[History and principles of vaccination]

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome following vaccination: analysis of the VAERS database and systematic review

Objectives

This study aimed to analyze the Vaccine Adverse Event Reporting System (VAERS) database and systematically review the literature to provide a comprehensive analysis of reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) secondary to vaccination.

Methods

The authors analyzed the VAERS database and conducted a systematic review following PRISMA guidelines. The inclusion criteria for VAERS data were a score of ≥3 on the RCVS2 score and/or radiographic findings consistent with the diagnosis of RCVS or PRES. The systematic review was registered with PROSPERO.

Results

Our combined data set included 29 cases (9 RCVS and 20 PRES). Most cases were women (72.4%) with a mean age of 50.7 years (SD 19.4 years). Most cases were associated with COVID-19 mRNA vaccines (58.6% Moderna, 20.7% Pfizer). Hypertension (37.9%), hyperlipidemia (13.7%), chronic kidney disease (CKD) (10.3%), and end-stage renal disease (6.8%) were common comorbidities. Furthermore, 20.6% (6/29) of cases were on immunosuppression therapy for various reasons. The mean time to symptom onset was 10.49 days after vaccination (SD 18.60), and the mean duration of hospitalization was 7.42 days (SD 5.94). The symptoms reported the most frequently were headache (41.3%), elevated blood pressure (31.0%), and emesis (17.2%). Typical radiographic findings included T2/FLAIR hyperintensities affecting the parieto-occipital lobes, indicative of vasogenic and/or cytotoxic edema.

Conclusions

This study provides a comprehensive analysis of postvaccine RCVS and PRES. Both disease states were seen most often in those with pre-existing risk factors such as female sex, age over 50, hypertension, renal disease, and immunosuppression. Vaccines and their associated immune response may cause endothelial dysfunction leading to cerebral vasospasm and loss of cerebral autoregulation. However, further research is required to understand the underlying pathophysiological mechanisms. Despite the associations found, the absolute risk of these syndromes remains extremely low compared to the immense benefits of vaccination.

Humoral immune response after SARS-CoV-2 vaccination in cladribine-treated multiple sclerosis patients

Multiple sclerosis immunomodulatory treatments such as cladribine, which affects both B- and T-lymphocytes, can potentially alter the humoral response to SARS-CoV-2 vaccination. This monocenter retrospective study reports on anti-SARS-CoV-2 IgG antibody response in cladribine treated MS patients and we compare the response in patients vaccinated before and after an 18-week interval after last cladribine dose. Of the 34 patients (5 patients ≤ 18 weeks and 29 patients > 18 weeks after last cladribine dose) that were included, 32 reached seropositivity (94 %). All patients vaccinated < 18 weeks after last cladribine dose reached seropositivity. This study confirms findings of earlier reports that cladribine-treated MS patients show an adequate humoral response after SARS-CoV-2 vaccination, even when vaccinated early (≤18 weeks) after last cladribine dose.

Advances, opportunities and challenges in developing therapeutic cancer vaccines

Therapeutic cancer vaccines have shown promising efficacy in helping immunotherapy for cancer patients, but the systematic characterization of the clinical application and the method for improving efficacy is lacking. Here, we mainly summarize the classification of therapeutic cancer vaccines, including protein vaccines, nucleic acid vaccines, cellular vaccines and anti-idiotypic antibody vaccines, and subdivide the above vaccines according to different types and delivery forms. Additionally, we outline the clinical efficacy and safety of vaccines, as well as the combination strategies of therapeutic cancer vaccines with other therapies. This review will provide a detailed overview and rationale for the future clinical application and development of therapeutic cancer vaccines.

Lipid-Based Nanotechnology: Liposome

Over the past several decades, liposomes have been extensively developed and used for various clinical applications such as in pharmaceutical, cosmetic, and dietetic fields, due to its versatility, biocompatibility, and biodegradability, as well as the ability to enhance the therapeutic index of free drugs. However, some challenges remain unsolved, including liposome premature leakage, manufacturing irreproducibility, and limited translation success. This article reviews various aspects of liposomes, including its advantages, major compositions, and common preparation techniques, and discusses present U.S. FDA-approved, clinical, and preclinical liposomal nanotherapeutics for treating and preventing a variety of human diseases. In addition, we summarize the significance of and challenges in liposome-enabled nanotherapeutic development and hope it provides the fundamental knowledge and concepts about liposomes and their applications and contributions in contemporary pharmaceutical advancement.

Vaccines development in India: advances, regulation, and challenges

One of the most significant medical advancements in human history is the development of vaccines. Progress in vaccine development has always been greatly influenced by scientific human innovation. The main objective of vaccine development would be to acquire sufficient evidence of vaccine effectiveness, immunogenicity, safety, and/or quality to support requests for marketing approval. Vaccines are biological products that enhance the body's defenses against infectious diseases. From the first smallpox vaccine to the latest notable coronavirus disease 2019 nasal vaccine, India has come a long way. The development of numerous vaccines, driven by scientific innovation and advancement, combined with researcher's knowledge, has helped to reduce the global burden of disease and mortality rates. The Drugs and Cosmetics Rules of 1945 and the New Drugs and Clinical Trials Rules of 2019 specify the requirements and guidelines for CMC (chemistry, manufacturing, and controls) for all manufactured and imported vaccines, including those against coronavirus infections. This article provides an overview of the regulation pertaining to the development process, registration, and approval procedures for vaccines, particularly in India, along with their brief history.

Identification of Immunodominant Proteins of the Leishmania (Viannia) naiffi SubProteome as Pan-Specific Vaccine Targets against Leishmaniasis

Leishmaniasis is a wide-spectrum disease caused by parasites from Leishmania genus. A well-modulated immune response that is established after the long-lasting clinical cure of leishmaniasis can represent a standard requirement for a vaccine. Previous studies demonstrated that Leishmania (Viannia) naiffi causes benign disease and its antigens induce well-modulated immune responses in vitro. In this work we aimed to identify the immunodominant proteins present in the soluble extract of L. naiffi (sLnAg) as candidates for composing a pan-specific anti-leishmaniasis vaccine. After immunoblotting using cured patients of cutaneous leishmaniasis sera and proteomics approaches, we identified a group of antigenic proteins from the sLnAg. In silico analyses allowed us to select mildly similar proteins to the host; in addition, we evaluated the binding potential and degree of promiscuity of the protein epitopes to HLA molecules and to B-cell receptors. We selected 24 immunodominant proteins from a sub-proteome with 328 proteins. Homology analysis allowed the identification of 13 proteins with the most orthologues among seven Leishmania species. This work demonstrated the potential of these proteins as promising vaccine targets capable of inducing humoral and cellular pan-specific immune responses in humans, which may in the future contribute to the control of leishmaniasis.

Determinants of the decision to be vaccinated against COVID-19 as exemplified by employees of a long-term health care centre

INTRODUCTION

Health care professionals cover the front line in the battle against infectious diseases. Vaccination of healthcare workers represents a vital element of the strategy for enhancing epidemic safety and improving the quality of health care, inter alia, by limiting microorganism transmission, and reducing patient morbidity and mortality.

METHOD

The study group consisted of all employees of the long-term health care centre in Lublin, Poland. Participants were requested to complete a questionnaire prepared for the purpose of the study, along with a mandatory COVID-19 vaccination interview questionnaire.

RESULTS

The vaccination coverage rate for the group of medical workers was 77.3% and of non-medical 86%. The most frequently indicated sources of information on vaccination were the mass media. Males more often than females used the press as a source of information on vaccination. Scientific articles were the most common source of information for both people with higher education and medical professionals. The most common motive for vaccination for females is concern for the health of one's family, and for HCWs and people with at least secondary education-concern for the health of patients.

CONCLUSION

At least one assessed factor influences the decision to be vaccinated. The mass media are of the greatest importance in obtaining information about vaccination.

Bibliometric Analysis of Global Scientific Production on COVID-19 and Vaccines

This bibliometric analysis aims to analyze the global scientific production of COVID-19 and vaccines. First, a search for scientific articles was performed using the advanced query in the Web of Science™ database, more precisely in its core collection, on 18 February 2023. Data from 7754 articles were analyzed using the Bibliometrix R package and the Biblioshiny application. The evaluated articles were published mainly in 2022 (60%). The scientific journals that published the most about COVID-19 and vaccines were "Vaccines", "Vaccine" and "Human Vaccines & Immunotherapeutics". The University of Oxford was the most productive institution, with the authors of the articles mainly originating from the United States, China and the United Kingdom. The United States, despite having carried out the most significant number of collaborations, published mainly with local researchers. The 15 most cited articles and the KeyWords Plus™ evidenced the focus of the published articles on the safety and efficacy of vaccines against COVID-19, as well as on the evaluation of vaccine acceptance, more specifically on vaccine hesitancy. Research funding came primarily from US government agencies.

Regulation of innate and adaptive immunity using herbal medicine: benefits for the COVID-19 vaccination

Vaccination is a major achievement that has become an effective prevention strategy against infectious diseases and active control of emerging pathogens worldwide. In response to the coronavirus disease 2019 (COVID-19) pandemic, several diverse vaccines against severe acute respiratory syndrome coronavirus 2 have been developed and deployed for use in a large number of individuals, and have been reported to protect against symptomatic COVID-19 cases and deaths. However, the application of vaccines has a series of limitations, including protective failure for variants of concern, unavailability of individuals due to immune deficiency, and the disappearance of immune protection for increasing infections in vaccinated individuals. These aspects raise the question of how to modulate the immune system that contributes to the COVID-19 vaccine protective effects. Herbal medicines are widely used for their immune regulatory abilities in clinics. More attractively, herbal medicines have been well accepted for their positive role in the COVID-19 prevention and suppression through regulation of the immune system. This review presents a brief overview of the strategy of COVID-19 vaccination and the response of the immune system to vaccines, the regulatory effects and mechanisms of herbal medicine in immune-related macrophages, natural killer cells, dendritic cells, and lymphocytes T and B cells, and how they help vaccines work. Later in the article, the potential role and application of herbal medicines in the most recent COVID-19 vaccination are discussed. This article provides new insights into herbal medicines as promising alternative supplements that may benefit from COVID-19 vaccination.

Graphical abstract

http://links.lww.com/AHM/A31.

Anti-NMDA receptor encephalitis and vaccination: A disproportionality analysis

Anti–N-methyl-D-aspartate receptor (NMDAR) encephalitis is an auto-immune neurological disorder characterized by the presence in the cerebrospinal fluid (CSF) of antibodies against the GluN1 subunit of NMDA receptors in the brain. The etiology of the disease remains largely unknown. In this study, we aimed to investigate the possible existence of pharmacovigilance signals relating to a link between vaccination and the occurrence of anti-NMDAR encephalitis. We performed a case/non-case study using data from the World Health Organization pharmacovigilance database (VigiBase) up to 31 December 2021. All individual case study reports (ICSRs) linked to a vaccine and coded with the MedDRA Lower Level Term (LLT) “anti-NMDA receptor encephalitis” were analysed. We calculated the Reporting Odds Ratio (ROR) and 95% Confidence Interval (CI) for each type of vaccine. A total of 29,758,737 ICSRs were registered in VigiBase, of which 70 were coded under the selected LLT, and 29/70 (41.4%) involved a vaccine. Of these cases, 53.8% involved children aged younger than 15 years. The median time to onset of anti-NMDAR encephalitis after vaccination was 4 days (range 0–730). The highest RORs were observed for the diphtheria/polio/tetanus/pertussis vaccine [54.72 (95% CI 26.2–114.3)], yellow fever vaccine [50.02 (95% CI 15.7–159)] and human papillomavirus vaccine [32.89 (15.8–68.7)]. All cases were coded as serious; 13 patients did not recover, or were left with permanent sequelae. Nine patients recovered without sequelae or are on the path to recovery, and one patient died. In summary, pharmacovigilance signals were observed for anti-NMDAR encephalitis and vaccination. Clinicians need to be aware of this potential risk, and encourage to report any case of anti-NMDAR encephalitis occurring after vaccination.

Immunoprophylaxis using polypeptide chimera vaccines plus adjuvant system promote Th1 response controlling the spleen parasitism in hamster model of visceral leishmaniasis

In recent years, several advances have been observed in vaccinology especially for neglected tropical diseases (NTDs). One of the tools employed is epitope prediction by immunoinformatic approaches that reduce the time and cost to develop a vaccine. In this scenario, immunoinformatics is being more often used to develop vaccines for NTDs, in particular visceral leishmaniasis (VL) which is proven not to have an effective vaccine yet. Based on that, in a previous study, two predicted T-cell multi-epitope chimera vaccines were experimentally validated in BALB/c mice to evaluate the immunogenicity, central and effector memory and protection against VL. Considering the results obtained in the mouse model, we assessed the immune response of these chimeras inMesocricetus auratushamster, which displays, experimentally, similar pathological status to human and dog VL disease. Our findings indicate that both chimeras lead to a dominant Th1 response profile, inducing a strong cellular response by increasing the production of IFN-γ and TNF-α cytokines associated with a decrease in IL-10. Also, the chimeras reduced the spleen parasite load and the weight a correlation between protector immunological mechanisms and consistent reduction of the parasitic load was observed. Our results demonstrate that both chimeras were immunogenic and corroborate with findings in the mouse model. Therefore, we reinforce the use of the hamster as a pre-clinical model in vaccination trials for canine and human VL and the importance of immunoinformatic to identify epitopes to design vaccines for this important neglected disease.

Recent advances in the study of NADC34-like porcine reproductive and respiratory syndrome virus in China

Since porcine reproductive and respiratory syndrome virus (PRRSV) was first described in China in 1996, several genetically distinct strains of PRRSV have emerged with varying pathogenicity and severity, thereby making the prevention and control of PRRS more difficult in China and worldwide. Between 2017 and 2021, the detection rate of NADC34-like strain in China increased. To date, NADC34-like strains have spread to 10 Chinese provinces and have thus developed different degrees of pathogenicity and mortality. In this review, we summarize the history of NADC34-like strains in China and clarify the prevalence, genomic characteristics, restriction fragment length polymorphisms, recombination, pathogenicity, and vaccine status of this strain in China. In so doing, this study aims to provide a basis for the further development of prevention and control measures targeting the NADC34-like strain.

Immunosenescence and Altered Vaccine Efficiency in Older Subjects: A Myth Difficult to Change

Organismal ageing is associated with many physiological changes, including differences in the immune system of most animals. These differences are often considered to be a key cause of age-associated diseases as well as decreased vaccine responses in humans. The most often cited vaccine failure is seasonal influenza, but, while it is usually the case that the efficiency of this vaccine is lower in older than younger adults, this is not always true, and the reasons for the differential responses are manifold. Undoubtedly, changes in the innate and adaptive immune response with ageing are associated with failure to respond to the influenza vaccine, but the cause is unclear. Moreover, recent advances in vaccine formulations and adjuvants, as well as in our understanding of immune changes with ageing, have contributed to the development of vaccines, such as those against herpes zoster and SARS-CoV-2, that can protect against serious disease in older adults just as well as in younger people. In the present article, we discuss the reasons why it is a myth that vaccines inevitably protect less well in older individuals, and that vaccines represent one of the most powerful means to protect the health and ensure the quality of life of older adults.

Vaccination against tuberculosis, polio and hepatitis B at birth in Podor health district, Northern Senegal: cross-sectional study of vaccination coverage and its associated factors

BACKGROUND

In Senegal, studies focusing specifically on vaccination coverage with the Bacille de Calmette et Guérin (BCG) vaccine, the birth dose of oral polio vaccine (OPV zero dose) and the birth dose of hepatitis B (HepB-BD) vaccine are insufficient. This study aimed to highlight vaccination coverages with birth doses and factors associated with timely vaccination in Podor health district.

METHODS

A cross-sectional study was carried out from June 19 to 22, 2020. The study population consisted of children aged 12 to 23 months of which 832 were included. A stratified two-stage cluster survey was carried out. The sources of data were home-based records (HBR), health facility registries (HFR) and parental recalls. Timely vaccination refers to any vaccination that has taken place within 24 h after birth. Descriptive analyzes, the chi-square test and logistic regression were performed.

RESULTS

The crude vaccination coverages with BCG, OPV zero dose and HepB-BD were 95.2%, 88.3% and 88.1%, respectively. Vaccination coverages within 24 h after birth were estimated at 13.9%, 30% and 42.1%, respectively. The factors associated with timely HepB-BD are delivery in a health facility (AOR = 1.55; 95% CI = 1.02-2.40), access to television (AOR = 1.63; 95% CI = 1.16-2.29), weighing (AOR = 3.92; 95% CI = 1.97-8.53) and hospitalization of the newborn immediately after birth (AOR = 0.42; 95% CI = 0.28-0.62).

CONCLUSION

Timely administration of birth doses is a challenge in the Podor health district. The solutions would be improving geographic access to health facilities, involving community health workers, raising awareness and integrating health services.

[Vaccinations]

Vaccination is considered one of the most important achievements of modern medicine and has saved millions of lives. As a result, the age-old fear of severe or fatal infectious diseases has largely been forgotten in society; however, the pandemic triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shows how quickly this fear can return. Also, many people have reservations about medical measures, especially if they are directed against vague dangers. Paradoxically, the success of vaccinations jeopardizes the acceptance. To counteract this development, this article provides information on basic vaccination principles, legal frameworks and components of vaccines. It explains the most important categories, goals, core elements of vaccination programs and the most important recommendations of the Standing Committee on Vaccination at the Robert Koch Institute (STIKO). It explains the current state of knowledge with respect to required resources, assessment of vaccine reactions, complication management and possible vaccine damage.

Virtual Reality: Is It Helping Children Cope with Fear and Pain During Vaccination?

Background

Virtual reality (VR) is an innovative distraction technology in health care, but little is known about this topic in Saudi Arabia. The aim of this study was to assess the effectiveness of using VR to reduce pain and fear among children during vaccination.

Methods

It is a cross-sectional study design. A total of 104 children (ages 4–6 years) receiving routine vaccinations in a single primary health care in Eastern Region, Saudi Arabia, participated in the study and grouped to a VR technology intervention group or vaccination as usual without VR distraction. The primary outcome is the difference in the child’s self-rated fear and pain scores between those who have been vaccinated with or without VR distraction, measured by the two validated international facial expressions scales Wong–Baker FACES Pain Scale and Children’s Fear Scale.

Results

In the two-month study period, 53 children were vaccinated using the VR technology and 50 children were vaccinated without VR. Bivariate analysis showed a significantly lower pain score among the VR group (\documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$\overline {\bf{\it{x}}} $$ \end{document}=1.36, SD 2.06) compared with the group without VR (\documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$\overline {\bf{\it{x}}} $$ \end{document}=6.90, SD 3.47) (P-value < 0.001). Similarly, fear score was lower in the VR group (\documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$\overline {\bf{\it{x}}} $$ \end{document}=0.64, SD 0.92) compared with the group without VR (\documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$\overline {\bf{\it{x}}} $$ \end{document}=2.88, SD1.55) (P < 0.001). In multivariable regression models adjusted for age and gender, children vaccinated using the VR technology had significantly lower pain and fear scores compared with those who were vaccinated as usual without VR distraction.

Conclusion

VR technology showed a positive impact on reducing pain and fear among children aged 4–6 years during vaccination. Policymakers are encouraged to expand the use of this distraction tool in primary health centers to improve the vaccination experience among children.

Mutations of SARS-CoV-2 spike protein: Implications on immune evasion and vaccine-induced immunity

Responsible for more than 4.9 million deaths so far, COVID-19, caused by SARS-CoV-2, is instigating devastating effects on the global health care system whose impacts could be longer for the years to come. Acquiring a comprehensive knowledge of host-virus interaction is critical for designing effective vaccines and/or drugs. Understanding the evolution of the virus and the impact of genetic variability on host immune evasion and vaccine efficacy is helpful to design novel strategies to minimize the effects of the emerging variants of concern (VOC). Most vaccines under development and/or in current use target the spike protein owning to its unique function of host receptor binding, relatively conserved nature, potent immunogenicity in inducing neutralizing antibodies, and being a good target of T cell responses. However, emerging SARS-CoV-2 strains are exhibiting variability on the spike protein which could affect the efficacy of vaccines and antibody-based therapies in addition to enhancing viral immune evasion mechanisms. Currently, the degree to which mutations on the spike protein affect immunity and vaccination, and the ability of the current vaccines to confer protection against the emerging variants attracts much attention. This review discusses the implications of SARS-CoV-2 spike protein mutations on immune evasion and vaccine-induced immunity and forward directions which could contribute to future studies focusing on designing effective vaccines and/or immunotherapies to consider viral evolution. Combining vaccines derived from different regions of the spike protein that boost both the humoral and cellular wings of adaptive immunity could be the best options to cope with the emerging VOC.

Perception and attitude of the public on vaccine practices and pharmacists as immunizers in Jordan

Objective

To assess general perception and attitude of the public on vaccines current practices and pharmacists as immunizers in Jordan

Methods

In this study, computer-assisted personal interviews technique was utilized using a quantitative approach of a structured questionnaire. The survey instrument was completed with random telephonic interviews covering different geographic areas in the country of Jordan with a total sample size of 366.

Key findings

Majority of respondents had a positive perception of vaccines in general. Regarding the respondents’ perception of current vaccination status, the majority felt it is good as is or requires some enhancements. Furthermore, 53% believe pharmacists should administer vaccines. Majority strongly agree (76%) that pharmacists should be trained and certified to do so. However, 57% strongly disagree that current pharmacies in Jordan have the facilities allowing them to administer vaccines. Finally, a significant increase of 26% in public willingness to have a pharmacist immunizer after certification was observed compared to without being certified (52%).

Conclusions

Respondents support the role of vaccination as a preventative tool. However, to their opinion, contrary to the high effectiveness in paediatric vaccination in Jordan, current adult vaccination systems need to be revised and improved to increase its adult coverage. Additionally, respondents highly support the idea of allowing pharmacists to become immunizers under certain conditions regarding proper training, accredited certification and licensed administration facilities.

Replication of Small Ruminant Lentiviruses in Aluminum Hydroxide-Induced Granulomas in Sheep: a Potential New Factor for Viral Dissemination

Aluminum (Al)-based salts are widely used adjuvants in ruminants and other species to strengthen the immune response elicited against vaccine antigen(s). However, they can lead to the formation of long-lasting granulomas composed of abundant activated macrophages. Small ruminant lentiviruses (SRLV) are widely distributed macrophage-tropic retroviruses that cause persistent infections in sheep and goats. Infected monocytes/macrophages and dendritic cells establish an inflammatory microenvironment that eventually leads to clinical manifestations. The aim of this work was to study the effect of Al-induced granulomas in the replication and pathogenesis of SRLV. Eleven adult, naturally SRLV-infected sheep showing clinical arthritis were distributed in vaccine (n = 6), adjuvant-only (n = 3), and control (n = 2) groups and inoculated with commercial Al-based vaccines, Al hydroxide adjuvant alone, or phosphate-buffered saline, respectively. In vitro studies demonstrated viral replication in Al-induced granulomas in 5 out of 10 sheep. Immunohistochemistry (IHC) evinced granular, intracytoplasmic SRLV presence in macrophages within granulomas. Viral sequences obtained from granulomas, blood monocytes, and other tissues were highly similar in most animals, suggesting virus circulation among body compartments. However, notable differences between isolated strains in granulomas and other tissues in specific animals were also noted. Interestingly, the B2 subtype was the most commonly found SRLV genotype, reaching a wider body distribution than previously described. Recombination events between genotypes B2 and A3 along the gag region were identified in two sheep. Our results indicate that Al-hydroxide-derived granulomas may represent an ideal compartment for SRLV replication, perhaps altering natural SRLV infection by providing a new, suitable target tissue.IMPORTANCE Granulomas are inflammation-derived structures elicited by foreign bodies or certain infections. Aluminum adjuvants included in vaccines induce granulomas in many species. In sheep, these are persistent and consist of activated macrophages. Small ruminant lentiviruses (SRLV), which are macrophage-tropic lentiviruses, cause a chronic wasting disease affecting animal welfare and production. Here, we studied the occurrence of SRLV in postvaccination granulomas retrieved from naturally infected ewes after vaccination or inoculation with aluminum only. SRLV infection was confirmed in granulomas by identification of viral proteins, genomic fragments, and enzymatic activity. The infecting SRLV strain, previously found exclusively in carpal joints, reached the central nervous system, suggesting that occurrence of SRLV in postvaccination granulomas may broaden tissue tropism. SRLV recombination was detected in inoculated animals, a rare event in sheep lentiviruses. Potentially, virus-host interactions within granulomas may modify viral pathogenesis and lead to more widespread infection.

A review of vaccine effects on women in light of the COVID-19 pandemic

The pandemic situation triggered by the spread of COVID-19 has caused great harm worldwide. More than six million people have been infected, and more than 360,000 of them have died. This is the worst catastrophe suffered by mankind in recent history. In the face of this severe disaster, people all over the world are frightened of the prospect of facing an outbreak or an annual recurrence. However, the development of a vaccine will help control the impact of COVID-19. Women in particular have been more seriously affected by the pandemic. Since the pressure and physical load they suffer are often greater than what men endure, women are more threatened by COVID-19. Though women have a poorer quality of life and work and face worse economic conditions, they also tend to have better physiological immunity than men, which can ease the effect of COVID-19. The early development of a vaccine against COVID-19 is an important issue that must take into consideration women's better immune response to the virus along with the technique of hormone regulation. Relevant research has been conducted on female-specific vaccines in the past, and women's issues were considered during those clinical trials to ensure that complications and antibody responses were positive and effective in women. National policies should also propose good strategies for women to be vaccinated. This could improve consciousness, give women a better vaccination experience, enhance their willingness to vaccinate, and protect them from COVID-19 infection.