Staphylococcus aureus—A Known Opponent against Host Defense Mechanisms and Vaccine Development—Do We Still Have a Chance to Win?

The main purpose of this review is to present justification for the urgent need to implement specific prophylaxis of invasive Staphylococcus aureus infections. We emphasize the difficulties in achieving this goal due to numerous S. aureus virulence factors important for the process of infection and the remarkable ability of these bacteria to avoid host defense mechanisms. We precede these considerations with a brief overview of the global necessitiy to intensify the use of vaccines against other pathogens as well, particularly in light of an impasse in antibiotic therapy. Finally, we point out global trends in research into modern technologies used in the field of molecular microbiology to develop new vaccines. We focus on the vaccines designed to fight the infections caused by S. aureus, which are often resistant to the majority of available therapeutic options.

Two years of SARS-CoV-2 infection (2019–2021): structural biology, vaccination, and current global situation

The deadly SARS-CoV-2 virus has infected more than 259,502,031 confirmed cases with 5,183,003 deaths in 223 countries during the last 22 months (Dec 2019–Nov 2021), whereas approximately 7,702,859,718, vaccine doses have been administered (WHO: https://covid19.who.int/) as of the 24th of Nov 2021. Recent announcements of test trial completion of several new vaccines resulted in the launching of immunization for the common person around the globe highlighting a ray of hope to cope with this infection. Meanwhile, genetic variations in SARS-CoV-2 and third layer of infection spread in numerous countries emerged as a stronger prototype than the parental. New and parental SARS-CoV-2 strains appeared as a risk factor for other pre-existing diseases like cancer, diabetes, neurological disorders, kidney, liver, heart, and eye injury. This situation requires more attention and re-structuring of the currently developed vaccines and/or drugs against SARS-CoV-2 infection. Although a decline in COVID-19 infection has been reported globally, an increase in COVID-19 cases in the subcontinent and east Mediterranean area could be alarming. In this review, we have summarized the current information about the SARS-CoV-2 biology, its interaction and possible infection pathways within the host, epidemiology, risk factors, economic collapse, and possible vaccine and drug development.

Willingness to pay for a hypothetical malaria vaccine in Brazil: a cross-sectional study and the implications

Aim: Malaria is an infection caused by protozoa of genus Plasmodium, considered the one associated with increasingly large outbreaks. Methods: A cross-sectional study was conducted with residents in the northern region of Brazil on the willingness to pay (WTP) for a hypothetical vaccine against malaria (effective protection of 80%). Results: Of 616 people interviewed, most interviewees were female (61%) and were employed (97%). The median individual maximum WTP for a hypothetical malaria vaccine was US$11.90 (BRL 50). Conclusion: The northern region of Brazil is one of the largest markets for a malaria vaccine due to its epidemiological relevance. Consequently, economic studies will be important to assist in the assessment of the potential price and value of new vaccines.

Combination Vaccines

Combination vaccines have been around since 1945 (trivalent influenza vaccine) and they combine either different serotypes of one microorganism (e.g., influenza or pneumococcal vaccines) or different microorganisms (e.g., DTP combinations). Potential chemical and physical interactions, unpredictable immunological interactions, and in one instance: increased AE, increasing likelihood of production failures, and reduced flexibility of a vaccination program are challenges for developing combination vaccines. With an increasing number of new vaccines for protecting the very young, DTaP- and DTwP-based combinations have become the cornerstone of pediatric vaccination programs around the globe since the mid-1990s. Live vaccine combinations include MR, MMR, and MMRV combinations as well as (trivalent) OPV. Combination vaccines for travelers include HAV-HBV combination and HAV-Ty vaccines. Dozens of diverse combination vaccine products are licensed today around the globe, some of them only in single countries to cover specific local needs. Combination vaccines have been shown to result in increased acceptance, completion and compliance with vaccination programs; in addition, they offer simplified logistics, reduce administration errors, reduce the number of medical visits and cost for the individual as well as for society, among other benefits.

Multiple Sclerosis, Viruses, and New Vaccines

Multiple sclerosis (MS) is the most common inflammatory neurological disease in young adults, with an estimated prevalence of approximately 2 [...]

Current situation of vaccine injury compensation program and a future perspective in light of COVID-19 and emerging viral diseases

Background: Vaccines have had a great impact on disease prevention and reducing mortality. Very rarely, vaccines also can result in serious adverse effects. In consideration of this fact, vaccine injury compensation programs have been implemented in many countries to compensate a vaccinee for associated adverse effects. The existing vaccine injury compensation system addresses routine immunization schemes. However, there are rising concerns about the compensation for adverse effects caused by new vaccines such as those developed for coronavirus disease 2019 (COVID-19). This review focuses on vaccine injury compensation programs and highlights the necessity to include all upcoming new vaccines for COVID-19 and other emerging viral diseases in the compensation schemes. Methods: Published articles relating to vaccine compensation injury programs, vaccines, injuries, disabilities, illnesses, and deaths resulting from vaccination were searched in data bases. Through a careful review of the abstracts, 25 relevant articles were selected for analysis. Results: We identified 27 countries on four continents with vaccine injury compensation schemes: 17 countries in Europe, 7 countries in Asia, the United States, a Canadian Province and New Zealand. No programs were identified in Africa and in South America. Program design, funding, and eligibility for compensation vary vastly between countries. We identified 17 countries operating well-established vaccine injury compensation programs. However, minimal information is available on numerous other countries. Conclusion: We conclude that the vaccine injury compensation programs are available in limited number of countries across four continents - mostly in Europe. Lack of standard approach and scope of injury prevention and compensation programs across the countries exists. Some important limitations include limited scientific material, which hindered our research. Therefore, additional data concerning payout for each type of injury and the number of claimants related to a specific vaccine injury worldwide could provide a more comprehensive analysis.

The Importance of RNA-Based Vaccines in the Fight against COVID-19: An Overview

In recent years, vaccine development using ribonucleic acid (RNA) has become the most promising and studied approach to produce safe and effective new vaccines, not only for prophylaxis but also as a treatment. The use of messenger RNA (mRNA) as an immunogenic has several advantages to vaccine development compared to other platforms, such as lower coast, the absence of cell cultures, and the possibility to combine different targets. During the COVID-19 pandemic, the use of mRNA as a vaccine became more relevant; two out of the four most widely applied vaccines against COVID-19 in the world are based on this platform. However, even though it presents advantages for vaccine application, mRNA technology faces several pivotal challenges to improve mRNA stability, delivery, and the potential to generate the related protein needed to induce a humoral- and T-cell-mediated immune response. The application of mRNA to vaccine development emerged as a powerful tool to fight against cancer and non-infectious and infectious diseases, for example, and represents a relevant research field for future decades. Based on these advantages, this review emphasizes mRNA and self-amplifying RNA (saRNA) for vaccine development, mainly to fight against COVID-19, together with the challenges related to this approach.

Knowledge, Attitude, and Practice of Physicians Regarding Vaccinations in Yerevan, Armenia: A Case Study of HPV

This paper highlights the low levels of vaccine coverage and high levels of reported vaccination hesitancy in Yerevan, Armenia, that present profound challenges to the control of disease through routine vaccination programmes. We draw on investigations of hesitancy towards the introduction of new vaccines, using the Human Papillomavirus (HPV) vaccine Gardasil as a case study, to interrogate underlying challenges to vaccine acceptance. We analyse primary data from the introduction of Gardasil, first used in Armenia in 2017, to investigate how levels of medical knowledge amongst physicians in 20 health facilities in Yerevan, Armenia, regarding vaccine science influence attitudes towards the introduction of a newly developed vaccine. A questionnaire-based cross-sectional study was completed by 348 physicians between December 2017 and September 2018. The responding physicians displayed a respectable level of knowledge and awareness regarding vaccination with respect to some characteristics (e.g., more than 81% knew that HPV infection was commonly asymptomatic, 73% knew that HPV infection was implicated in most cervical cancers, and 87% knew that cervical cancer is the most prevalent cancer amongst women) but low knowledge and poor understanding of other key issues such as the age at which women were most likely to develop cervical cancer (only 15% answered correctly), whether or not the vaccine should be administered to people who had already been infected (27% answered correctly) and whether sexually active young people should be treated for infection before vaccination (26% answered correctly). The study suggests that the drivers of vaccine hesitancy are complex and may not be consistent from vaccine to vaccine. The Armenian healthcare sector may need to provide additional training, awareness-raising and educational activities alongside the introduction of new vaccines to improve understanding of and trust in vaccination programmes.

Immunomodulatory Proteins in Tick Saliva From a Structural Perspective

To feed successfully, ticks must bypass or suppress the host’s defense mechanisms, particularly the immune system. To accomplish this, ticks secrete specialized immunomodulatory proteins into their saliva, just like many other blood-sucking parasites. However, the strategy of ticks is rather unique compared to their counterparts. Ticks’ tendency for gene duplication has led to a diverse arsenal of dozens of closely related proteins from several classes to modulate the immune system’s response. Among these are chemokine-binding proteins, complement pathways inhibitors, ion channels modulators, and numerous poorly characterized proteins whose functions are yet to be uncovered. Studying tick immunomodulatory proteins would not only help to elucidate tick-host relationships but would also provide a rich pool of potential candidates for the development of immunomodulatory intervention drugs and potentially new vaccines. In the present review, we will attempt to summarize novel findings on the salivary immunomodulatory proteins of ticks, focusing on biomolecular targets, structure-activity relationships, and the perspective of their development into therapeutics.

The Rise of Vectored Vaccines: A Legacy of the COVID-19 Global Crisis

The COVID-19 pandemic represents a milestone in vaccine research and development in a global context. A worldwide effort, as never seen before, involved scientists from all over the world in favor of the fast, accurate and precise construction and testing of immunogens against the new coronavirus, SARS-CoV-2. Among all the vaccine strategies put into play for study and validation, those based on recombinant viral vectors gained special attention due to their effectiveness, ease of production and the amplitude of the triggered immune responses. Some of these new vaccines have already been approved for emergency/full use, while others are still in pre- and clinical trials. In this article we will highlight what is behind adeno-associated vectors, such as those presented by the immunogens ChaAdOx1, Sputnik, Convidecia (CanSino, Tianjin, China), and Janssen (Johnson & Johnson, New Jersey, EUA), in addition to other promising platforms such as Vaccinia virus MVA, influenza virus, and measles virus, among others.