-cell-specific response induction. This work aimed to study antibody production and the adaptive cellular response in the Mexican population that received the Abdala vaccine as a booster. We recruited 25 volunteers and evaluated their RBD-specific antibody production, T- and B-cell-activating profiles, and cytokine production. Our results showed that the Abdala vaccine increases the concentration of RBD IgG-specific antibodies. Regarding the cellular response, after challenging peripheral blood cultures with RBD, the plasmablast (CD19+CD27+CD38High) and transitional B-cell (CD19+CD21+CD38High) percentages increased significantly, while T cells showed an increased activated phenotype (CD3+CD4+CD25+CD69+ and CD3+CD4+CD25+HLA-DR+). Also, IL-2 and IFN-γ increased significantly in the supernatant of the RBD-stimulated cells. Our results suggest that Abdala vaccination, used as a booster, evokes antibody production and the activation of previously generated memory against the SARS-CoV-2 RBD domain.

Durable immunity to SARS-CoV-2 in both lower and upper airways achieved with a gorilla adenovirus (GRAd) S-2P vaccine in non-human primates

SARS-CoV-2 continues to pose a global threat, and current vaccines, while effective against severe illness, fall short in preventing transmission. To address this challenge, there's a need for vaccines that induce mucosal immunity and can rapidly control the virus. In this study, we demonstrate that a single immunization with a novel gorilla adenovirus-based vaccine (GRAd) carrying the pre-fusion stabilized Spike protein (S-2P) in non-human primates provided protective immunity for over one year against the BA.5 variant of SARS-CoV-2. A prime-boost regimen using GRAd followed by adjuvanted S-2P (GRAd+S-2P) accelerated viral clearance in both the lower and upper airways. GRAd delivered via aerosol (GRAd(AE)+S-2P) modestly improved protection compared to its matched intramuscular regimen, but showed dramatically superior boosting by mRNA and, importantly, total virus clearance in the upper airway by day 4 post infection. GrAd vaccination regimens elicited robust and durable systemic and mucosal antibody responses to multiple SARS-CoV-2 variants, but only GRAd(AE)+S-2P generated long-lasting T cell responses in the lung. This research underscores the flexibility of the GRAd vaccine platform to provide durable immunity against SARS-CoV-2 in both the lower and upper airways.

mRNA and Adenoviral Vector Vaccine Platforms Utilized in COVID-19 Vaccines: Technologies, Ecosystem, and Future Directions

New technological platforms, such as mRNA and adenoviral vector vaccines, have been utilized to develop coronavirus disease 2019 (COVID-19) vaccines. These new modalities enable rapid and flexible vaccine design and cost-effective and swift manufacturing, effectively combating pandemics caused by mutating viruses. Innovation ecosystems, including universities, startups, investors, and governments are crucial for developing these cutting-edge technologies. This review summarizes the research and development trajectory of these vaccine technologies, their investments, and the support surrounding them, in addition to the technological details of each technology. In addition, this study examines the importance of an innovation ecosystem in developing novel technologies, comparing it with the case of Japan, which has lagged behind in COVID-19 vaccine development. It also explores the direction of vaccine development in the post-COVID-19 era.

Suitability of Polymyxin B as a Mucosal Adjuvant for Intranasal Influenza and COVID-19 Vaccines

Polymyxin B (PMB) is an antibiotic that exhibits mucosal adjuvanticity for ovalbumin (OVA), which enhances the immune response in the mucosal compartments of mice. Frequent breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants indicate that the IgA antibody levels elicited by the mRNA vaccines in the mucosal tissues were insufficient for the prophylaxis of this infection. It remains unknown whether PMB exhibits mucosal adjuvanticity for antigens other than OVA. This study investigated the adjuvanticity of PMB for the virus proteins, hemagglutinin (HA) of influenza A virus, and the S1 subunit and S protein of SARS-CoV-2. BALB/c mice immunized either intranasally or subcutaneously with these antigens alone or in combination with PMB were examined, and the antigen-specific antibodies were quantified. PMB substantially increased the production of antigen-specific IgA antibodies in mucosal secretions and IgG antibodies in plasma, indicating its adjuvanticity for both HA and S proteins. This study also revealed that the PMB-virus antigen complex diameter is crucial for the induction of mucosal immunity. No detrimental effects were observed on the nasal mucosa or olfactory bulb. These findings highlight the potential of PMB as a safe candidate for intranasal vaccination to induce mucosal IgA antibodies for prophylaxis against mucosally transmitted infections.

Differences and similarities between COVID-19 related-headache and COVID-19 vaccine related-headache. A case-control study

INTRODUCTION

Headache is a frequent symptom at the acute phase of coronavirus disease 2019 (COVID-19) and also one of the most frequent adverse effects following vaccination. In both cases, headache pathophysiology seems linked to the host immune response and could have similarities. We aimed to compare the clinical phenotype and the frequency and associated onset symptoms in patients with COVID-19 related-headache and COVID-19 vaccine related-headache.

SUBJECTS AND METHODS

A case-control study was conducted. Patients with confirmed COVID-19 infection and COVID-19-vaccine recipients who experienced new-onset headache were included. A standardised questionnaire was administered, including demographic variables, prior history of headaches, associated symptoms and headache-related variables. Both groups were matched for age, sex, and prior history of headache. A multivariate regression analysis was performed.

RESULTS

A total of 238 patients fulfilled eligibility criteria (143 patients with COVID-19 related-headache and 95 subjects experiencing COVID-19 vaccine related-headache). Patients with COVID-19 related-headache exhibited a higher frequency of arthralgia, diarrhoea, dyspnoea, chest pain, expectoration, anosmia, myalgia, odynophagia, rhinorrhoea, cough, and dysgeusia. Further, patients with COVID-19 related-headache had a more prolonged daily duration of headache and described the headache as the worst headache ever experienced. Patients with COVID-19 vaccine-related headache, experienced more frequently pain in the parietal region, phonophobia, and worsening of the headache by head movements or eye movements.

CONCLUSION

Headache caused by SARS-CoV-2 infection and COVID-19 vaccination related-headache have more similarities than differences, supporting a shared pathophysiology, and the activation of the innate immune response. The main differences were related to associated symptoms.

FcγRIIa - dependent platelet activation identified in COVID-19 vaccine-induced immune thrombotic thrombocytopenia-, heparin-induced thrombocytopenia, streptokinase- and anisoylated plasminogen-streptokinase activator complex-induced platelet activation

Coronavirus disease 2019 (COVID-19), which was caused by the coronavirus - severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was globally responsible for remarkable morbidity and mortality. Several highly effective vaccines for COVID-19 were developed and disseminated worldwide within an unprecedented timescale. Rare but dangerous clotting and thrombocytopenia events, and subsequent coagulation abnormalities, have been reported after massive vaccination against SARS-CoV-2. Soon after their global rollout, reports of a morbid clinical syndrome following vaccination with adenovirus-DNA-based vaccines appeared. In the spring of 2021, reports of a novel, rare and morbid clinical syndrome, with clinically devastating and fatal complication after vaccination with adenovirus-based coronavirus vaccines (Janssen/Johnson & Johnson and Astra-Zeneca vaccines) led to a brief suspension of their use by several countries. Those complications were associated with unusual cerebral and splanchnic venous thrombosis, and circulating autoantibodies directed against anti-platelet factor 4 (PF4), a protein secreted from platelets, leading to the designation: Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT). The reported VITT incidence remains very low and does not affect the overall benefit of immunization, however, if left untreated, VITT can be debilitating or even fatal. VITT resembled specific adverse drugs' reactions that also involved the production of autoantibodies and subsequent abnormal platelet activation through platelet FcγRIIa. These unusual but well-documented drug reactions were heparin-induced thrombocytopenia (HIT), streptokinase- (SK), and anisoylated plasminogen-streptokinase activator complex- (APSAC) associated with platelet-activating antibodies. There was considerable overlapping of clinical features between VITT, COVID-19 and these adverse drugs' reactions. We review the phenomenon of VITT against the backdrop of shared and common mechanisms that underlie HIT-, SK-, and APSAC-platelet FcγRIIa-dependent platelet activation. An understanding of VITT's pathogenesis may be achieved by comparing and contrasting VITT-, HIT-, SK- and APSAC-induced platelet activation mechanisms, their respective physiopathology and similarities. Discussing these conditions in parallel provides insight into complex immunological disorders and diseases associated with abnormal hemostasis and thrombosis in particular.

Multidrug-resistant mutations to antiviral and antibody therapy in an immunocompromised patient infected with SARS-CoV-2

BACKGROUND

Antiviral and antibody therapies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being recommended for high-risk patients, but the potential for the development of multidrug-resistant mutations in immunocompromised patients is unclear.

METHODS

To investigate the treatment course in cases of prolonged viral shedding in an immunocompromised patient with SARS-CoV-2 infection, we conducted longitudinal measurements of laboratory tests, chest computed tomography (CT) image evaluations, antibody titers, and antigen levels in nasopharyngeal swabs. Furthermore, we performed whole-genome sequencing and digital PCR analysis to examine the mechanisms of drug resistance.

FINDINGS

We present a case of a 65-year-old man with a history of malignant lymphoma who was treated with multiple antiviral and antibody therapies, including sotrovimab, remdesivir, paxlovid (nirmatrelvir/ritonavir), and molnupiravir. Initially, viral antigen levels decreased after treatments. However, after the virus rebounded, the patient showed no virologic response. The viral genome analysis revealed a single Omicron subvariant (BA.1.1), which evolved within the host during the disease progression. The viruses had acquired multiple resistance mutations to nirmatrelvir (3 chymotrypsin-like protease [3CLpro] E166 A/V), sotrovimab (spike P337L and E340K), and remdesivir (RNA-dependent RNA polymerase [RdRp] V166L).

CONCLUSIONS

Our results indicate that viruses with multidrug-resistant mutations and survival fitness persist in the infected subpopulation after drug selection pressure.

FUNDING

This study was supported by the JSPS KAKENHI Early-Career Scientists 18K16292 (Y.H.), Grant-in-Aid for Scientific Research (B) 20H03668 and 23H02955 (Y.H.), the YASUDA Medical Foundation (Y.H.), the Uehara Memorial Foundation (Y.H.), the Takeda Science Foundation (Y.H.), and Kato Memorial Bioscience Foundation (Y.H.).