Vaccine Vector Research Articles

Protective MVA-ST Vaccination Robustly Activates T Cells and Antibodies in an Aged-Hamster Model for COVID-19.

Aging is associated with a decline in immune system functionality. So-called immunosenescence may impair the successful vaccination of elderly people. Thus, improved vaccination strategies also suitable for an aged immune system are required. Modified Vaccinia virus Ankara (MVA) is a highly attenuated and replication-deficient vaccinia virus that has been established as a multipurpose viral vector for vaccine development against various infections. We characterized a recombinant MVA expressing a prefusion-stabilized version of SARS-CoV-2 S protein (MVA-ST) in an aged-hamster model for COVID-19. Intramuscular MVA-ST immunization resulted in protection from disease and severe lung pathology. Importantly, this protection was correlated with a potent activation of SARS-CoV-2 specific T-cells and neutralizing antibodies. Our results suggest that MVA vector vaccines merit further evaluation in preclinical models to contribute to future clinical development as candidate vaccines in elderly people to overcome the limitations of age-dependent immunosenescence.

A potential dual protection vaccine: Recombinant feline herpesvirus-1 expressing feline parvovirus VP2 antigen

Recently, herpesvirus viral vectors that stimulate strong humoral and cellular immunity have been demonstrated to be the most promising platforms for the development of multivalent vaccines, because they contain various nonessential genes and exhibit long-life latency characteristics. Previously, we showed that the feline herpesvirus-1 (FHV-1) mutant WH2020-ΔTK/gI/gE, which was safe for felines and provided efficacious protection against FHV-1 challenge, can be used as a vaccine vector. Moreover, previous studies have shown that the major neutralizing epitope VP2 protein of feline parvovirus (FPV) can elicit high levels of neutralizing antibodies. Therefore, to develop a bivalent vaccine against FPV and FHV-1, we first generated a novel recombinant virus by CRISPR/Cas9-mediated homologous recombination, WH2020-ΔTK/gI/gE-VP2, which expresses the VP2 protein of FPV. The growth characteristics of WH2020-ΔTK/gI/gE-VP2 were similar to those of WH2020-ΔTK/gI/gE, and WH2020-ΔTK/gI/gE-VP2 was stable for at least 30 generations in CRFK cells. As expected, we found that the felines immunized with WH2020-ΔTK/gI/gE-VP2 produced FPV-neutralizing antibody titers (27.5) above the positive cutoff (26) on day 14 after single inoculation. More importantly, recombinant WH2020-ΔTK/gI/gE-VP2 exhibited severely impaired pathogenicity in inoculated and cohabiting cats. The kittens immunized with WH2020-ΔTK/gI/gE and WH2020-ΔTK/gI/gE-VP2 produced similar levels of FHV-specific antibodies and IFN-β. Furthermore, felines immunized with WH2020-ΔTK/gI/gE-VP2 were protected against challenge with FPV and FHV-1. These data showed that WH2020-ΔTK/gI/gE-VP2 appears to be a potentially safe, effective, and economical bivalent vaccine against FPV and FHV-1 and that WH2020-ΔTK/gI/gE can be used as a viral vector to develop feline multivalent vaccines.

Advancements, challenges, and future perspectives in developing feline herpesvirus 1 as a vaccine vector.

As the most prevalent companion animal, cats are threatened by numerous infectious diseases and carry zoonotic pathogens such as Toxoplasma gondii and Bartonella henselae, which are the primary causes of human toxoplasmosis and cat-scratch disease. Vaccines play a crucial role in preventing and controlling the spread of diseases in both humans and animals. Currently, there are only three core vaccines available to prevent feline panleukopenia, feline herpesvirus, and feline calicivirus infections, with few vaccines available for other significant feline infectious and zoonotic diseases. Feline herpesvirus, a major component of the core vaccine, offers several advantages and a stable genetic manipulation platform, making it an ideal model for vaccine vector development to prevent and control feline infectious diseases. This paper reviews the technologies involved in the research and development of the feline herpesvirus vaccine vector, including homologous recombination, CRISPR/Cas9, and bacterial artificial chromosomes. It also examines the design and effectiveness of expressing antigens of other pathogens using the feline herpesvirus as a vaccine vector. Additionally, the paper analyzes existing technical bottlenecks and challenges, providing an outlook on its application prospects. The aim of this review is to provide a scientific basis for the research and development of feline herpesvirus as a vaccine vector and to offer new ideas for the prevention and control of significant feline infectious and zoonotic diseases.

A single-dose MCMV-based vaccine elicits long-lasting immune protection in mice against distinct SARS-CoV-2 variants.

Current vaccines against COVID-19 elicit immune responses that are overall strong but wane rapidly. As a consequence, the necessary booster shots have contributed to vaccine fatigue. Hence, vaccines that would provide lasting protection against COVID-19 are needed, but are still unavailable. Cytomegaloviruses (CMVs) elicit lasting and uniquely strong immune responses. Used as vaccine vectors, they may be attractive tools that obviate the need for boosters. Therefore, we tested the murine CMV (MCMV) as a vaccine vector against COVID-19 in relevant preclinical models of immunization and challenge. We have previously developed a recombinant MCMV vaccine vector expressing the spike protein of the ancestral SARS-CoV-2 (MCMVS). In this study, we show that the MCMVS elicits a robust and lasting protection in young and aged mice. Notably, spike-specific humoral and cellular immunity was not only maintained but also even increased over a period of at least 6 months. During that time, antibody avidity continuously increased and expanded in breadth, resulting in neutralization of genetically distant variants, like Omicron BA.1. A single dose of MCMVS conferred rapid virus clearance upon challenge. Moreover, MCMVS vaccination controlled two variants of concern (VOCs), the Beta (B.1.135) and the Omicron (BA.1) variants. Thus, CMV vectors provide unique advantages over other vaccine technologies, eliciting broadly reactive and long-lasting immune responses against COVID-19.

Global, regional, and national burden of dengue, 1990–2021: Findings from the global burden of disease study 2021

BackgroundDengue is an acute viral infectious disease caused by the dengue virus and transmitted through mosquitoes. Although numerous studies have examined the global burden of dengue, comprehensive and systematic global analyses remain limited. This study uses data from the Global Burden of Disease (GBD) Study 2021 to systematically analyze the global epidemiological trends and disease burden of dengue from 1990 to 2021. MethodsThis study utilized data from the GBD Study 2021 Study to analyze trends in the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of dengue across 204 countries and territories, stratified by age, sex, and Socio-demographic Index (SDI) levels. In addition, a Bayesian age-period-cohort model was employed to predict the future burden of dengue. The average annual percent change (AAPC) was used to describe the overall trend in rates or counts of indicators between 1990 and 2021. ResultsIn 2021, the global ASIR of dengue was 752.04 per 100,000 population (95 % UI: 196.33–1363.35), and ASMR was 0.38 per 100,000 population (95 % UI: 0.23–0.51). From 1990 to 2021, both the ASIR (AAPC = 7.89, 95 % CI: 7.89–8.91) and ASMR (AAPC = 0.01, 95 % CI: 0.00–0.01) showed an increasing trend. Adolescents under 14 years had the highest ASIR, age-standardized prevalence rate (ASPR), and age-standardized disability-adjusted life years (DALYs) for dengue. By 2035, the projected ASIR of dengue is 862.23 per 100,000 population (95 % CI: 627.84–1096.62 per 100,000 population), the ASPR is 51.60 per 100,000 population (95 % CI: 37.70–65.50 per 100,000 population), and the ASMR is 0.43 per 100,000 population (95 % CI: 0.29–0.56 per 100,000 population). The ASIR, ASPR, ASMR, and age-standardized DALYs for dengue are expected to continue rising in the next 10 years. ConclusionThe global burden of dengue is projected to continue rising in the coming years, underscoring the urgent need for comprehensive control measures, including enhanced vector control, public education, vaccination, and drug development. These findings provide crucial scientific evidence for the formulation of effective public health strategies and interventions aimed at reducing the global threat posed by dengue.

MVA-based vaccine candidates expressing SARS-CoV-2 prefusion-stabilized spike proteins of the Wuhan, Beta or Omicron BA.1 variants protect transgenic K18-hACE2 mice against Omicron infection and elicit robust and broad specific humoral and cellular immune responses.

Despite the decrease in mortality and morbidity due to SARS-CoV-2 infection, the incidence of infections due to Omicron subvariants of SARS-CoV-2 remains high. The mutations acquired by these subvariants, mainly concentrated in the receptor-binding domain (RBD), have caused a shift in infectivity and transmissibility, leading to a loss of effectiveness of the first authorized COVID-19 vaccines, among other reasons, by neutralizing antibody evasion. Hence, the generation of new vaccine candidates adapted to Omicron subvariants is of special interest in an effort to overcome this immune evasion. Here, an optimized COVID-19 vaccine candidate, termed MVA-S(3P_BA.1), was developed using a modified vaccinia virus Ankara (MVA) vector expressing a full-length prefusion-stabilized SARS-CoV-2 spike (S) protein from the Omicron BA.1 variant. The immunogenicity and efficacy induced by MVA-S(3P_BA.1) were evaluated in mice in a head-to-head comparison with the previously generated vaccine candidates MVA-S(3P) and MVA-S(3Pbeta), which express prefusion-stabilized S proteins from Wuhan strain and Beta variant, respectively, and with a bivalent vaccine candidate composed of a combination of MVA-S(3P) and MVA-S(3P_BA.1). The results showed that all four vaccine candidates elicited, after a single intramuscular dose, protection of transgenic K18-hACE2 mice challenged with SARS-CoV-2 Omicron BA.1, reducing viral loads, histopathological lesions, and levels of proinflammatory cytokines in the lungs. They also elicited anti-S IgG and neutralizing antibodies against various Omicron subvariants, with MVA-S(3P_BA.1) and the bivalent vaccine candidate inducing higher titers. Additionally, an intranasal immunization in C57BL/6 mice with all four vaccine candidates induced systemic and mucosal S-specific CD4+ and CD8+ T-cell and humoral immune responses, and the bivalent vaccine candidate induced broader immune responses, eliciting antibodies against the ancestral Wuhan strain and different Omicron subvariants. These results highlight the use of MVA as a potent and adaptable vaccine vector against new emerging SARS-CoV-2 variants, as well as the promising feature of combining multivalent MVA vaccine candidates.

COVID-19 vaccine-associated vasculitis: A systematic review.

Post-COVID-19 vaccine-associated vasculitis stands as one of the most serious side effects attributed to COVID-19 vaccines. This complication encompasses diverse manifestations which vary in presentation and severity. Moreover, it can impact patients across all age groups, with a notably elevated incidence in the elderly. This systematic review seeks to review and evaluate the spectrum of vasculitis manifestations linked to COVID-19 vaccination. A systematic review of the literature was done by searching through PubMed, Google Scholar, and Scopus up to October 2022. Articles including data about sex, age at diagnosis, vasculitis clinical manifestations, type of vaccination, most commonly used investigations, comorbid medical conditions, treatments, and clinical outcomes were included in the final analysis. Furthermore, vasculitis flare-ups post-vaccination were considered part of this review. A total number of 117 studies describing 158 patients developing vasculitis following COVID-19 vaccination were included in the final analysis. Among the patients who developed vasculitis, the most administered type of vaccination was the mRNA vaccine subtype (n = 103), followed by the viral vector vaccines (n = 42) and inactivated viral vaccines (n = 10). On the other hand, about 38% of vasculitis-related symptoms occurred after the administration of the first dose of the vaccine and 37% occurred after taking the second dose. The skin (60.7%) and the kidneys (27.8%) were the most affected organs and complete remission was achieved in 111 patients (70%), while partial remission occurred in 11% of the patient population. COVID-19 vaccine-induced vasculitis is a rare occurrence associated with COVID-19 vaccines. It generally presents a favorable prognosis and outcomes for the vast majority of patients, ultimately leading to full remission within days. This review emphasizes the notion that the advantages of COVID-19 vaccines outweigh the potential risks, particularly for individuals with compromised immune systems.

Management of HIT/anti-PF4 disorders

Heparin-induced thrombocytopenia (HIT) was widely known as a disease characterized by development of thrombosis with thrombocytopenia after heparin exposure. In addition, vaccine-induced immune thrombotic thrombocytopenia (VITT) has been described as a fatal disease involving simultaneous bleeding and thrombosis after COVID-19 adenovirus vector vaccination. These were caused by HIT antibodies and anti-PF4 antibodies, respectively, but both were autoantibodies that recognized PF4, and were found to have the same pathology with different severities. In recent years, many pathologies in which anti-PF4 antibodies are produced have been reported, and a new concept of anti-PF4 disorder has been proposed. Anti-PF4 disorders are often difficult to identify due to their diverse range of causes, and the prognosis varies greatly depending on whether anti-PF4 antibodies can be measured and early treatment performed after observation of thrombocytopenia of unknown cause or thrombosis at an unusual site. To avoid overlooking anti-PF4 disorders, clinicians should become familiar with the classification of these disorders and accurately select the necessary tests.

An Overview of Future Development Methods of Infectious Bronchitis Vaccines

Vaccines are major disease-controlling tools in human and animal practices. Vaccination controlled or even eradicated a long list of diseases worldwide. Classic viral vaccines are usually composed of live or inactivated whole viruses and have been produced for many years. However, they are unsuccessful, especially in persistent infections, fast-evolving viruses, complex and compound antigens, and emerging agents. Novel vaccine development technologies such as DNA, protein, or viral vector vaccines have revolutionized vaccine development and opened a new horizon for study and research in vaccine research and production vision. Newly-developed vaccines, or even most traditional ones, are based on new technologies, especially in human diseases where cost and complications in production can be ignored. However, in animal health, especially for commercial poultry production, the cost of development, simplicity, and mass application of large-scale production cannot be overlooked. In recent years, the significance of producing novel vaccines has been highlighted in parallel with technological advancement, especially with emerging novel variants of infectious bronchitis viruses—serious poultry pathogens for years. In this review, we will introduce some studies on novel vaccine development techniques and investigate the results of those vaccines in the protection of chickens and their clinical outcomes.

Universal Vaccine Development Against COVID-19 and Influenza

Universal vaccines appeared as a favorable solution for the rapid mutation of viruses that cause pandemics. Sufficient immune protection, safe and efficient production methods, and low-cost funding are ideal properties for universal vaccines. Targeting conserved regions, use of adjuvants, cell-mediated immunity approaches, virus-like particles, and multimeric presentation of viral antigens are strategies to enhance vaccine Immunogenicity. Different types of vaccines have been put into clinical trials, such as messenger RNA vaccines, on-replicating viral vector vaccines, and recombinant protein-based vaccines, which are proven to suit the needs of universal vaccine investigation. Moreover, this article introduces the universal vaccine development of SARS-CoV-2 and influenza variants, their vaccine candidates, research results, and the challenges faced. Universal vaccines are the trend of future viral protection, with more and more new technologies entering the field, a universal vaccine is within reach.

Public's perspective on COVID-19 adenovirus vector vaccines after thrombosis with thrombocytopenia syndrome (TTS) reports and associated regulatory actions – A cross-sectional study in six EU member states

ObjectiveIn 2021, thrombosis with thrombocytopenia syndrome (TTS) was confirmed by the European Medicines Agency (EMA) as a rare side effect of the COVID-19 adenovirus vector vaccines Vaxzevria® and Jcovden®. This study aimed to describe the public’s knowledge of TTS and how it affected the willingness to be vaccinated with COVID-19 vaccines and other vaccines in six European countries. MethodsFrom June to October of 2022, a multi-country cross-sectional online survey was conducted in Denmark, Greece, Latvia, Netherlands, Portugal, and Slovenia. The minimum target of participants to be recruited was based on the size of the country’s population. The results were analysed descriptively. ResultsIn total, 3794 respondents were included in the analysis; across the six countries, 33.3 %–68.3 % reported being familiar with signs and symptoms of TTS, although 3.1–61.4 % of those were able to identify the symptoms correctly. The reported changes in willingness to be vaccinated against COVID-19 and with other vaccines varied per country. The largest reported change in the willingness to be vaccinated with Vaxzevria® and Jcovden® was observed in Denmark (61.2 %), while the willingness to be vaccinated with other COVID-19 vaccines changed most in Slovenia (30.4 %). The smallest decrease in willingness towards future vaccination against COVID-19 was reported in the Netherlands (20.9 %) contrasting with the largest decrease observed in Latvia (69.1 %). ConclusionKnowledge about TTS seemed to have influenced the public’s opinion in Europe resulting in less willingness to be vaccinated with Vaxzevria® and Jcovden®. Willingness for vaccination against COVID-19 with other vaccines and widespread use of vaccines to prevent other diseases also differed and seemed to be determined by the approaches taken by national health authorities when reacting to and communicating about COVID-19 vaccination risks. Further investigation of optimal risk communication strategies is warranted.

Filling two needs with one deed: a combinatory mucosal vaccine against influenza A virus and respiratory syncytial virus.

Influenza A Virus (IAV) and Respiratory Syncytial Virus (RSV) are both responsible for millions of severe respiratory tract infections every year worldwide. Effective vaccines able to prevent transmission and severe disease, are important measures to reduce the burden for the global health system. Despite the strong systemic immune responses induced upon current parental immunizations, this vaccination strategy fails to promote a robust mucosal immune response. Here, we investigated the immunogenicity and efficacy of a mucosal adenoviral vector vaccine to tackle both pathogens simultaneously at their entry site. For this purpose, BALB/c mice were immunized intranasally with adenoviral vectors (Ad) encoding the influenza-derived proteins, hemagglutinin (HA) and nucleoprotein (NP), in combination with an Ad encoding for the RSV fusion (F) protein. The mucosal combinatory vaccine induced neutralizing antibodies as well as local IgA responses against both viruses. Moreover, the vaccine elicited pulmonary CD8+ and CD4+ tissue resident memory T cells (TRM) against the immunodominant epitopes of RSV-F and IAV-NP. Furthermore, the addition of Ad-TGFβ or Ad-CCL17 as mucosal adjuvant enhanced the formation of functional CD8+ TRM responses against the conserved IAV-NP. Consequently, the combinatory vaccine not only provided protection against subsequent infections with RSV, but also against heterosubtypic challenges with pH1N1 or H3N2 strains. In conclusion, we present here a potent combinatory vaccine for mucosal applications, which provides protection against two of the most relevant respiratory viruses.

Single ChAdOx1 nCoV-19 dose elicits stronger immune response in previously infected individuals than in SARS-CoV2 naive persons.

Current vaccines against COVID-19 effectively reduce morbidity and mortality and are vitally important for controlling the pandemic. Between December 2020 and February 2021, adenoviral vector vaccines such as ChAdOx1 (AstraZeneca-Oxford) were put in use. Recent reports demonstrate robust serological responses to a single dose of messenger RNA vaccines in individuals previously infected with SARS-CoV-2. We aimed to study the association between previous COVID-19 infection and antibody levels after a single dose of ChAdOx1 nCoV-19. This cross-sectional study was conducted on 657 individuals who were either convalescent or SARS-CoV-2 naive and had received one dose of ChAdOx1 (AstraZeneca). A questionnaire was used to collect data on age, sex, and self-reported history of COVID-19 infection. We then compared the average levels of immunoglobulin G (IgG) between the previously infected and COVID-19-naive participants. We compared the antibody responses of individuals with confirmed prior COVID-19 infection with those of individuals without prior evidence of infection. The mean antibody levels in those who reported no history of COVID-19 infection were substantially lower than in those who were previously infected, in both males and females. Sex-related differences were observed when we compared antibody levels between men and women. In males, anti-S IgG antibody levels were higher in those who had been previously infected (156.1 vs. 87.69 AU/mL, p = .009), compared with the same pattern was observed in females (113.5 vs. 90.69 AU/mL, p = .005). Previous COVID-19 infection is associated with higher levels of SARS-CoV-2 antibodies following ChAdOx1 (AstraZeneca) vaccination. Our finding supports the notion that a single dose of ChAdOx1 nCoV-19 administered post-SARS-CoV-2 infection serves as an effective immune booster. This provides a possible rationale for a single-dose vaccine regimen for previously infected individuals.

Recurring SARS-CoV-2 variants: an update on post-pandemic, co-infections and immune response.

The post-pandemic era following the global spread of the SARS-CoV-2 virus has brought about persistent concerns regarding recurring coinfections. While significant strides in genome mapping, diagnostics, and vaccine development have controlled the pandemic and reduced fatalities, ongoing virus mutations necessitate a deeper exploration of the interplay between SARS-CoV-2 mutations and the host's immune response. Various vaccines, including RNA-based ones like Pfizer and Moderna, viral vector vaccines like Johnson & Johnson and AstraZeneca, and protein subunit vaccines like Novavax, have played critical roles in mitigating the impact of COVID-19. Understanding their strengths and limitations is crucial for tailoring future vaccines to specific variants and individual needs. The intricate relationship between SARS-CoV-2 mutations and the immune response remains a focus of intense research, providing insights into personalized treatment strategies and long-term effects like long-COVID. This article offers an overview of the post-pandemic landscape, highlighting emerging variants, summarizing vaccine platforms, and delving into immunological responses and the phenomenon of long-COVID. By presenting clinical findings, it aims to contribute to the ongoing understanding of COVID-19's progression in the aftermath of the pandemic.

Expression of recombinant Florida clade 2 hemagglutinin in baculovirus expression system: A step for subunit vaccine development against H3N8 equine influenza virus.

Equine influenza (EI) is a transmissible viral respiratory sickness of the Equidae family. Two viruses, H7N7 and H3N8 caused EI; however, H7N7 has not been detected for decades. H3N8 has circulated and bifurcated into Eurasian and American lineages. The latter subsequently diversified into Kentucky, South America, and Florida sub-lineages. Florida clade 1 (FC1) and Florida clade 2 (FC2) strains are the only circulating EI viruses (EIVs) in the meantime. Immunization is considered the major means for the prevention and control of EI infection. Using disparate technologies and platforms, several vaccines have been developed and commercialized. According to the recommendations of the World Organization for Animal Health (WOAH), all commercial vaccines shall comprise representatives of both FC1 and FC2 strains. Unfortunately, most of the commercially available vaccines were not updated to incorporate a representative of FC2 strains. The purpose of this research was to develop a new EI vaccine candidate that incorporates the hemagglutinin (HA) antigen from the currently circulating FC2. In this study, we report the expression of the full-length recombinant HA gene of FC2 in the baculovirus expression system. The HA recombinant protein has been proven to maintain its biological characteristics by hemadsorption (HAD) and hemagglutination tests. Moreover, using a reference-specific serum, the specificity of the HA has been confirmed through the implementation of immunoperoxidase and western immunoblotting assays. In conclusion, we report the expression of specific biologically active recombinant HA of FC2, which would act as a foundation for the generation of an updated EI subunit or virus vector vaccine candidates.

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.

Risk of Bell's Palsy after COVID-19 vaccination

At the close of 2019, a global health crisis known as COVID-19, or coronavirus (2019-nCoV), broke out. Vaccination is used as a means of prevention. The COVID-19 vaccines may be categorized into four groups: viral vector, entire virus, subunit protein, and nucleic vaccines. Upon evaluating the advantages of vaccinations, it becomes evident that there are adverse side effects that may develop. Bell's palsy is regarded as a significant adverse reaction after immunization. This observational essay aims to consolidate knowledge about the SARS-CoV-2 infection and its association with the risk of Bell's palsy after COVID-19 vaccination.

Research Progress in Respiratory Syncytial Virus Vaccines

In addition to being a substantial source of morbidity and mortality in older persons, respiratory syncytial virus (RSV) is a major contributor to lower respiratory tract infections in newborns and young children. Worldwide, there has been a lot of research done to provide safe and effective vaccinations against this common infection because there isn't an approved RSV vaccine. A succinct summary of current developments in RSV vaccine research is given in this abstract. Many vaccinations have reached the clinical testing stage and shown promising benefits. Live attenuated vaccines, nanoparticle vaccines, and viral vector vaccines are the three primary categories of current vaccination techniques. Additionally, the production of specific RSV antibodies such as MEDI8897 and polyclonal immunoglobulin RI-002 is being evaluated as an important research antibodies for avoiding RSV infection. The continuous dedication to RSV vaccine development gives optimism for the future prevention of RSV-related disorders across all age groups, despite the fact that challenges still exist, particularly ERD (Enhanced respiratory disease).

Study of immunogenicity of parathyroid hormone-encoded AAV vector vaccine in a mouse model

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Immunogenicity and durability against Omicron BA.1, BA.2 and BA.4/5 variants at 3–4 months after a heterologous COVID-19 booster vaccine in healthy adults with a two-doses CoronaVac vaccination

BackgroundSeveral countries have authorized a booster vaccine campaign to combat the spread of COVID-19. Data on persistence of booster vaccine‐induced immunity against new Omicron subvariants are still limited. Therefore, our study aimed to determine the serological immune response of COVID-19 booster after CoronaVac-priming. MethodsA total of 187 CoronaVac-primed participants were enrolled and received an inactivated (BBIBP), viral vector (AZD1222) or mRNA vaccine (full-/half-dose BNT162B2, full-/half-dose mRNA-1273) as a booster dose. The persistence of humoral immunity both binding and neutralizing antibodies against wild-type and Omicron was determined on day 90–120 after booster. ResultsA waning of total RBD immunoglobulin (Ig) levels, anti-RBD IgG, and neutralizing antibodies against Omicron BA.1, BA.2, and BA.4/5 variants was observed 90–120 days after booster vaccination. Participants who received mRNA-1273 had the highest persistence of the immunogenicity response, followed by BNT162b2, AZD1222, and BBIBP-CorV. The responses between full and half doses of mRNA-1273 were comparable. The percentage reduction of binding antibody ranged from 50 % to 75 % among all booster vaccine. ConclusionsThe antibody response substantially waned after 90–120 days post-booster dose. The heterologous mRNA and the viral vector booster demonstrated higher detectable rate of humoral immune responses against the Omicron variant compared to the inactivated BBIBP booster. Nevertheless, an additional fourth dose is recommended to maintain immune response against infection.