COVID-19 Vaccines

SARS-CoV-2 vaccination reduces the risk of thrombotic complications in severe COVID-19

OBJECTIVES

The aim of this study was to evaluate the association between SARS-CoV-2 vaccination and the occurrence of thrombotic complications in patients admitted to intensive care for severe COVID-19 pneumonia.

DESIGN

Observational, descriptive, prospective, multicentre study.

SETTING

Intensive care units of five university hospitals.

PATIENTS

A total of 255 patients admitted to the intensive care unit (ICU) with SARS-CoV-2 pneumonia, confirmed by RT-PCR in throat swab or tracheal aspirate, starting the date the first vaccinated patient against SARS-CoV-2 was admitted in one of the participating ICUs, were included in the analysis.

MAIN VARIABLES OF INTEREST

Vaccination status against SARS-CoV-2 and thrombotic events.

RESULTS

18.8% of patients had received some form of vaccination. Thrombotic events occurred in 21.2% of patients. Lack of vaccination was associated with thrombotic events (OR 5.024; 95% CI: 1.104-23.123; p = 0.0037) and death (OR 5.161; 95% CI: 1.075-24.787; p = 0.04). ICU mortality was not associated with the occurrence of thrombotic complications.

CONCLUSIONS

In this series of patients, vaccination against SARS-CoV-2 reduced the risk of thrombotic events and mortality in patients with severe COVID-19 admitted to the ICU. Thrombotic complications did not alter ICU mortality.

Host-Directed Therapy in Pandemic Preparedness

This JAMA Viewpoint explores the addition of host-directed therapy using immunotherapeutic agents to pandemic preparedness programs.

Applications of liposomes and lipid nanoparticles in cancer therapy: current advances and prospects

Liposomes and lipid nanoparticles are common lipid-based drug delivery systems and play important roles in cancer treatment and vaccine manufacture. Although significant progress has been made with these lipid-based nanocarriers in recent years, efficient clinical translation of active targeted liposomal nanocarriers remains extremely challenging. In this review, we focus on targeted liposomes, stimuli-responsive strategy and combined therapy in cancer treatment. We also summarize advances of liposome and lipid nanoparticle applications in nucleic acid delivery and tumor vaccination. In addition, we discuss limitations and challenges in the clinical translation of these lipid nanomaterials and make recommendations for the future research in cancer therapy.

Heterologous mRNA/MVA delivering trimeric-RBD as effective vaccination regimen against SARS-CoV-2: COVARNA Consortium

Despite the high efficiency of current SARS-CoV-2 mRNA vaccines in reducing COVID-19 morbidity and mortality, waning immunity and the emergence of resistant variants underscore the need for novel vaccination strategies. This study explores a heterologous mRNA/Modified Vaccinia virus Ankara (MVA) prime/boost regimen employing a trimeric form of the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein compared to a homologous MVA/MVA regimen. In C57BL/6 mice, the RBD was delivered during priming via an mRNA vector encapsulated in nanoemulsions (NE) or lipid nanoparticles (LNP), followed by a booster with a replication-deficient MVA-based recombinant virus (MVA-RBD). This heterologous mRNA/MVA regimen elicited strong anti-RBD binding and neutralizing antibodies (BAbs and NAbs) against both the ancestral SARS-CoV-2 strain and different variants of concern (VoCs). Additionally, this protocol induced robust and polyfunctional RBD-specific CD4 and CD8 T cell responses, particularly in animals primed with mLNP-RBD. In K18-hACE2 transgenic mice, the LNP-RBD/MVA combination provided complete protection from morbidity and mortality following a live SARS-CoV-2 challenge compared with the partial protection observed with mNE-RBD/MVA or MVA/MVA regimens. Although the mNE-RBD/MVA regimen only protects half of the animals, it was able to induce antibodies with Fc-mediated effector functions besides NAbs. Moreover, viral replication and viral load in the respiratory tract were markedly reduced and decreased pro-inflammatory cytokine levels were observed. These results support the efficacy of heterologous mRNA/MVA vaccine combinations over homologous MVA/MVA regimen, using alternative nanocarriers that circumvent intellectual property restrictions of current mRNA vaccine formulations.

Implementation of an Immunoassay Based on the MVA-T7pol-Expression System for Rapid Identification of Immunogenic SARS-CoV-2 Antigens: A Proof-of-Concept Study

The emergence of hitherto unknown viral pathogens presents a great challenge for researchers to develop effective therapeutics and vaccines within a short time to avoid an uncontrolled global spread, as seen during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, rapid and simple methods to identify immunogenic antigens as potential therapeutical targets are urgently needed for a better pandemic preparedness. To address this problem, we chose the well-characterized Modified Vaccinia virus Ankara (MVA)-T7pol expression system to establish a workflow to identify immunogens when a new pathogen emerges, generate candidate vaccines, and test their immunogenicity in an animal model. By using this system, we detected severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) nucleoprotein (N)-, and spike (S)-specific antibodies in COVID-19 patient sera, which is in line with the current literature and our observations from previous immunogenicity studies. Furthermore, we detected antibodies directed against the SARS-CoV-2-membrane (M) and -ORF3a proteins in COVID-19 patient sera and aimed to generate recombinant MVA candidate vaccines expressing either the M or ORF3a protein. When testing our candidate vaccines in a prime-boost immunization regimen in humanized HLA-A2.1-/HLA-DR1-transgenic H-2 class I-/class II-knockout mice, we were able to demonstrate M- and ORF3a-specific cellular and humoral immune responses. Hence, the established workflow using the MVA-T7pol expression system represents a rapid and efficient tool to identify potential immunogenic antigens and provides a basis for future development of candidate vaccines.

The immune response to Covid-19 mRNA vaccination among Lymphoma patients receiving anti-CD20 treatment

The monoclonal antibody rituximab improves clinical outcome in the treatment of CD20-positive lymphomatous neoplasms, and it is an established drug for treatment of these cancers. Successful mRNA COVID-19 (SARS-CoV-2) vaccination is extremely important for lymphoma patients because they tend to be elderly with comorbidities which leaves them at increased risk of poor outcomes once infected by Coronavirus. Anti-CD20 therapies such as rituximab, deplete B-cell populations and can affect vaccine efficacy. Therefore, a knowledge of the effect of COVID-19 vaccination in this group is critical. We followed a cohort of 28 patients with CD20-positive lymphomatous malignancies treated with rituximab that started prior to their course of COVID-19 vaccination, including boosters. We assayed for vaccine "take" in the humoral (IgG and IgA) and cellular compartment. Here, we show that short-term and long-term development of IgG and IgA antibodies directed toward COVID-19 spike protein are reduced in these patients compared to healthy controls. Conversely, the robustness and breath of underlying T-cell response is equal to healthy controls. This response is not limited to specific parts of the spike protein but spans the spike region, including response to the conserved Receptor Binding Domain (RBD). Our data informs on rational vaccine design and bodes well for future vaccination strategies that require strong induction of T-cell responses in these patients.

COVID-19 Infection and Vaccination Effects on Breast Implant Illness: A Case Report

Breast implant illness (BII) is a term used to describe a range of symptoms associated with silicone breast implants. This condition suggests that silicone may trigger symptoms in individuals who are immunologically predisposed, and the spectrum of symptoms may be linked to autonomic dysregulation in these patients. We present the case of a female patient in her mid-40s with a history of autoimmune thyroiditis who had not required prior therapy. She underwent breast augmentation and subsequently developed gradual difficulties. After recovering from a COVID-19 infection, her nonspecific symptoms, consistent with BII, worsened. These symptoms included chronic fatigue, hair loss, dry skin, petechiae, low-grade fever, and frequent urination. Additionally, she developed symptoms associated with long COVID. A subsequent Pfizer-BioNTech COVID-19 vaccination further exacerbated her symptoms and overall condition. Due to the broad spectrum of nonspecific symptoms, the patient underwent numerous screenings over an 18-month period, which were inconclusive. We hypothesize that the vaccination and previous infection had a synergistic effect on her ongoing BII symptoms, contributing to the worsening of her condition. An isolated right-sided seroma with left-sided lymphadenopathy appeared to be a side effect of the vaccine. Additionally, the patient developed a newly diagnosed allergy to polyethylene glycol and other allergic manifestations, such as chronic urticaria, which are consistent with autonomic nervous system dysregulation and long COVID. These symptoms resolved within three weeks of explantation with en bloc capsulectomy. It is noteworthy that the patient was unaware of BII until an MRI revealed a suspected intracapsular implant rupture on the right side, which led to the decision to remove the implants.

Pregnancy outcomes following natural conception and assisted reproduction treatment in women who received COVID-19 vaccination prior to conception: a population-based cohort study in China

Introduction

The coronavirus disease-2019 (COVID-19) pandemic has swept across the world and continues to exert serious adverse effects on vulnerable populations, including pregnant women and neonates. The vaccines available at present were designed to prevent infection from COVID-19 strains and control viral spread. Although the incidence of pregnancy cycle outcomes are not likely to increase patients vaccinated prior to pregnancy compared with unvaccinated patients based on our knowledge of vaccination safety, there is no specific evidence to support this hypothesis. Therefore, the current study aimed to investigate the association between maternal vaccination prior to conception and pregnancy outcomes.

Methods

We retrospectively analyzed 2,614 women who received prenatal care and delivered in the Obstetrical Department of The First Affiliated Hospital of Anhui Medical University between February 2022 and November 2022. Of the 1,380 eligible pregnant women, 899 women who had received preconception vaccination were assigned to a vaccine group and 481 women who were not vaccinated were control group. Of the enrolled patients, 291 women received fertility treatment (141 vaccinated women, 150 unvaccinated women). The primary outcomes were pregnancy complications (hypothyroidism, gestational diabetes mellitus, pregnancy-induced hypertension, polyhydramnios, oligohydramnios, premature rupture of membranes and postpartum hemorrhage), obstetric outcomes (preterm birth rate, cesarean section rate) and neonatal outcomes (birth-weight, body length, low-birth-weight rate, rate of congenital defects, neonatal mortality and admission to the neonatal intensive care unit).

Results

There was no significant difference in the incidence of complications during pregnancy and delivery when compared between the vaccine group and control group in either univariate- or multivariate-models. The type of vaccine was not associated with the odds of adverse pregnancy outcome. Among the women with infertility treatment, the vaccinated group and the unvaccinated group had similar pregnancy outcomes.

Conclusion

Women who received COVID-19 vaccination prior to conception had similar maternal and neonatal outcomes as women who were unvaccinated. Our findings indicate that COVID-19 vaccinations can be safely administered prior to pregnancy in women who are planning pregnancy or assisted reproductive treatment. During new waves of COVID-19 infection, women who are planning pregnancy should be vaccinated as soon as possible to avoid subsequent infections.

A retrospective study of SARS-CoV-2 seroprevalence in dogs and cats in the Community of Madrid, Spain

To date, susceptibility to SARS-CoV-2 infection in domestic animals including cats and dogs has been described. However, it is important to carry out passive surveillance of these animals to be aware of any changes in the outcomes of the disease in these species that may occur. In this study, we have performed a retrospective study in which we analyzed sera (n = 1,640) from random animals: dogs (n = 1,381) and cats (n = 259) belonging to both homes (n = 1,533) and animal protection centers (n = 107) in the Community of Madrid, Spain. Neutralizing antibodies were evaluated between November 2021 and May 2022 using a surrogate ELISA kit to determine the seroprevalence. Based on the results obtained, a few animals (both cats and dogs) presented neutralizing antibodies to SARS-CoV-2 (2.3%), all of them from private owners. However, the seroprevalence in cats (4.6%) resulted to be almost twice as much as in dogs (1.9%) which reinforces that cats' susceptibility to the infection seems higher than in the case of dogs, maybe due to the lower ACE2 expression of the dogs in the respiratory tract. These findings also confirm that the probability of infection is considerably higher in domestic animals in close contact with infected owners, compared to animals living in animal shelters whose contact with humans is markedly lower.

Tracking trends in COVID-19 vaccines based on 47 different vaccines: A bibliometric review

The COVID-19 epidemic in December 2019 had a significant negative impact on people's health and economies all across the world. The most effective preventive measure against COVID-19 is vaccination. Therefore, the development and production of COVID-19 vaccines is booming worldwide. This study aimed to analyze the current state of that research and its development tendency by bibliometrics. We conducted a thorough search of the Web of Science Core Collection. VOSviewer1.6.18 was used to perform the bibliometric analysis of these papers. A total of 6,325 papers were finally included. The USA maintained a top position worldwide. Shimabukuro Tom T and Harvard University were the most prolific author and institution. The Vaccines was the most published journal. The research hotspots of COVID-19 vaccines can be classified into vaccine hesitancy, vaccine safety and effectiveness, vaccine immunogenicity, and adverse reactions to vaccines. Studies on various vaccination types have also concentrated on efficacy against continuously developing virus strains, immunogenicity, side effects, and safety.

Social Representations of Hesitant Brazilians about Vaccination against COVID-19

BACKGROUND

The control of the COVID-19 pandemic has been a great challenge. Understanding the thoughts and beliefs underlying vaccine hesitancy can help in the formulation of public policies. The present study aimed to analyze the social representations of hesitant Brazilians about vaccination against COVID-19.

METHODS

Qualitative research guided by the Theory of Social Representations, carried out through an online survey among Brazilian adults living in Brazil. The data were analyzed using the IRaMuTeQ software.

RESULTS

Of the 173,178 respondents, 10,928 were hesitant and declared reasons for vaccination hesitation. The analysis generated three classes: mistrust of the vaccine and underestimation of the severity of the pandemic; (dis)information and distrust of political involvement; and fear of adverse reactions to COVID-19 vaccines.

CONCLUSIONS

Social knowledge, presented by the representations apprehended in this study, demonstrates difficulty in discerning the reliability of information and a social imagination full of doubts and uncertainties. Understanding the internal dynamics of these groups, with their representations of the world, is important to propose policies and actions that echo and cause changes in the understanding of the role of immunization. It is essential to shed light on the sociological imagination so that gaps filled with false information can be dismantled and confronted with scientific knowledge accessible to the population.

A mathematic equation derived from host-pathogen interactions elucidates the significance of integrating modern medicine with traditional Chinese medicine to treat infectious diseases

The prognosis of infectious diseases is determined by host-pathogen interactions. Control of pathogens has been the central dogma of treating infectious diseases in modern medicine, but the pathogen-directed medicine is facing significant challenges, including a lack of effective antimicrobials for newly emerging pathogens, pathogen drug resistance, and drug side effects. Here, a mathematic equation (termed equation of host-pathogen interactions, HPI-Equation) is developed to dissect the key variables of host-pathogen interactions. It shows that control of pathogens does not necessarily lead to host recovery. Instead, a combination of promoting a host's power of self-healing and balancing immune responses provides the best benefit for host. Moreover, the HPI-Equation elucidates the scientific basis of traditional Chinese medicine (TCM), a host-based medicine that treats infectious diseases by promoting self-healing power and balancing immune responses. The importance of self-healing power elucidated in the HPI-Equation is confirmed by recent studies that the tolerance mechanism, which is discovered in plants and animals and conceptually similar to self-healing power, improves host survival without directly attacking pathogens. In summary, the HPI-Equation describes host-pathogen interactions with mathematical logic and precision; it translates the ancient wisdoms of TCM into apprehensible modern sciences and opens a new venue for integrating TCM and modern medicine for a future medicine.

High-Density Lipoprotein function is modulated by the SARS-CoV-2 spike protein in a lipid-type dependent manner

There is a close relationship between the SARS-CoV-2 virus and lipoproteins, in particular high-density lipoprotein (HDL). The severity of the coronavirus disease 2019 (COVID-19) is inversely correlated with HDL plasma levels. It is known that the SARS-CoV-2 spike (S) protein binds the HDL particle, probably depleting it of lipids and altering HDL function. Based on neutron reflectometry (NR) and the ability of HDL to efflux cholesterol from macrophages, we confirm these observations and further identify the preference of the S protein for specific lipids and the consequent effects on HDL function on lipid exchange ability. Moreover, the effect of the S protein on HDL function differs depending on the individuals lipid serum profile. Contrasting trends were observed for individuals presenting low triglycerides/high cholesterol serum levels (LTHC) compared to high triglycerides/high cholesterol (HTHC) or low triglycerides/low cholesterol serum levels (LTLC). Collectively, these results suggest that the S protein interacts with the HDL particle and, depending on the lipid profile of the infected individual, it impairs its function during COVID-19 infection, causing an imbalance in lipid metabolism.

Epidemiology and Clinical Presentation of COVID-19 in Older Adults

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains asymptomatic in 33% to 90% of older adults depending on their immune status from prior infection, vaccination, and circulating strain. Older adults symptomatic with SARS-CoV-2 often both present atypically, such as with a blunted fever response, and develop more severe disease. Early and late reports showed that older adults have increased severity of coronavirus disease 2019 (COVID-19) with higher case fatality rates and higher intensive care needs compared with younger adults. Infection and vaccine-induced antibody response and long-term effects of COVID-19 also differ in older adults.

Leishmania tarentolae: a vaccine platform to target dendritic cells and a surrogate pathogen for next generation vaccine research in leishmaniases and viral infections

Parasites of the genus Leishmania are unusual unicellular microorganisms in that they are characterized by the capability to subvert in their favor the immune response of mammalian phagocytes, including dendritic cells. Thus, in overt leishmaniasis, dendritic cells and macrophages are converted into a niche for Leishmania spp. in which the parasite, rather than being inactivated and disassembled, survives and replicates. In addition, Leishmania parasites hitchhike onto phagocytic cells, exploiting them as a mode of transport to lymphoid tissues where other phagocytic cells are potentially amenable to parasite colonization. This propensity of Leishmania spp. to target dendritic cells has led some researchers to consider the possibility that the non-pathogenic, reptile-associated Leishmania tarentolae could be exploited as a vaccine platform and vehicle for the production of antigens from different viruses and for the delivery of the antigens to dendritic cells and lymph nodes. In addition, as L. tarentolae can also be regarded as a surrogate of pathogenic Leishmania parasites, this parasite of reptiles could possibly be developed into a vaccine against human and canine leishmaniases, exploiting its immunological cross-reactivity with other Leishmania species, or, after its engineering, for the expression of antigens from pathogenic species. In this article we review published studies on the use of L. tarentolae as a vaccine platform and vehicle, mainly in the areas of leishmaniases and viral infections. In addition, a short summary of available knowledge on the biology of L. tarentolae is presented, together with information on the use of this microorganism as a micro-factory to produce antigens suitable for the serodiagnosis of viral and parasitic infections.

Prevalence and Risk Factors of Adverse Effects and Allergic Reactions after COVID-19 Vaccines in a Mexican Population: An Analytical Cross-Sectional Study

Vaccinations have helped to control the COVID-19 pandemic; however, few studies focus on the adverse effects and allergic reactions of these vaccines and fewer have a scope in the Latin American population. The objective of this study was to assess the associations between vaccinations, sex, age, allergic reactions, and adverse effects. This was an analytical cross-sectional study conducted between 1 July and 1 October 2022. The sample consisted of 443 surveyed participants, with a total of 1272 COVID-19 vaccine doses. Seven vaccines (Pfizer BioNTech, Oxford-AstraZeneca, CanSino, Moderna, Johnson and Johnson, Sinovac, and Sputnik V) were evaluated. A total of 12.6% of those surveyed had at least one allergic reaction posterior to vaccination, and females had a greater chance of developing one (p < 0.001, OR 3.1). The most common allergic reaction was chest pain, and Pfizer-BioNTech and Oxford-AstraZeneca were associated with the onset of allergic reactions (p < 0.005). A total of 54.6% of those surveyed developed adverse effects, the most common of which were myalgia, fever, cephalea, asthenia or adynamia, and arthralgia; moreover, older age was associated with the onset of adverse effects (p < 0.5). This study concludes that the BNT162b2 (Pfizer BioNTech) and ChAdOX1 nCOV-19 (Oxford-AstraZeneca) vaccines are strongly associated with the onset of allergic reactions, with ORs of 1.6 (CI 95%, 1.18 to 2.3) and 1.87 (CI 95%, 1.35 to 2.6), respectively. In addition, females have a greater chance of developing allergic reactions associated with COVID-19 vaccinations, and there was a relation found between older age and a greater prevalence of comorbidities, adverse effects after vaccination, and COVID-19 infection after vaccination.

Efficacy and Safety of COVID-19 Vaccine in Patients on Renal Replacement Therapy

Patients with CKD on RRT are at high risk for severe disease and mortality in COVID-19 disease. We decided to conduct an observational prospective study to evaluate antibody response after vaccination for COVID-19 in a cohort of 210 adult patients on RRT (148 on HD; 20 on PD; and 42 kidney transplant recipients). Blood samples were taken before and 4 weeks after vaccination. Antibody levels were evaluated with CLIA immunoassay testing for IgG anti-trimeric spike protein of SARS-CoV-2. A positive antibody titer was present in 89.9% of HD patients, 90% of PD patients, and 52.4% of kidney transplant recipients. Non-responders were more frequent among patients on immunosuppressive therapy. Mycophenolate use in kidney transplant patients was associated with lower antibody response. The median antibody titer was 626 (228–1480) BAU/mL; higher in younger patients and those previously exposed to the virus and lower in HD patients with neoplasms and/or on immunosuppressive therapy. Only two patients developed COVID-19 in the observation period: they both had mild disease and antibody titers lower than 1000 BAU/mL. Our data show a valid response to COVID-19 mRNA vaccination in HD and PD patients and a reduced response in kidney transplant recipients. Mycophenolate was the most relevant factor associated with low response.