Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomised, double-blind, placebo-controlled, phase 2 trial

Safety and immunogenicity of CoronaVac in healthy adults: A prospective observational multicenter real-world study in Henan Province, China

Vaccination has emerged as the primar approach for managing the COVID-19 pandemic. Despite certain clinical trials reporting the safety and immunogenicity of CoronaVac, additional multicenter real-world studies are still necessary. In this study, we recruited 506 healthy volunteers who were not infected with COVID-19 or vaccinated. Each participant provided peripheral blood samples three times: prior to the first dose of vaccine, prior to the second dose, and 8 weeks following the second dose. Ultimately, 388 participants completed the entire follow-up process. No serious adverse events were observed among any of the participants. Within 1 week of vaccination, 13.4% of participants experienced systemic adverse reactions, with fatigue (5.93%) and dizziness (3.35%) being the most frequent. Although some clinical indicators, including creatinine, significantly changed after vaccination (p < 0.05), the mean of all altered indicators remained within the normal range. The positive rates of neutralizing antibodies (NAb), IgG, and IgM were 12.3%, 18.85%, and 5.24% prior to the second dose, respectively; and 57.99%, 86.34%, and 2.32% at 8 weeks following the second dose, respectively. Additionally, seven indicators, such as sex, age, and BMI, were significantly correlated with NAb (p < 0.05). Finally, a prediction model was developed based on age, monocytes, and alanine aminotransferase (ALT) with an AUC value of 87.56% in the train set and 80.71% in the test set. This study demonstrated that safety and immunogenicity of CoronaVac were good. The prediction model based on the baseline clinical characteristics prior to vaccination can help to develop more suitable vaccination strategies.

One HA stalk topping multiple heads as a novel influenza vaccine

Classic chimeric hemagglutinin (cHA) was designed to induce immune responses against the conserved stalk domain of HA. However, it is unclear whether combining more than one HA head domain onto one stalk domain is immunogenic and further induce immune responses against influenza viruses. Here, we constructed numerous novel cHAs comprising two or three fuzed head domains from different subtypes grafted onto one stalk domain, designated as cH1-H3, cH1-H7, cH1-H3-H7, and cH1-H7-H3. The three-dimensional structures of these novel cHAs were modelled using bioinformatics simulations. Structural analysis showed that the intact neutralizing epitopes were exposed in cH1-H7 and were predicted to be immunogenic. The immunogenicity of the cHAs constructs was evaluated in mice using a chimpanzee adenoviral vector (AdC68) vaccine platform. The results demonstrated that cH1-H7 expressed by AdC68 (AdC68-cH1-H7) induced the production of high levels of binding antibodies, neutralizing antibodies, and hemagglutinin inhibition antibodies against homologous pandemic H1N1, drifted seasonal H1N1, and H7N9 virus. Moreover, vaccinated mice were fully protected from a lethal challenge with the aforementioned influenza viruses. Hence, cH1-H7 cHAs with potent immunogenicity might be a potential novel vaccine to provide protection against different subtypes of influenza virus.

A pseudotyped adenovirus serotype 5 vector with serotype 49 fiber knob is an effective vector for vaccine and gene therapy applications

Adenoviruses (Ads) have demonstrated significant success as replication-deficient (RD) viral vectored vaccines, as well as broad potential across gene therapy and cancer therapy. Ad vectors transduce human cells via direct interactions between the viral fiber knob and cell surface receptors, with secondary cellular integrin interactions. Ad receptor usage is diverse across the extensive phylogeny. Commonly studied human Ad serotype 5 (Ad5), and chimpanzee Ad-derived vector "ChAdOx1" in licensed ChAdOx1 nCoV-19 vaccine, both form primary interactions with the coxsackie and adenovirus receptor (CAR), which is expressed on human epithelial cells and erythrocytes. CAR usage is suboptimal for targeted gene delivery to cells with low/negative CAR expression, including human dendritic cells (DCs) and vascular smooth muscle cells (VSMCs). We evaluated the performance of an RD Ad5 vector pseudotyped with the fiber knob of human Ad serotype 49, termed Ad5/49K vector. Ad5/49K demonstrated superior transduction of murine and human DCs over Ad5, which translated into significantly increased T cell immunogenicity when evaluated in a mouse cancer vaccine model using 5T4 tumor-associated antigen. Additionally, Ad5/49K exhibited enhanced transduction of primary human VSMCs. These data highlight the potential of Ad5/49K vector for both vascular gene therapy applications and as a potent vaccine vector.

Emerging and reemerging infectious diseases: global trends and new strategies for their prevention and control

To adequately prepare for potential hazards caused by emerging and reemerging infectious diseases, the WHO has issued a list of high-priority pathogens that are likely to cause future outbreaks and for which research and development (R&D) efforts are dedicated, known as paramount R&D blueprints. Within R&D efforts, the goal is to obtain effective prophylactic and therapeutic approaches, which depends on a comprehensive knowledge of the etiology, epidemiology, and pathogenesis of these diseases. In this process, the accessibility of animal models is a priority bottleneck because it plays a key role in bridging the gap between in-depth understanding and control efforts for infectious diseases. Here, we reviewed preclinical animal models for high priority disease in terms of their ability to simulate human infections, including both natural susceptibility models, artificially engineered models, and surrogate models. In addition, we have thoroughly reviewed the current landscape of vaccines, antibodies, and small molecule drugs, particularly hopeful candidates in the advanced stages of these infectious diseases. More importantly, focusing on global trends and novel technologies, several aspects of the prevention and control of infectious disease were discussed in detail, including but not limited to gaps in currently available animal models and medical responses, better immune correlates of protection established in animal models and humans, further understanding of disease mechanisms, and the role of artificial intelligence in guiding or supplementing the development of animal models, vaccines, and drugs. Overall, this review described pioneering approaches and sophisticated techniques involved in the study of the epidemiology, pathogenesis, prevention, and clinical theatment of WHO high-priority pathogens and proposed potential directions. Technological advances in these aspects would consolidate the line of defense, thus ensuring a timely response to WHO high priority pathogens.

Feasibility and Effectiveness of Vaccines for COVID-19: An Umbrella Review

Introduction

In January 2020, WHO declared the 2019 Coronavirus Disease (COVID-19) a pandemic. Though COVID-19 vaccines are recommended, ongoing surveillance is crucial due to potential unforeseen events. Evaluation of long-term effectiveness and safety and addressing emerging variants are vital. This study integrates systematic reviews to assess COVID-19 vaccine efficacy, immunogenicity, and safety comprehensively.

Methods

This study was an umbrella review study on the feasibility and effectiveness of vaccines for COVID-19. We conducted a comprehensive search in PubMed, Web of Sciences, and Scopus, using MeSH terms and keywords related to COVID-19 vaccines. Inclusion criteria comprised peer-reviewed systematic reviews and meta-analyses in English, focusing on feasibility and effectiveness. Exclusion criteria targeted non-systematic reviews exclusively on vaccine safety and duplicates. Two independent reviewers screened and resolved discrepancies. Data extraction included key details. Methodological quality was assessed using the ROBIS tool. Data synthesis involves narrative and, if applicable, quantitative synthesis (meta-analysis). Reporting followed PRISMA guidelines.

Results

A total of 32 systematic reviews were included in the study, of which 20 also conducted a meta-analysis. The studies investigated in the included reviews ranged from 7 to 74. The included articles were conducted in various countries around the globe. The findings indicated that COVID-19 vaccines are generally safe and effective for individuals with various medical conditions. The overall risk of bias for the included studies was assessed as low risk.

Conclusion

The study outcomes indicated that mRNA vaccines exhibit a higher incidence of adverse events but demonstrate greater efficacy. Conversely, inactivated and protein subunit vaccines are safer but exhibit lower efficiency. Moreover, the vaccine is considered safe for individuals with specific conditions such as inflammatory bowel disease, solid organ transplant recipients, children, pregnant individuals, and those with hematologic problems. Ultimately, the acceptance of the COVID-19 vaccine among individuals is influenced by various factors, including geographic, socioeconomic, and pandemic-related considerations.

Bioproduction and immunogenic evaluation of SARS-CoV-2 prototype vaccine in silkworm BmN cells

COVID-19, caused by the novel coronavirus SARS-CoV-2, has presented a significant challenge to global health, security, and the economy. Vaccination is considered a crucial measure in preventing virus transmission. The silkworm bioreactor has gained widespread usage in antigen presentation, monoclonal antibody preparation, and subunit vaccine development due to its safety, efficiency, convenience, and cost-effectiveness. In this study, we employed silkworm BmN cells and the silkworm MultiBac multigene co-expression system to successfully produce two prototype vaccines: a recombinant baculovirus vector vaccine (NPV) co-displaying the SARS-CoV-2 virus capsid protein and a capsid protein virus-like particle (VLP) vaccine. Following the purification of these vaccines, we immunized BALB/c mice to evaluate their immunogenicity. Our results demonstrated that both VLP and NPV prototype vaccines effectively elicited robust immune responses in mice. However, when equal inoculation doses between groups were compared, the recombinant NPV vaccine exhibited significantly higher serum antibody titers and increased expression of spleen cytokines and lymphocyte immune regulatory factors compared to the VLP group. These results suggested an increased immune efficacy of the recombinant NPV vaccine. Conversely, the VLP prototype vaccine displayed more pronounced effects on lymphocyte cell differentiation induction. This study successfully constructed two distinct morphological recombinant vaccine models and systematically elucidated their differences in humoral immune response and lymphocyte differentiation rate. Furthermore, it has fully harnessed the immense potential of silkworm bioreactors for vaccine research and development, providing valuable technical insights for studying mutated viruses like coronaviruses.

Intranasal HD-Ad-FS vaccine induces systemic and airway mucosal immunities against SARS-CoV-2 and systemic immunity against SARS-CoV-2 variants in mice and hamsters

The outbreak of coronavirus disease 19 (COVID-19) has highlighted the demand for vaccines that are safe and effective in inducing systemic and airway mucosal immunity against the aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we developed a novel helper-dependent adenoviral vector-based COVID-19 mucosal vaccine encoding a full-length SARS-CoV-2 spike protein (HD-Ad-FS). Through intranasal immunization (single-dose and prime-boost regimens), we demonstrated that the HD-Ad-FS was immunogenic and elicited potent systemic and airway mucosal protection in BALB/c mice, transgenic ACE2 (hACE2) mice, and hamsters. We detected high titers of neutralizing antibodies (NAbs) in sera and bronchoalveolar lavages (BALs) in the vaccinated animals. High levels of spike-specific secretory IgA (sIgA) and IgG were induced in the airway of the vaccinated animals. The single-dose HD-Ad-FS elicited a strong immune response and protected animals from SARS-CoV-2 infection. In addition, the prime-boost vaccination induced cross-reactive serum NAbs against variants of concern (VOCs; Beta, Delta, and Omicron). After challenge, VOC infectious viral particles were at undetectable or minimal levels in the lower airway. Our findings highlight the potential of airway delivery of HD-Ad-FS as a safe and effective vaccine platform for generating mucosal protection against SARS-CoV-2 and its VOCs.

What Is the Economic Benefit of Annual COVID-19 Vaccination From the Adult Individual Perspective?

BACKGROUND

With coronavirus disease 2019 (COVID-19) vaccination no longer mandated by many businesses/organizations, it is now up to individuals to decide whether to get any new boosters/updated vaccines going forward.

METHODS

We developed a Markov model representing the potential clinical/economic outcomes from an individual perspective in the United States of getting versus not getting an annual COVID-19 vaccine.

RESULTS

For an 18-49 year old, getting vaccinated at its current price ($60) can save the individual on average $30-$603 if the individual is uninsured and $4-$437 if the individual has private insurance, as long as the starting vaccine efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is ≥50% and the weekly risk of getting infected is ≥0.2%, corresponding to an individual interacting with 9 other people in a day under Winter 2023-2024 Omicron SARS-CoV-2 variant conditions with an average infection prevalence of 10%. For a 50-64 year old, these cost-savings increase to $111-$1278 and $119-$1706 for someone without and with insurance, respectively. The risk threshold increases to ≥0.4% (interacting with 19 people/day), when the individual has 13.4% preexisting protection against infection (eg, vaccinated 9 months earlier).

CONCLUSIONS

There is both clinical and economic incentive for the individual to continue to get vaccinated against COVID-19 each year.

Recent Advances in Oral Vaccines for Animals

Compared to traditional injected vaccines, oral vaccines offer significant advantages for the immunization of livestock and wildlife due to their ease of use, high compliance, improved safety, and potential to stimulate mucosal immune responses and induce systemic immunity against pathogens. This review provides an overview of the delivery methods for oral vaccines, and the factors that influence their immunogenicity. We also highlight the global progress and achievements in the development and use of oral vaccines for animals, shedding light on potential future applications in this field.

Vaccine delivery systems and administration routes: Advanced biotechnological techniques to improve the immunization efficacy

Since the first use of vaccine tell the last COVID-19 pandemic caused by spread of SARS-CoV-2 worldwide, the use of advanced biotechnological techniques has accelerated the development of different types and methods for immunization. The last pandemic showed that the nucleic acid-based vaccine, especially mRNA, has an advantage in terms of development time; however, it showed a very critical drawback namely, the higher costs when compared to other strategies, and its inability to protect against new variants. This showed the need of more improvement to reach a better delivery and efficacy. In this review we will describe different vaccine delivery systems including, the most used viral vector, and also variable strategies for delivering of nucleic acid-based vaccines especially lipid-based nanoparticles formulation, polymersomes, electroporation and also the new powerful tools for the delivery of mRNA, which is based on the use of cell-penetrating peptides (CPPs). Additionally, we will also discuss the main challenges associated with each system. Finlay, the efficacy and safety of the vaccines depends not only on the formulations and delivery systems, but also the dosage and route of administration are also important players, therefore we will see the different routes for the vaccine administration including traditionally routes (intramuscular, Transdermal, subcutaneous), oral inhalation or via nasal mucosa, and will describe the advantages and disadvantage of each administration route.

Passive infusion of an S2-Stem broadly neutralizing antibody protects against SARS-CoV-2 infection and lower airway inflammation in rhesus macaques

The continued evolution of SARS-CoV-2 variants capable of subverting vaccine and infection-induced immunity suggests the advantage of a broadly protective vaccine against betacoronaviruses (β-CoVs). Recent studies have isolated monoclonal antibodies (mAbs) from SARS-CoV-2 recovered-vaccinated donors capable of neutralizing many variants of SARS-CoV-2 and other β-CoVs. Many of these mAbs target the conserved S2 stem region of the SARS-CoV-2 spike protein, rather the receptor binding domain contained within S1 primarily targeted by current SARS-CoV-2 vaccines. One of these S2-directed mAbs, CC40.8, has demonstrated protective efficacy in small animal models against SARS-CoV-2 challenge. As the next step in the pre-clinical testing of S2-directed antibodies as a strategy to protect from SARS-CoV-2 infection, we evaluated the in vivo efficacy of CC40.8 in a clinically relevant non-human primate model by conducting passive antibody transfer to rhesus macaques (RM) followed by SARS-CoV-2 challenge. CC40.8 mAb was intravenously infused at 10mg/kg, 1mg/kg, or 0.1 mg/kg into groups (n=6) of RM, alongside one group that received a control antibody (PGT121). Viral loads in the lower airway were significantly reduced in animals receiving higher doses of CC40.8. We observed a significant reduction in inflammatory cytokines and macrophages within the lower airway of animals infused with 10mg/kg and 1mg/kg doses of CC40.8. Viral genome sequencing demonstrated a lack of escape mutations in the CC40.8 epitope. Collectively, these data demonstrate the protective efficiency of broadly neutralizing S2-targeting antibodies against SARS-CoV-2 infection within the lower airway while providing critical preclinical work necessary for the development of pan-β-CoV vaccines.

SARS-CoV-2 Vaccines: The Advantage of Mucosal Vaccine Delivery and Local Immunity

Immunity against respiratory pathogens is often short-term, and, consequently, there is an unmet need for the effective prevention of such infections. One such infectious disease is coronavirus disease 19 (COVID-19), which is caused by the novel Beta coronavirus SARS-CoV-2 that emerged around the end of 2019. The World Health Organization declared the illness a pandemic on 11 March 2020, and since then it has killed or sickened millions of people globally. The development of COVID-19 systemic vaccines, which impressively led to a significant reduction in disease severity, hospitalization, and mortality, contained the pandemic's expansion. However, these vaccines have not been able to stop the virus from spreading because of the restricted development of mucosal immunity. As a result, breakthrough infections have frequently occurred, and new strains of the virus have been emerging. Furthermore, SARS-CoV-2 will likely continue to circulate and, like the influenza virus, co-exist with humans. The upper respiratory tract and nasal cavity are the primary sites of SARS-CoV-2 infection and, thus, a mucosal/nasal vaccination to induce a mucosal response and stop the virus' transmission is warranted. In this review, we present the status of the systemic vaccines, both the approved mucosal vaccines and those under evaluation in clinical trials. Furthermore, we present our approach of a B-cell peptide-based vaccination applied by a prime-boost schedule to elicit both systemic and mucosal immunity.

Virus-Mimetic Extracellular-Vesicle Vaccine Boosts Systemic and Mucosal Immunity via Immune Recruitment

Mucosal vaccines can prevent viruses from infecting the respiratory mucosa, rather than only curtailing infection and protecting against the development of disease symptoms. The SARS-CoV-2 spike receptor-binding domain (RBD) is a compelling vaccine target but is undermined by suboptimal mucosal immunogenicity. Here, we report a SARS-CoV-2-mimetic extracellular-vesicle vaccine developed using genetic engineering and dendritic cell membrane budding. After mucosal immunization, the vaccine recruits antigen-presenting cells rapidly initiating a strong innate immune response. Notably, it obviates the need for adjuvants and can induce germinal center formation through both intramuscular and intratracheal vaccination. It not only elicits high levels of RBD-specific antibodies but also stimulates extensive cellular immunity in the respiratory mucosa. A sequential immunization strategy, starting with an intramuscular injection followed by an intratracheal booster, significantly bolsters mucosal immunity with high levels of IgA and tissue-resident memory T cell responses, thereby establishing a formidable defense against pseudovirus infection.

Gene editing therapy for cardiovascular diseases

The development of gene editing tools has been a significant area of research in the life sciences for nearly 30 years. These tools have been widely utilized in disease detection and mechanism research. In the new century, they have shown potential in addressing various scientific challenges and saving lives through gene editing therapies, particularly in combating cardiovascular disease (CVD). The rapid advancement of gene editing therapies has provided optimism for CVD patients. The progress of gene editing therapy for CVDs is a comprehensive reflection of the practical implementation of gene editing technology in both clinical and basic research settings, as well as the steady advancement of research and treatment of CVDs. This article provides an overview of the commonly utilized DNA-targeted gene editing tools developed thus far, with a specific focus on the application of these tools, particularly the clustered regularly interspaced short palindromic repeat/CRISPR-associated genes (Cas) (CRISPR/Cas) system, in CVD gene editing therapy. It also delves into the challenges and limitations of current gene editing therapies, while summarizing ongoing research and clinical trials related to CVD. The aim is to facilitate further exploration by relevant researchers by summarizing the successful applications of gene editing tools in the field of CVD.

SARS-CoV-2 Vaccination Improves Semen Quality in Men Recovered From COVID-19: A Retrospective Cohort Study

Coronavirus disease 2019 (COVID-19) has been reported to decrease semen quality in reproductive-age men. Semen quality in vaccinated men after SARS-CoV-2 infection remains unclear. We recruited reproductive-age Chinese men scheduled for COVID-19 vaccination from December 2022 to March 2023. Among 1,639 vaccinated participants, an upward trend was found in sperm concentration (p < .001), progressive motility (p < .001), total motility (p < .001), total motile sperm count (TMSC) (p < .001), and normal morphology (p = .01) over time following COVID-19 recovery. Among men with an SARS-CoV-2 infection that lasted less than 30 days, men who received an inactivated vaccine booster had higher sperm progressive (p = .006) and total motility (p = .005) as well as TMSC (p = .008) than those without a booster vaccine, whereas no difference was found in semen parameters among men who received a recombinant protein vaccine. Similarly, an upward trend in semen quality was found among 122 men who provided semen samples before and after COVID-19. Higher risks of asthenozoospermia (odds ratio [OR] = 2.23, p < .001) and teratozoospermia (OR = 2.09, p = .03) were found among men who had an SARS-CoV-2 infection that lasted less than 30 days than among those without COVID-19. Collectively, after receiving SARS-CoV-2 vaccination, adverse but reversible semen parameters were observed in men recovering from COVID-19 over time. Recombinant protein vaccines and inactivated vaccine boosters should be recommended to all reproductive-age men.

The impact of comorbidity status in COVID-19 vaccines effectiveness before and after SARS-CoV-2 omicron variant in northeastern Mexico: a retrospective multi-hospital study

Introduction

The end of the coronavirus disease 2019 (COVID-19) pandemic has been declared by the World Health Organization on May 5, 2023. Several vaccines were developed, and new data is being published about their effectiveness. However, the clinical trials for the vaccines were performed before the Omicron variant appeared and there are population groups where vaccine effectiveness still needs to be tested. The overarching goal of the present study was to analyze the effects of COVID-19 vaccination before and after the Omicron variant in patients considering comorbidities in a population from Nuevo Leon, Mexico.

Methods

Epidemiological COVID-19 data from the Mexican Social Security Institute were collected from 67 hospitals located in northeastern Mexico, from July 2020 to May 2023, and a total of 669,393 cases were compiled, 255,819 reported a SARS-CoV-2 positive reverse transcription quantitative polymerase chain reaction (RT-qPCR) test or a positive COVID-19 antigen rapid test.

Results

Before Omicron (BO, 2020-2021), after 14 days of two doses of COVID-19 vaccine, BNT162b2 and ChAdOx1 vaccines were effective against infection in non-comorbid and all comorbid subgroups, whereas after Omicron (AO, 2022- 2023) there was no significant effectiveness against infection with none of the vaccines. Regarding hospitalization BO, BNT162b2, ChAdOx1, CoronaVac and mRNA-1273 significantly protected non-comorbid patients whereas BNT162b2, ChAdOx1, and mRNA-1273, protected all comorbid subgroups against hospitalization. AO, BNT162b2, ChAdOx1, CoronaVac and mRNA-1273 were effective against hospitalization in non-comorbid patients whereas for most comorbid subgroups BNT162b2, ChAdOx1 and CoronaVac were effective against hospitalization. Non-comorbid patients were protected against death as an outcome of COVID-19 during the BO period with most vaccines whereas a reduction in effectiveness was observed AO with mRNA-1273 vaccines in patients with hypertension, and diabetes mellitus.

Discussion

BO, COVID-19 vaccines were effective against infection, hospitalization, and death whereas AO, COVID-19 vaccines failed to protect the population from COVID-19 infection. A varying effectiveness against hospitalization and death is observed AO.

Effect of Prior ChAdOx1 COVID-19 Immunisation on T-Cell Responses to ChAdOx1-HBV

There are varying data concerning the effect of prior anti-vector immunity on the T-cell response induced by immunisation with an identical vectored vaccine containing a heterologous antigen insert. To determine whether prior exposure to ChAdOx1-SARS-CoV2 immunisation (Vaxzevria®) impacts magnitudes of antigen-specific T-cell responses elicited by subsequent administration of the same viral vector (encoding HBV antigens, ChAdOx1-HBV), healthy volunteers that had received Vaxzevria® (n = 15) or the Pfizer or Moderna mRNA COVID-19 vaccine (n = 11) between 10 and 18 weeks prior were recruited to receive a single intramuscular injection of ChAdOx1-HBV. Anti-ChAdOx1-neutralising antibody titers were determined, and vector or insert-specific T-cell responses were measured by a gamma-interferon ELISpot and intracellular cytokine staining (ICS) assay using multiparameter flow cytometry. Participants were followed for three months after the ChAdOx1-HBV injection, which was well-tolerated, and no dropouts occurred. The baseline ChAdOx1 neutralisation titers were higher in the Vaxzevria® cohort (median of 848) than in the mRNA cohort (median of 25). T-cell responses to HBV antigens, measured by ELISpot, were higher on day 28 in the mRNA group (p = 0.013) but were similar between groups on day 84 (p = 0.441). By ICS, these differences persisted at the last time point. There was no clear correlation between the baseline responses to the adenoviral hexon and the subsequent ELISpot responses. As vaccination within 3 months using the same viral vector backbone affected the insert-specific T-cell responses, a greater interval after prior adenoviral immunisation using heterologous antigens may be warranted in settings in which these cells play critical roles.

The investigation of the dynamics of changes in neutralizing antibody titers against type 5 adenovirus in the context of vaccination against a new coronavirus infection

This research focuses on analyzing the dynamics of neutralizing antibody (nAbs) titers against type 5 adenovirus (Ad5) in the adult population of Russia following vaccination against the novel coronavirus infection with recombinant adenovirus type-5 COVID-19 vaccine (CanSino Biologics, China). The impact of the Ad5 vector on nAb titers was investigated using 302 blood serum samples from individuals who received a single dose of the Ad5-nCoV vector vaccine. The research revealed that 33.8% of adults in Russia had pre-existing anti-Ad5 nAbs before the pandemic. Notably, 40% of vaccinated individuals did not exhibit an increase in nAbs titers upon receiving the Ad5-based vaccine. However, in the group with no or low titers of anti-Ad5 nAbs (1:10-1:40), a significant 8-16-fold increase in nAb titers to Ad5 was observed.

Cutaneous adverse reactions associated with COVID-19 vaccines: Current evidence and potential immune mechanisms

As the number of vaccinated individuals has increased, there have been increasing reports of cutaneous hypersensitivity reactions. The main COVID-19 vaccines administered include messenger ribonucleic acid vaccines, non-replicating viral vector vaccines, inactivated whole-virus vaccines, and protein-based vaccines. These vaccines contain active components such as polyethylene glycol, polysorbate 80, aluminum, tromethamine, and disodium edetate dihydrate. Recent advances in understanding the coordination of inflammatory responses by specific subsets of lymphocytes have led to a new classification based on immune response patterns. We categorize these responses into four patterns: T helper (Th)1-, Th2-, Th17/22-, and Treg-polarized cutaneous inflammation after stimulation of COVID-19 vaccines. Although the association between COVID-19 vaccination and these cutaneous adverse reactions remains controversial, the occurrence of rare dermatoses and their short intervals suggest a possible relationship. Despite the potential adverse reactions, the administration of COVID-19 vaccines is crucial in the ongoing battle against severe acute respiratory syndrome coronavirus 2.

Construction of cytomegalovirus promoter-driven gene expression system in Laodelphax striatellus

The small brown planthopper (SBPH, Laodelphax striatellus) is a significant rice pest, responsible for transmitting rice stripe virus (RSV) in a persistent and propagative manner. RSV is one of the most detrimental rice viruses, causing rice stripe disease, which results in considerable loss of rice grain yield. While RNA interference and gene knockout techniques have enabled gene downregulation in SBPH, no system currently exists for the overexpression of endogenous or exogenous genes. Consequently, the development of a protein expression system for SBPH is imperative to serve as a technical foundation for pest control and gene function investigations. This study aimed to construct an expression vector using the promoter of the constitutive-expressed tubulin gene of SBPH, and promoter of human cytomegalovirus (CMV). Fluorescence experiments demonstrated that both tubulin and CMV promoter could drive green fluorescent protein (GFP) expression in SBPH, and could also facilitate the expression of a nucleocapsid protein (NP) -GFP fusion protein containing viral NP with comparable efficiency. Through expression vector optimization, we have identified that the 3 tandem CMV promoters display a significantly higher promoter activity compared with both the 2 tandem CMV promoters and the single CMV promoter. In addition, the incorporation of Star polycation nanoparticles significantly enhanced the expression efficiency in SBPH. These results provide a promising technical platform for investigating gene functions in SBPH.

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

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

A measles-vectored vaccine candidate expressing prefusion-stabilized SARS-CoV-2 spike protein brought to phase I/II clinical trials: candidate selection in a preclinical murine model

In the early COVID-19 pandemic with urgent need for countermeasures, we aimed at developing a replicating viral vaccine using the highly efficacious measles vaccine as vector, a promising technology with prior clinical proof of concept. Building on our successful pre-clinical development of a measles virus (MV)-based vaccine candidate against the related SARS-CoV, we evaluated several recombinant MV expressing codon-optimized SARS-CoV-2 spike glycoprotein. Candidate V591 expressing a prefusion-stabilized spike through introduction of two proline residues in HR1 hinge loop, together with deleted S1/S2 furin cleavage site and additional inactivation of the endoplasmic reticulum retrieval signal, was the most potent in eliciting neutralizing antibodies in mice. After single immunization, V591 induced similar neutralization titers as observed in sera of convalescent patients. The cellular immune response was confirmed to be Th1 skewed. V591 conferred long-lasting protection against SARS-CoV-2 challenge in a murine model with marked decrease in viral RNA load, absence of detectable infectious virus loads, and reduced lesions in the lungs. V591 was furthermore efficacious in an established non-human primate model of disease (see companion article [S. Nambulli, N. Escriou, L. J. Rennick, M. J. Demers, N. L. Tilston-Lunel et al., J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23]). Thus, V591 was taken forward into phase I/II clinical trials in August 2020. Unexpected low immunogenicity in humans (O. Launay, C. Artaud, M. Lachâtre, M. Ait-Ahmed, J. Klein et al., eBioMedicine 75:103810, 2022, https://doi.org/10.1016/j.ebiom.2021.103810) revealed that the underlying mechanisms for resistance or sensitivity to pre-existing anti-measles immunity are not yet understood. Different hypotheses are discussed here, which will be important to investigate for further development of the measles-vectored vaccine platform.IMPORTANCESARS-CoV-2 emerged at the end of 2019 and rapidly spread worldwide causing the COVID-19 pandemic that urgently called for vaccines. We developed a vaccine candidate using the highly efficacious measles vaccine as vector, a technology which has proved highly promising in clinical trials for other pathogens. We report here and in the companion article by Nambulli et al. (J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23) the design, selection, and preclinical efficacy of the V591 vaccine candidate that was moved into clinical development in August 2020, 7 months after the identification of SARS-CoV-2 in Wuhan. These unique in-human trials of a measles vector-based COVID-19 vaccine revealed insufficient immunogenicity, which may be the consequence of previous exposure to the pediatric measles vaccine. The three studies together in mice, primates, and humans provide a unique insight into the measles-vectored vaccine platform, raising potential limitations of surrogate preclinical models and calling for further refinement of the platform.

Persistence of COVID-19 Human Milk Antibodies After Maternal COVID-19 Vaccination: Systematic Review and Meta-Regression Analysis

The World Health Organization (WHO) declared COVID-19 a pandemic. The Centers for Disease Control and Prevention (CDC), WHO, and American College of Obstetricians and Gynecologists (ACOG) recommend vaccination of pregnant and lactating women, aiming to protect both mothers and their infants through transplacental and human milk antibody transmission. This study aims to assess the quantity of antibodies in human milk and determine the effect of time, vaccine type, and dose on antibody level. Single-arm prospective observational studies reporting the COVID-19-specific antibody level in human milk after COVID-19 vaccination during pregnancy or lactation were included. PubMed, Scopus, Cochrane, EBSCO, and Web of Science were searched from December 2019 to November 22, 2022. Data were extracted in a uniform Google sheet. A total of 2657 studies were identified. After the removal of duplicates and screening, 24 studies were included in the systematic review and meta-regression. Human milk COVID-19-specific antibody levels increased with subsequent vaccine doses, as reflected by a positive relationship for the second (coefficient=0.91, P-value 0.043 for IgA and coefficient=1.77, P-value 0.009 for IgG) and third (coefficient=1.23, P-value 0.0029 for IgA and coefficient=3.73, P-value 0.0068 for IgG) doses. The antibody level exhibited a weak positive relationship with the follow-up time (coefficient=0.13, P-value 0.0029 for IgA and coefficient=0.18, P-value 0.016 for IgG). Only one of the 38 infants showed detectable COVID-19 IgM and IgA antibody levels in their blood. There was an increase in the neutralizing activity of COVID-19 antibodies in human milk following the COVID-19 vaccination. From the analysis of published data, we found high positive levels of antibodies in human milk that increased with subsequent doses. Additionally, the human milk antibodies exhibit a positive neutralizing effect. Only one infant had detectable COVID-19 IgM+IgA antibodies in the blood. Further research is needed to discuss infant protection through a mother's vaccination.

Mucosal vaccines for viral diseases: Status and prospects

Virus-associated infectious diseases are highly detrimental to human health and animal husbandry. Among all countermeasures against infectious diseases, prophylactic vaccines, which developed through traditional or novel approaches, offer potential benefits. More recently, mucosal vaccines attract attention for their extraordinary characteristics compared to conventional parenteral vaccines, particularly for mucosal-related pathogens. Representatively, coronavirus disease 2019 (COVID-19), a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), further accelerated the research and development efforts for mucosal vaccines by thoroughly investigating existing strategies or involving novel techniques. While several vaccine candidates achieved positive progresses, thus far, part of the current COVID-19 mucosal vaccines have shown poor performance, which underline the need for next-generation mucosal vaccines and corresponding platforms. In this review, we summarized the typical mucosal vaccines approved for humans or animals and sought to elucidate the underlying mechanisms of these successful cases. In addition, mucosal vaccines against COVID-19 that are in human clinical trials were reviewed in detail since this public health event mobilized all advanced technologies for possible solutions. Finally, the gaps in developing mucosal vaccines, potential solutions and prospects were discussed. Overall, rational application of mucosal vaccines would facilitate the establishing of mucosal immunity and block the transmission of viral diseases.

Neutralizing antibody responses to the Delta variant of SARS-CoV-2 following vaccination with Ad5-nCoV (CanSino) in the Mexican population

During the COVID-19 pandemic, the Ad5-nCoV vaccine was applied to the Mexican population before the WHO approved it. In a transversal study, we compare the CanSino vaccine efficacy and a natural SARS-CoV-2 infection in eliciting neutralizing antibodies against the SARS-CoV-2 Delta variant in Guadalajara, Mexico. Participants between 30-60 years were included in the study and classified into three groups: 1) Natural immunity (unvaccinated), 2) Vaccine-induced immunity (vaccinated individuals without a COVID-19 history), and 3) Natural immunity + vaccine-induced immunity. These groups were matched by age and gender. We assessed the ability of individuals' serum to neutralize the Delta variant and compared the results of the different groups using a neutralization test followed by plaque-forming units. Results showed that 39% of individuals' serum with a history of COVID-19 (natural immunity, Group 1) could not neutralize the Delta variant, compared to 33% in vaccinated individuals without COVID-19 (vaccine immunity, Group 2). In contrast, only 7% of vaccinated individuals with a history of COVID-19 (natural + vaccine immunities) could not neutralize the Delta variant. We concluded that the effectiveness of the Ad5-nCoV vaccine to induce neutralizing antibodies against the Delta variant is comparable to that of natural infection (61% vs. 67%). However, in individuals with both forms of immunity (Group 3), it increased to 93%. Based on these results, despite the Ad5-nCoV vaccine originally being designed as a single-dose regimen, it could be recommended that even those who have recovered from COVID-19 should consider vaccination to boost their immunity against this variant.

Clonal structure and the specificity of vaccine-induced T cell response to SARS-CoV-2 Spike protein

Adenovirus vaccines, particularly the COVID-19 Ad5-nCoV adenovirus vaccine, have emerged as promising tools in the fight against infectious diseases. In this study, we investigated the structure of the T cell response to the Spike protein of the SARS-CoV-2 virus used in the COVID-19 Ad5-nCoV adenoviral vaccine in a phase 3 clinical trial (NCT04540419). In 69 participants, we collected peripheral blood samples at four time points after vaccination or placebo injection. Sequencing of T cell receptor repertoires from Spike-stimulated T cell cultures at day 14 from 17 vaccinated revealed a more diverse CD4+ T cell repertoire compared to CD8+. Nevertheless, CD8+ clonotypes accounted for more than half of the Spike-specific repertoire. Our longitudinal analysis showed a peak T cell response at day 14, followed by a decline until month 6. Remarkably, multiple T cell clonotypes persisted for at least 6 months after vaccination, as demonstrated by ex vivo stimulation. Examination of CDR3 regions revealed homologous sequences in both CD4+ and CD8+ clonotypes, with major CD8+ clonotypes sharing high similarity with annotated sequences specific for the NYNYLYRLF peptide, suggesting potential immunodominance. In conclusion, our study demonstrates the immunogenicity of the Ad5-nCoV adenoviral vaccine and highlights its ability to induce robust and durable T cell responses. These findings provide valuable insight into the efficacy of the vaccine against COVID-19 and provide critical information for ongoing efforts to control infectious diseases.

The Biodistribution of Replication-Defective Simian Adenovirus 1 Vector in a Mouse Model

The administration route affects the biodistribution of a gene transfer vector and the expression of a transgene. A simian adenovirus 1 vector carrying firefly luciferase and GFP reporter genes (SAdV1-GFluc) were constructed, and its biodistribution was investigated in a mouse model by bioluminescence imaging and virus DNA tracking with real-time PCR. Luciferase activity and virus DNA were mainly found in the liver and spleen after the intravenous administration of SAdV1-GFluc. The results of flow cytometry illustrated that macrophages in the liver and spleen as well as hepatocytes were the target cells. Repeated inoculation was noneffective because of the stimulated serum neutralizing antibodies (NAbs) against SAdV-1. A transient, local expression of low-level luciferase was detected after intragastric administration, and the administration could be repeated without compromising the expression of the reporter gene. Intranasal administration led to a moderate, constant expression of a transgene in the whole respiratory tract and could be repeated one more time without a significant increase in the NAb titer. An immunohistochemistry assay showed that respiratory epithelial cells and macrophages in the lungs were transduced. High luciferase activity was restricted at the injection site and sustained for a week after intramuscular administration. A compromised transgene expression was observed after a repeated injection. When these mice were intramuscularly injected for a third time with the human adenovirus 5 (HAdV-5) vector carrying a luciferase gene, the luciferase activity recovered and reached the initial level, suggesting that the sequential use of SAdV-1 and HAdV-5 vectors was practicable. In short, the intranasal inoculation or intramuscular injection may be the preferred administration routes for the novel SAdV-1 vector in vaccine development.

Enhanced Immunogenicity and Protective Effects against SARS-CoV-2 Following Immunization with a Recombinant RBD-IgG Chimeric Protein

The unprecedented global impact caused by SARS-CoV-2 imposed huge health and economic challenges, highlighting the urgent need for safe and effective vaccines. The receptor-binding domain (RBD) of SARS-CoV-2 is the major target for neutralizing antibodies and for vaccine formulations. Nonetheless, the low immunogenicity of the RBD requires the use of alternative strategies to enhance its immunological properties. Here, we evaluated the use of a subunit vaccine antigen generated after the genetic fusing of the RBD with a mouse IgG antibody. Subcutaneous administration of RBD-IgG led to the extended presence of the protein in the blood of immunized animals and enhanced RBD-specific IgG titers. Furthermore, RBD-IgG immunized mice elicited increased virus neutralizing antibody titers, measured both with pseudoviruses and with live original (Wuhan) SARS-CoV-2. Immunized K18-hACE2 mice were fully resistant to the lethal challenge of the Wuhan SARS-CoV-2, demonstrated by the control of body-weight loss and virus loads in their lungs and brains. Thus, we conclude that the genetic fusion of the RBD with an IgG molecule enhanced the immunogenicity of the antigen and the generation of virus-neutralizing antibodies, supporting the use of IgG chimeric antigens as an approach to improve the performance of SARS-CoV-2 subunit vaccines.

Harnessing adenovirus in cancer immunotherapy: evoking cellular immunity and targeting delivery in cell-specific manner

Recombinant adenovirus (rAd) regimens, including replication-competent oncolytic adenovirus (OAV) and replication-deficient adenovirus, have been identified as potential cancer therapeutics. OAV presents advantages such as selective replication, oncolytic efficacy, and tumor microenvironment (TME) remodeling. In this perspective, the principles and advancements in developing OAV toolkits are reviewed. The burgeoning rAd may dictate efficacy of conventional cancer therapies as well as cancer immunotherapies, including cancer vaccines, synergy with adoptive cell therapy (ACT), and TME reshaping. Concurrently, we explored the potential of rAd hitchhiking to adoptive immune cells or stem cells, highlighting how this approach facilitates synergistic interactions between rAd and cellular therapeutics at tumor sites. Results from preclinical and clinical trials in which immune and stem cells were infected with rAd have been used to address significant oncological challenges, such as postsurgical residual tumor tissue and metastatic tissue. Briefly, rAd can eradicate tumors through various mechanisms, resulting from tumor immunogenicity, reprogramming of the TME, enhancement of cellular immunity, and effective tumor targeting. In this context, we argue that rAd holds immense potential for enhancing cellular immunity and synergistically improving antitumor effects in combination with novel cancer immunotherapies.

Global Prevalence of Preexisting Antibodies against Human Adenoviruses, Surveyed from 1962 to 2021

BACKGROUND

Human adenoviruses (HAdVs) are extensively used as vectors for vaccines development and cancer therapy. People who already have antibodies against HAdVs, on the other hand, would have an impact on the preventative or therapeutic effect. This review focuses primarily on the prevalence of pre-existing antibodies against HAdVs in distinct geographical populations.

SUMMARY

After screening, 64 studies from 31 countries between 1962 and 2021 were selected, totaling 39,427 samples. The total prevalence of preexisting antibodies to HAdVs varied by country or location, ranging from 2.00 to 95.70%. Southeast Asia had the highest prevalence (54.57%) while Europe had the lowest (18.17%). The prevalence in practically all developing nations was higher than in developed nations. Adults have a greater frequency than children and newborns in most nations. The primary HAdV antibody types varied by country. Adults in China, the USA, the United Kingdom, and Belgium had the lowest prevalence of preexisting antibodies against HAdV55, HAdV37, HAdV8, and HAdV36, respectively. Children in the USA, China, the United Kingdom, and Japan had the lowest rates of HAdV48, HAdV11, HAdV8, and HAdV40. The frequency of antibodies differed significantly between military and civilian groups.

KEY MESSAGES

Preexisting antibodies against various types of HAdVs differed greatly throughout worldwide populations. Future development of HAdV-vector vaccines and medicines should focus on preexisting antibodies in target groups rather than a "one-size-fits-all" strategy. It might be advantageous in selecting HAdV vectors for studying the prevalence of preexisting antibodies against HAdVs in different locations and people throughout the world.

Evaluation of the effectiveness and safety of sequential vaccination with inactivated SARS-CoV-2 vaccine and Ad5-nCoV booster in pediatric liver transplant recipients

Amidst the COVID-19 pandemic, uncertainty persists among caregivers regarding the vaccination of pediatric liver transplant recipients (PLTRs). This study evaluates the immunogenicity and safety of COVID-19 vaccination in this vulnerable population. A cohort of 30 PLTRs underwent sequential vaccinations with an inactivated SARS-CoV-2 vaccine followed by an Ad5-nCoV booster. We collected and analyzed blood samples pre-vaccination and four weeks post-vaccination to quantify antibody and IGRA (IFN-γ Release Assay) levels. We also documented any adverse reactions occurring within seven days post-vaccination and monitored participants for infections over six months post-vaccination, culminating in a comprehensive statistical analysis. The Ad5-nCoV booster substantially elevated IgG (T1: 18.01, 20%; T2: 66.61, 55%) and nAb (T1: 119.29, 8%; T2: 3799.75, 80%) levels, as well as T-cell responses, in comparison to the initial dose. The first dose was associated with some common adverse reactions, such as injection site pain (13.3%) and fever (16.6%), but a low rate of systemic reactions (16.0%). There was no significant difference in Omicron infection rates or RTPCR conversion times between vaccinated and unvaccinated groups. Notably, following Omicron infection, vaccinated individuals exhibited significantly higher SARS-CoV-2 IgG and nAb titers (average IgG: 231.21 vs. 62.09 S/CO, p = 0.0003; nAb: 5246.11 vs. 2592.07 IU/mL, p = 0.0002). The use of inactivated vaccines followed by an Ad5-nCoV booster in PLTRs is generally safe and elicits a robust humoral response, albeit with limited T-cell responses.

Autoimmune response after SARS-CoV-2 infection and SARS-CoV-2 vaccines

The complicated relationships between autoimmunity, COVID-19, and COVID-19 vaccinations are described, giving insight into their intricacies. Antinuclear antibodies (ANA), anti-Ro/SSA, rheumatoid factor, lupus anticoagulant, and antibodies against interferon (IFN)-I have all been consistently found in COVID-19 patients, indicating a high prevalence of autoimmune reactions following viral exposure. Furthermore, the discovery of human proteins with structural similarities to SARS-CoV-2 peptides as possible autoantigens highlights the complex interplay between the virus and the immune system in initiating autoimmunity. An updated summary of the current status of COVID-19 vaccines is presented. We present probable pathways underpinning the genesis of COVID-19 autoimmunity, such as bystander activation caused by hyperinflammatory conditions, viral persistence, and the creation of neutrophil extracellular traps. These pathways provide important insights into the development of autoimmune-related symptoms ranging from organ-specific to systemic autoimmune and inflammatory illnesses, demonstrating the wide influence of COVID-19 on the immune system.

SARS-CoV-2 vaccination willingness and humoral vaccination response in radiation oncology patients

BACKGROUND

SARS-CoV-2 infection has been and, in some parts, still is a threat to oncologic patients, making it crucial to understand perception of vaccination and immunologic responses in this vulnerable patient segment. SARS-CoV-2 vaccines in relation to malignant disease characteristics and therapies have so far not been studied consecutively in larger oncologic patient populations. This study captures SARS-CoV-2 vaccination willingness and humoral immune response in a large consecutive oncologic patient collective at the beginning of 2021.

METHODS

1142 patients were consecutively recruited over 5.5 months at a tertiary department for radiation oncology and were assessed for vaccination willingness via a standardized interview. In already vaccinated patients total SARS-CoV-2 S antibody titres against the spike protein (Anti-SARS-CoV-2 S) and were evaluated 35 days or later after the first dose of SARS-CoV-2 vaccine.

RESULTS

Vaccination willingness was high with a rate of 90 %. The most frequent reasons for rejection were: undecided/potential vaccination after therapy, distrust in the vaccine and fear of interaction with comorbidities. Factors associated with lower vaccination willingness were: worse general condition, lower age and female sex. 80 % of the participants had been previously vaccinated, 8 % reported previous infection and 16 % received vaccination during antineoplastic therapy. In 97.5 % of the vaccinated patients Anti-SARS-CoV-2 S was detected. In a univariable analysis parameters associated with non-conversion were: lower performance status, spread to the local lymphatics (N + ), hematologic disease and diffuse metastases. All patients with oligometastatic disease achieved positive Anti-SARS-CoV-2 S titres. For patients with two vaccinations several risk factors were identified, that were associated with low antibody concentrations.

CONCLUSIONS

SARS-CoV-2 vaccination willingness among oncologic patients was high in the first months after its availability, and most patients had already received one or two doses. Over 97 % of vaccinated patients had measurable anti-SARS-CoV-2 S titres. Our data supports early identification of low humoral responders after vaccination and could facilitate the design of future oncologic vaccine trials (clinicaltrials.gov Identifier: NCT04918888).

Development of NP-Based Universal Vaccine for Influenza A Viruses

The nucleoprotein (NP) is a vital target for the heterosubtypic immunity of CD8+ cytotoxic T lymphocytes (CTLs) due to its conservation among influenza virus subtypes. To further enhance the T cell immunity of NP, autophagy-inducing peptide C5 (AIP-C5) from the CFP10 protein of Mycobacterium tuberculosis was used. Mice were immunized intranasally (i.n.) with human adenoviral vectors, HAd-C5-NP(H7N9) or HAd-NP(H7N9), expressing NP of an H7N9 influenza virus with or without the AIP-C5, respectively. Both vaccines developed similar levels of NP-specific systemic and mucosal antibody titers; however, there was a significantly higher number of NP-specific CD8 T cells secreting interferon-gamma (IFN-γ) in the HAd-C5-NP(H7N9) group than in the HAd-NP(H7N9) group. The HAd-C5-NP(H7N9) vaccine provided better protection following the challenge with A/Puerto Rico/8/1934(H1N1), A/Hong Kong/1/68(H3N2), A/chukkar/MN/14951-7/1998(H5N2), A/goose/Nebraska/17097/2011(H7N9), or A/Hong Kong/1073/1999(H9N2) influenza viruses compared to the HAd-NP(H7N9) group. The autophagy transcriptomic gene analysis of the HAd-C5-NP(H7N9) group revealed the upregulation of some genes involved in the positive regulation of the autophagy process. The results support further exploring the use of NP and AIP-C5 for developing a universal influenza vaccine for pandemic preparedness.

Development of Adenovirus-Based Covid-19 Vaccine Candidate in Indonesia

Covid-19 pandemic has struck worldwide by end of 2019 and the use of various vaccine platforms was one of the main strategies to end this. To meet the needs for vaccine technology equality among many countries, we developed adenovirus-based Covid-19 vaccine candidate in Indonesia. SARS-CoV-2 Spike gene (S) was constructed into pAdEasy vector. The recombinant serotype 5 Adenovirus (AdV_S) genome was transfected into AD293 cells to produce recombinant adenovirus. Characterization using PCR confirmed the presence of spike gene. Transgene expression analysis showed the expression of S protein in AdV_S infected AD293 and A549 cells. Optimization of viral production showed the highest titer was obtained at MOI of 0.1 and 1 at 4 days. The in vivo study was performed by injecting Balb/c mice with 3.5 × 107 ifu of purified adenovirus. The result showed that S1-specific IgG was increased up to 56 days after single-dose administration of AdV_S. Interestingly, significant increase of S1 glycoprotein-specific IFN-γ ELISpot was observed in AdV_S treated Balb/c mice. In conclusion, the AdV_S vaccine candidate was successfully produced at laboratory scale, immunogenic, and did not cause severe inflammation in Balb/c mice. This study serves as initial step towards manufacturing of adenovirus-based vaccine in Indonesia.

To be remembered: B cell memory response against SARS-CoV-2 and its variants in vaccinated and unvaccinated individuals

COVID-19 disease has plagued the world economy and affected the overall well-being and life of most of the people. Natural infection as well as vaccination leads to the development of an immune response against the pathogen. This involves the production of antibodies, which can neutralize the virus during future challenges. In addition, the development of cellular immune memory with memory B and T cells provides long-lasting protection. The longevity of the immune response has been a subject of intensive research in this field. The extent of immunity conferred by different forms of vaccination or natural infections remained debatable for long. Hence, understanding the effectiveness of these responses among different groups of people can assist government organizations in making informed policy decisions. In this article, based on the publicly available data, we have reviewed the memory response generated by some of the vaccines against SARS-CoV-2 and its variants, particularly B cell memory in different groups of individuals.

Evaluation of the immunoprotective effects of porcine deltacoronavirus subunit vaccines

Porcine deltacoronavirus (PDCoV), a new porcine enteric coronavirus, has seriously endangered the pig breeding industry and caused great economic losses. However, a PDCoV vaccine is not commercially available. Therefore, new and efficient PDCoV vaccines must be developed without delay. In this study, we used the ExpiCHO eukaryotic expression system to express and purify the following 3 structural proteins of PDCoV: S, N and M. Subsequently, the level of humoral and cellular immunity induced by the S protein (immunization with the S protein alone) and a protein mixture (immunization with a mixture of S, N and M proteins) were evaluated in mice and piglets, respectively, and the performances of the 2 immunizations in a challenge protection test were assessed in piglets. The results showed that both the S protein and the protein mixture induced the production of high levels of specific IgG antibodies and neutralizing antibodies and effectively neutralized PDCoV-infected LLC-PK cells in vitro. Furthermore, compared with the S protein, the N and M proteins in the protein mixture promoted the expression of CD8+ T cells and IFN-γ, induced a stronger cellular immune response, and effectively protected 4/5 of the piglets from PDCoV infection. In conclusion, the results of this study showed that the N and M proteins play important roles in inducing an immunoprotective response. Using N and M antigens as effective antigenic components in the development of PDCoV vaccines in the future will effectively increase the immune efficacy of the vaccines.

Next-generation biological vector platforms for in vivo delivery of genome editing agents

CRISPR-based genome editing holds promise for addressing genetic disease, infectious disease, and cancer and has rapidly advanced from primary research to clinical trials in recent years. However, the lack of safe and potent in vivo delivery methods for CRISPR components has limited most ongoing clinical trials to ex vivo gene therapy. Effective CRISPR in vivo genome editing necessitates an effective vehicle ensuring target cell transduction while minimizing off-target effects, toxicity, and immune reactions. In this review, we examine promising biological-derived platforms to deliver DNA editing agents in vivo and the engineering thereof, encompassing potent viral-based vehicles, flexible protein nanocages, and mammalian-derived particles.

COVID-19 Vaccines: Where Did We Stand at the End of 2023?

Vaccine development against SARS-CoV-2 has been highly successful in slowing down the COVID-19 pandemic. A wide spectrum of approaches including vaccines based on whole viruses, protein subunits and peptides, viral vectors, and nucleic acids has been developed in parallel. For all types of COVID-19 vaccines, good safety and efficacy have been obtained in both preclinical animal studies and in clinical trials in humans. Moreover, emergency use authorization has been granted for the major types of COVID-19 vaccines. Although high safety has been demonstrated, rare cases of severe adverse events have been detected after global mass vaccinations. Emerging SARS-CoV-2 variants possessing enhanced infectivity have affected vaccine protection efficacy requiring re-design and re-engineering of novel COVID-19 vaccine candidates. Furthermore, insight is given into preparedness against emerging SARS-CoV-2 variants.

Evaluation of SARS-CoV-2 Antibody Levels in Pharmacists and Pharmacy Staff Following CoronaVac Vaccination

Objectives

The aim of this study was to determine the seropositivity rate of pharmacists and pharmacy staff after the administration of two doses of the CoronaVac-SinoVac vaccine and to assess changes in their antibody levels according to sociodemographic characteristics.

Materials and Methods

This descriptive study was conducted between June 04, 2021 and September 30, 2021 in pharmacies located in Istanbul, Türkiye. The results of self-initiated immunoglobulin (Ig) G testing of the pharmacists and pharmacy staff, conducted at diagnostic laboratories contracted by the Istanbul Chamber of Pharmacists, were obtained using an online data collection tool. IgG measurements taken from 15 days up to 120 days after the two vaccine doses were included in the study. Participants were asked whether they smoked, had any chronic diseases (hypertension, chronic obstructive pulmonary disease, asthma, diabetes, etc.), or took any medications. Subgroup analyses were performed for each method used to measure antibody levels.

Results

The study included 329 pharmacists/pharmacy staff (298 pharmacists and 31 pharmacy staff). The mean age of the participants was 49.7 ± 13.7 years, and 71.4% were female. The antibody positivity of the 329 participants was 94.9% following the two doses. The positivity rate was 95.4% in participants under 65 years of age, whereas it was 91.8% in those aged 65 years and over. There was no significant difference in the mean age between those with positive and negative antibody results (p > 0.05). Although antibody levels were lower older people, smokers, and those with chronic diseases, this difference was not statistically significant (p > 0.05).

Conclusion

Seropositivity developed following the administration of two doses of CoronaVac-Sinovac vaccines. IgG antibody levels were lower in older adults, smokers, and those with chronic diseases, although not to a statistically significant extent. Further studies are needed to better understand the reasons for the different immunological responses to COVID-19.

A quest for universal anti-SARS-CoV-2 T cell assay: systematic review, meta-analysis, and experimental validation

Measuring SARS-CoV-2-specific T cell responses is crucial to understanding an individual's immunity to COVID-19. However, high inter- and intra-assay variability make it difficult to define T cells as a correlate of protection against COVID-19. To address this, we performed systematic review and meta-analysis of 495 datasets from 94 original articles evaluating SARS-CoV-2-specific T cell responses using three assays - Activation Induced Marker (AIM), Intracellular Cytokine Staining (ICS), and Enzyme-Linked Immunospot (ELISPOT), and defined each assay's quantitative range. We validated these ranges using samples from 193 SARS-CoV-2-exposed individuals. Although IFNγ ELISPOT was the preferred assay, our experimental validation suggested that it under-represented the SARS-CoV-2-specific T cell repertoire. Our data indicate that a combination of AIM and ICS or FluoroSpot assay would better represent the frequency, polyfunctionality, and compartmentalization of the antigen-specific T cell responses. Taken together, our results contribute to defining the ranges of antigen-specific T cell assays and propose a choice of assay that can be employed to better understand the cellular immune response against viral diseases.

Investigation of COVID-19 vaccination among maintenance hemodialysis patients in Sichuan, China

AIM

To investigate the current status of COVID-19 vaccination in maintenance hemodialysis (MHD) patients and its influencing factors.

METHODS

In total, 585 patients undergoing regular hemodialysis in Sichuan Province of China from January to March 2022 were selected to complete a questionnaire survey on their knowledge, attitudes and practices regarding COVID-19 vaccination. Independent t tests and logistic multivariate analysis were used to analyze the influencing factors of COVID-19 vaccination in hemodialysis patients.

RESULTS

The survey showed that 37.44% of MHD patients had been vaccinated with the COVID-19 vaccine. Being married was associated with COVID-19 vaccination in patients with MHD (odds ratio [OR] = 1.969 95% CI 0 .870 ~ 4.453). MHD patients living in county areas have higher rates of COVID-19 vaccination (OR = 0.572 95% CI 0.301 ~ 1.087). Family /relatives/friends who are healthcare workers are associated with COVID-19 vaccination for MHD patients (OR = 1.840 95% CI 1.140 ~ 2.970). Other vaccination history within 5 years was a factor in COVID-19 vaccination for MHD patients (OR = 5.592 95% CI 2.997 ~ 10.434). Attitude (OR = 0.885 95% CI 0.808 ~ 0.905), and practice (OR = 0.756 95% CI 0.697 ~ 0.819) scores on the COVID-19 vaccination knowledge and practice questionnaire were related to the vaccination status of MHD patients.

CONCLUSIONS

MHD patients had lower rates of COVID-19 vaccination. Marital status, living environment, whether family/relatives/friends were medical workers, and the score of the COVID-19 vaccine knowledge and practice questionnaire were the factors influencing their vaccination status. Clinical attention should be given to the adverse reactions of COVID-19 vaccination in MHD patients to improve the awareness of primary medical staff on hemodialysis, and families and society should pay more attention to COVID-19 vaccination in MHD patients.

Immunogenicity and adverse events of the COVID-19 vaccines in healthy and individuals with autoimmune diseases in an Iranian population

Introduction: Recent studies have proposed various COVID-19 vaccines to control the disease and protect susceptible individuals. However, immunogenicity and safety of COVID-19 vaccines in various populations are not well identified yet. Therefore, this study aimed to elucidate the efficacy and safety of the BBIBP-CorV (Sinopharm) and ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in healthy subjects and patients with autoimmune diseases.Methods: Study population included 121 healthy subjects and 100 patients with autoimmune diseases. Immunization was performed based on the national vaccination protocols. Of the 221 volunteers, 201 subjects received Sinopharm and 20 cases were vaccinated with Oxford-AstraZeneca. During a 1-year follow-up, the immunogenicity was measured by ELISA before primary vaccination and 1 to 3 months after secondary immunization. Side effects were studied before entering the study and 1 week after the second dose.Results: Vaccination had a positive impact on the induction of immunogenic response (p < .0001). The rates of seropositive vaccine responses were 80% and 75% in subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. The neutralizing antibody values were significantly higher in subjects with autoimmune diseases than those without autoimmunity (p < .05). The rate of adverse events were 38% and 42% in subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. The rates of immunogenic responses induced with the Sinopharm and Oxford-AstraZeneca were, respectively, 76% and 81.5% in seropositive subjects, while they were 63.8% and 79.1% in seronegative subjects vaccinated with the Sinopharm and Oxford-AstraZeneca, respectively. Individuals previously infected with SARS-CoV-2 showed a significant reduction in the value of SARS-CoV-2 neutralizing antibodies compared with seronegative subjects (p < .01-.05). Seropositive individuals vaccinated with the Sinopharm had significantly higher the percentages of vaccine-related adverse events than seronegative persons (p < .05). There was no significant difference between seronegative and seropositive individuals vaccinated with the Oxford-AstraZeneca.Conclusion: Our findings revealed that the Sinopharm and Oxford-AstraZeneca vaccines are effective in the production of neutralizing antibodies in healthy subjects and patients with autoimmune disorders undergoing immunosuppressive therapies without considerable reactogenicity.

Safety and immunogenicity of different booster vaccination schemes for COVID-19 used in El Salvador

Purpose

The effectiveness of coronavirus disease 2019 (COVID-19) vaccination schemes and the combination of vaccines of various platforms for administering booster doses is still being studied since it will depend on the population's response to vaccines. We aimed to evaluate the safety, protection, and immunogenicity of the Salvadorean population's third dose booster COVID-19 vaccine and the potential benefit of homologous vs. heterologous regimens.

Materials and Methods

This is an analytical observational cohort study in a population aged 18 to 65 years that was primarily vaccinated with AstraZeneca, Sinovac, or Pfizer/BioNTech. Volunteers were recruited (n=223) and followed up for 3 months after receiving the 3rd vaccine (BNT162b2) as a booster. Adverse reactions were monitored, serum anti-spike immunoglobulin G (IgG) was assessed by chemiluminescence, and a polymerase chain reaction was carried out when subjects developed clinical signs.

Results

The cohorts finally included 199 participants, and we observed only mild adverse effects in all cohorts. A significant increase in specific IgG levels was found after the booster dose in all cohorts. The heterologous scheme with Sinovac showed the greatest increase in antibody titer, and a decrease was observed in all participants after 3 months. During the follow-up period, 30 participants showed symptomatology compatible with COVID-19, but only four were laboratory-confirmed and they showed mild clinical signs.

Conclusion

These findings indicate that the booster doses used were safe and promoted an immediate increase in immunogenicity, which decreased over time. The heterologous regimen showed stronger immunogenicity compared to the messenger RNA-based homologous scheme.

Impaired antibody response to inactivated COVID-19 vaccines in hospitalized patients with type 2 diabetes

Patients with type 2 diabetes (T2D) are at an increased risk of morbidity and mortality of coronavirus disease 2019 (COVID-19). Data on the antibody response to COVID-19 vaccines in T2D patients are less studied. This study aimed to evaluate IgG antibody response to inactivated COVID-19 vaccines in hospitalized T2D patients. Hospitalized patients with no history of COVID-19 and received two doses of inactivated COVID-19 vaccines (Sinopharm or CoronaVac) were included in this study from March to October 2021. SARS-CoV-2 specific IgG antibodies were measured 14-60 days after the second vaccine dose. A total of 209 participants, 96 with T2D and 113 non-diabetes patients, were included. The positive rate and median titer of IgG antibody against receptor-binding domain (anti-RBD) of spike (S) protein of SARS-CoV-2 in T2D group were lower than in control group (67.7% vs 83.2%, p = .009; 12.93 vs 17.42 AU/ml, p = .014) respectively. Similarly, seropositivity and median titers of IgG antibody against the nucleocapsid (N) and S proteins of SARS-CoV-2 (anti-N/S) in T2D group were lower than in control group (68.8% vs 83.2%, p = .032; 18.81 vs 29.57 AU/mL, p = .012) respectively. After adjustment for age, sex, BMI, vaccine type, days after the second vaccine dose, hypertension, kidney disease, and heart disease, T2D was identified as an independent risk factor for negative anti-RBD and anti-N/S seropositivity, odd ratio 0.42 (95% confidence interval 0.19, 0.89) and 0.42 (95% CI 0.20, 0.91), respectively. T2D is associated with impaired antibody response to inactivated COVID-19 vaccine.

Ad5-nCoV Vaccination Could Induce HLA-E Restricted CD8+ T Cell Responses Specific for Epitopes on Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein

We evaluated cellular immune responses induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in an immunized population based on HLA-E-restricted CD8+ T cell epitope identification. HLA-E-restricted SARS-CoV-2 CD8+ T cell nonamer peptides were predicted with software. An HLA-E-transfected K562 cell binding assay was used to screen for high-affinity peptides. IFN-γ enzyme-linked immunospot assays were used to identify HLA-E-restricted epitopes. An HLA-E/epitope tetramer was employed to detect the frequencies of epitope-specific CD8+ T cells. Four CD8+ T cell epitopes on the spike protein of SARS-CoV-2 restricted by both HLA-E*0101 and E*0103 were identified. HLA-E-restricted epitope-specific IFN-γ-secreting CD8+ T cell responses could be detected in individuals vaccinated with SARS-CoV-2 vaccines. Importantly, the frequencies of epitope-specific CD8+ T cells in Ad5-nCoV vaccinated individuals were higher than in individuals vaccinated with recombinant protein or inactivated vaccines. Moreover, the frequencies of epitope-specific CD8+ T cells could be maintained for at least 120 days after only one dose of Ad5-nCoV vaccine, while the frequencies of epitope-specific CD8+ T cells decreased in individuals after two doses of Ad5-nCoV vaccine. These findings may contribute to a more comprehensive evaluation of the protective effects of vaccines for SARS-CoV-2; meanwhile, they may provide information to characterize HLA-E-restricted CD8+ T cell immunity against SARS-CoV-2 infection.

Strategies for the development and approval of COVID-19 vaccines and therapeutics in the post-pandemic period

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant casualties and put immense strain on public health systems worldwide, leading to economic recession and social unrest. In response, various prevention and control strategies have been implemented globally, including vaccine and drug development and the promotion of preventive measures. Implementing these strategies has effectively curbed the transmission of the virus, reduced infection rates, and gradually restored normal social and economic activities. However, the mutations of SARS-CoV-2 have led to inevitable infections and reinfections, and the number of deaths continues to rise. Therefore, there is still a need to improve existing prevention and control strategies, mainly focusing on developing novel vaccines and drugs, expediting medical authorization processes, and keeping epidemic surveillance. These measures are crucial to combat the Coronavirus disease (COVID-19) pandemic and achieve sustained, long-term prevention, management, and disease control. Here, we summarized the characteristics of existing COVID-19 vaccines and drugs and suggested potential future directions for their development. Furthermore, we discussed the COVID-19-related policies implemented over the past years and presented some strategies for the future.

Evaluation of the humoral and mucosal immune response of a multiepitope vaccine against COVID-19 in pigs

Introduction

This study evaluated the immune response to a multiepitope recombinant chimeric protein (CHIVAX) containing B- and T-cell epitopes of the SARS-CoV-2 spike's receptor binding domain (RBD) in a translational porcine model for pre-clinical studies.

Methods

We generated a multiepitope recombinant protein engineered to include six coding conserved epitopes from the RBD domain of the SARS-CoV-2 S protein. Pigs were divided into groups and immunized with different doses of the protein, with serum samples collected over time to determine antibody responses by indirect ELISA and antibody titration. Peptide recognition was also analyzed by Western blotting. A surrogate neutralization assay with recombinant ACE2 and RBDs was performed. Intranasal doses of the immunogen were also prepared and tested on Vietnamese minipigs.

Results

When the immunogen was administered subcutaneously, it induced specific IgG antibodies in pigs, and higher doses correlated with higher antibody levels. Antibodies from immunized pigs recognized individual peptides in the multiepitope vaccine and inhibited RBD-ACE2 binding for five variants of concern (VOC). Comparative antigen delivery methods showed that both, subcutaneous and combined subcutaneous/intranasal approaches, induced specific IgG and IgA antibodies, with the subcutaneous approach having superior neutralizing activity. CHIVAX elicited systemic immunity, evidenced by specific IgG antibodies in the serum, and local mucosal immunity, indicated by IgA antibodies in saliva, nasal, and bronchoalveolar lavage secretions. Importantly, these antibodies demonstrated neutralizing activity against SARS-CoV-2 in vitro.

Discussion

The elicited antibodies recognized individual epitopes on the chimeric protein and demonstrated the capacity to block RBD-ACE2 binding of the ancestral SARS-CoV-2 strain and four VOCs. The findings provide proof of concept for using multiepitope recombinant antigens and a combined immunization protocol to induce a neutralizing immune response against SARS-CoV-2 in the pig translational model for preclinical studies.

Safety and immunogenicity of a heterologous booster with an RBD virus-like particle vaccine following two- or three-dose inactivated COVID-19 vaccine

LYB001 is an innovative recombinant SARS-CoV-2 vaccine that displays a repetitive array of the spike glycoprotein's receptor-binding domain (RBD) on a virus-like particle (VLP) vector to boost the immune system, produced using Covalink plug-and-display protein binding technology. LYB001's safety and immunogenicity were assessed in 119 participants receiving a booster with (1) 30 μg LYB001 (I-I-30 L) or CoronaVac (I-I-C), (2) 60 μg LYB001 (I-I-60 L) or CoronaVac in a ratio of 2:1 after two-dose primary series of inactivated COVID-19 vaccine, and (3) 30 μg LYB001 (I-I-I-30 L) after three-dose inactivated COVID-19 vaccine. A well-tolerated reactogenicity profile was observed for LYB001 as a heterologous booster, with adverse reactions being predominantly mild in severity and transient. LYB001 elicited a substantial increase in terms of the neutralizing antibody response against prototype SARS-CoV-2 28 days after booster, with GMT (95%CI) of 1237.8 (747.2, 2050.6), 554.3 (374.6, 820.2), 181.9 (107.6, 307.6), and 1200.2 (831.5, 1732.3) in the I-I-30 L, I-I-60 L, I-I-C, and I-I-I-30 L groups, respectively. LYB001 also elicited a cross-neutralizing antibody response against the BA.4/5 strain, dominant during the study period, with GMT of 201.1 (102.7, 393.7), 63.0 (35.1, 113.1), 29.2 (16.9, 50.3), and 115.3 (63.9, 208.1) in the I-I-30 L, I-I-60 L, I-I-C, and I-I-I-30 L groups, respectively, at 28 days after booster. Additionally, RBD-specific IFN-γ, IL-2, IL-4 secreting T cells dramatically increased at 14 days after a single LYB001 booster. Our data confirmed the favorable safety and immunogenicity profile of LYB001 and supported the continued clinical development of this promising candidate that utilizes the VLP platform to provide protection against COVID-19.

Safety of COVID-19 Vaccination in Patients With Breast Cancer: Cross-Sectional Study in China

BACKGROUND

The widespread use of vaccines against the novel coronavirus disease (COVID-19) has become one of the most effective means to establish a population immune barrier. Patients with cancer are vulnerable to COVID-19 infection, adverse events, and high mortality, and should be the focus of epidemic prevention and treatment. However, real-world data on the safety of vaccines for patients with breast cancer are still scarce.

OBJECTIVE

This study aims to compare the safety of COVID-19 vaccines between patients vaccinated before or after being diagnosed with breast cancer.

METHODS

Patients with breast cancer who sought medical advice from October 2021 to December 2021 were screened. Those who received COVID-19 vaccines were enrolled in this study to analyze the safety of the vaccines. The primary outcome was patient-reported adverse events (AEs). All events after vaccine injection were retrospectively documented from the patients.

RESULTS

A total of 15,455 patients with breast cancer from 41 hospitals in 20 provinces in China were screened, and 5766 patients who received COVID-19 vaccines were enrolled. Of those enrolled, 45.1% (n=2599) of patients received vaccines before breast cancer diagnosis, 41.3% (n=2379) were vaccinated after diagnosis, and 13.6% (n=784) did not known the accurate date of vaccination or cancer diagnosis. Among the patients vaccinated after diagnosis, 85.4% (n=2032) were vaccinated 1 year after cancer diagnosis and 95.4% (n=2270) were vaccinated during early-stage cancer. Of all 5766 vaccinated patients, 93.9% (n=5415) received an inactivated vaccine, 3.7% (n=213) received a recombinant subunit vaccine, and 2.4% (n=138) received other vaccines, including adenovirus and mRNA vaccines. In the first injection of vaccines, 24.4% (n=10, 95% CI 11.2-37.5) of patients who received an adenovirus vaccine reported AEs, compared to only 12.5% (n=677, 95% CI 11.6-13.4) of those who received an inactivated vaccine. Patients with metastatic breast cancer reported the highest incidence of AEs (n=18, 16.5%, 95% CI 9.5-23.5). Following the second injection, patients who received an inactivated vaccine (n=464, 8.7%, 95% CI 8.0-9.5) and those who received a recombinant vaccine (n=25, 8.7%, 95% CI 5.5-12.0) reported the same incidence of AEs. No significant differences in patient-reported AEs were found between the healthy population and patients with breast cancer (16.4% vs 16.9%, respectively); the most common AEs were local pain (11.1% vs 9.1%, respectively), fatigue (5.5% vs 6.3%, respectively), and muscle soreness (2.3% vs 3.6%, respectively). The type of vaccine and time window of vaccination had little impact on patient-reported AEs.

CONCLUSIONS

Compared with patients vaccinated before breast cancer diagnosis, there were no significant differences in patient-reported AEs in the patients vaccinated after diagnosis. Thus, it is safe for patients with breast cancer, especially for those in the early stage, to receive COVID-19 vaccines.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200055509; https://tinyurl.com/33zzj882.