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318 KiB

Open AccessArticle

Beliefs and Opinions of Health Care Workers and Students Regarding Influenza and Influenza Vaccination in Tuscany, Central Italy

by Guglielmo Bonaccorsi, Francesca Santomauro, Barbara Rita Porchia, Giuditta Niccolai, Elettra Pellegrino, Paolo Bonanni and Chiara Lorini

Vaccines 2015, 3(1), 137-147; https://doi.org/10.3390/vaccines3010137 - 26 Feb 2015

Cited by 36 | Viewed by 6981

Abstract

Immunization of health care workers (HCWs) against influenza has been associated with improvements in patient safety. The aim of this study is to assess the beliefs, attitudes, and knowledge of HCWs and health profession students regarding influenza. An anonymous questionnaire was distributed to [...] Read more.

Immunization of health care workers (HCWs) against influenza has been associated with improvements in patient safety. The aim of this study is to assess the beliefs, attitudes, and knowledge of HCWs and health profession students regarding influenza. An anonymous questionnaire was distributed to HCWs in three local Florentine healthcare units, at Careggi University Teaching Hospital, and to students in health profession degree programs. A total of 2576 questionnaires were fully completed. A total of 12.3% of subjects responded that they were “always vaccinated” in all three of the seasonal vaccination campaigns studied (2007–2008 to 2009–2010), 13.1% had been vaccinated once or twice, and 74.6% had not received vaccinations. Although the enrolled subjects tended to respond that they were “never vaccinated,” they considered influenza to be a serious illness and believed that the influenza vaccine is effective. The subjects who refused vaccination more frequently believed that the vaccine could cause influenza and that it could have serious side effects. More than 60% of the “always vaccinated” group completely agreed that HCWs should be vaccinated. Self-protection and protecting family members or other people close to the respondent from being infected and representing potential sources of influenza infection can be considered motivating factors for vaccination. The results highlight the importance of improving vaccination rates among all HCWs through multi-component interventions. Knowledge of influenza should be reinforced. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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Review

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555 KiB

Open AccessReview

Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

by Saranya Sridhar, Karl A. Brokstad and Rebecca J. Cox

Vaccines 2015, 3(2), 373-389; https://doi.org/10.3390/vaccines3020373 - 24 Apr 2015

Cited by 136 | Viewed by 21755

Abstract

Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people [...] Read more.

Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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1053 KiB

Open AccessReview

Measuring Cellular Immunity to Influenza: Methods of Detection, Applications and Challenges

by Lynda Coughlan and Teresa Lambe

Vaccines 2015, 3(2), 293-319; https://doi.org/10.3390/vaccines3020293 - 14 Apr 2015

Cited by 27 | Viewed by 14773

Abstract

Influenza A virus is a respiratory pathogen which causes both seasonal epidemics and occasional pandemics; infection continues to be a significant cause of mortality worldwide. Current influenza vaccines principally stimulate humoral immune responses that are largely directed towards the variant surface antigens of [...] Read more.

Influenza A virus is a respiratory pathogen which causes both seasonal epidemics and occasional pandemics; infection continues to be a significant cause of mortality worldwide. Current influenza vaccines principally stimulate humoral immune responses that are largely directed towards the variant surface antigens of influenza. Vaccination can result in an effective, albeit strain-specific antibody response and there is a need for vaccines that can provide superior, long-lasting immunity to influenza. Vaccination approaches targeting conserved viral antigens have the potential to provide broadly cross-reactive, heterosubtypic immunity to diverse influenza viruses. However, the field lacks consensus on the correlates of protection for cellular immunity in reducing severe influenza infection, transmission or disease outcome. Furthermore, unlike serological methods such as the standardized haemagglutination inhibition assay, there remains a large degree of variation in both the types of assays and method of reporting cellular outputs. T-cell directed immunity has long been known to play a role in ameliorating the severity and/or duration of influenza infection, but the precise phenotype, magnitude and longevity of the requisite protective response is unclear. In order to progress the development of universal influenza vaccines, it is critical to standardize assays across sites to facilitate direct comparisons between clinical trials. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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430 KiB

Open AccessReview

Developing Universal Influenza Vaccines: Hitting the Nail, Not Just on the Head

by Lidewij C. M. Wiersma, Guus F. Rimmelzwaan and Rory D. De Vries

Vaccines 2015, 3(2), 239-262; https://doi.org/10.3390/vaccines3020239 - 26 Mar 2015

Cited by 41 | Viewed by 8694

Abstract

Influenza viruses have a huge impact on public health. Current influenza vaccines need to be updated annually and protect poorly against antigenic drift variants or novel emerging subtypes. Vaccination against influenza can be improved in two important ways, either by inducing more broadly [...] Read more.

Influenza viruses have a huge impact on public health. Current influenza vaccines need to be updated annually and protect poorly against antigenic drift variants or novel emerging subtypes. Vaccination against influenza can be improved in two important ways, either by inducing more broadly protective immune responses or by decreasing the time of vaccine production, which is relevant especially during a pandemic outbreak. In this review, we outline the current efforts to develop so-called “universal influenza vaccines”, describing antigens that may induce broadly protective immunity and novel vaccine production platforms that facilitate timely availability of vaccines. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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Open AccessReview

Emerging Influenza Strains in the Last Two Decades: A Threat of a New Pandemic?

by Claudia Trombetta, Simona Piccirella, Daniele Perini, Otfried Kistner and Emanuele Montomoli

Vaccines 2015, 3(1), 172-185; https://doi.org/10.3390/vaccines3010172 - 18 Mar 2015

Cited by 36 | Viewed by 7864

Abstract

In the last 20 years, novel non-seasonal influenza viruses have emerged, most of which have originated from birds. Despite their apparent inability to cause pandemics, with the exception of H1N1 swine influenza virus, these viruses still constitute a constant threat to public health. [...] Read more.

In the last 20 years, novel non-seasonal influenza viruses have emerged, most of which have originated from birds. Despite their apparent inability to cause pandemics, with the exception of H1N1 swine influenza virus, these viruses still constitute a constant threat to public health. While general concern has decreased after the peak of the H5N1 virus, in recent years several novel reassorted influenza viruses (e.g., H7N9, H9N2, H10N8) have jumped the host-species barrier and are under surveillance by the scientific community and public health systems. It is still unclear whether these viruses can actually cause pandemics or just isolated episodes. The purpose of this review is to provide an overview of old and novel potential pandemic strains of recent decades. Full article

(This article belongs to the Special Issue Influenza Vaccines)

913 KiB

Open AccessReview

M2e-Based Universal Influenza A Vaccines

by Lei Deng, Ki Joon Cho, Walter Fiers and Xavier Saelens

Vaccines 2015, 3(1), 105-136; https://doi.org/10.3390/vaccines3010105 - 13 Feb 2015

Cited by 140 | Viewed by 17505

Abstract

The successful isolation of a human influenza virus in 1933 was soon followed by the first attempts to develop an influenza vaccine. Nowadays, vaccination is still the most effective method to prevent human influenza disease. However, licensed influenza vaccines offer protection against antigenically [...] Read more.

The successful isolation of a human influenza virus in 1933 was soon followed by the first attempts to develop an influenza vaccine. Nowadays, vaccination is still the most effective method to prevent human influenza disease. However, licensed influenza vaccines offer protection against antigenically matching viruses, and the composition of these vaccines needs to be updated nearly every year. Vaccines that target conserved epitopes of influenza viruses would in principle not require such updating and would probably have a considerable positive impact on global human health in case of a pandemic outbreak. The extracellular domain of Matrix 2 (M2e) protein is an evolutionarily conserved region in influenza A viruses and a promising epitope for designing a universal influenza vaccine. Here we review the seminal and recent studies that focused on M2e as a vaccine antigen. We address the mechanism of action and the clinical development of M2e-vaccines. Finally, we try to foresee how M2e-based vaccines could be implemented clinically in the future. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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312 KiB

Open AccessReview

Assaying the Potency of Influenza Vaccines

by Philip D. Minor

Vaccines 2015, 3(1), 90-104; https://doi.org/10.3390/vaccines3010090 - 05 Feb 2015

Cited by 50 | Viewed by 8474

Abstract

The potency of vaccines must be determined to ensure that the appropriate dose is given. The manufacture and assessment of influenza vaccines are complicated by the continuously changing nature of the pathogen, which makes efficacy estimates difficult but also confounds attempts to produce [...] Read more.

The potency of vaccines must be determined to ensure that the appropriate dose is given. The manufacture and assessment of influenza vaccines are complicated by the continuously changing nature of the pathogen, which makes efficacy estimates difficult but also confounds attempts to produce a well-validated, consistent potency assay. Single radial diffusion has been used for decades and provides a relatively simple way to measure the amount of biologically active materials present in the vaccine. It requires reagents, which are updated on a regular, frequently yearly, basis and alternative methods continue to be sought. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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841 KiB

Open AccessReview

Optimal Use of Vaccines for Control of Influenza A Virus in Swine

by Matthew R. Sandbulte, Anna R. Spickler, Pamela K. Zaabel and James A. Roth

Vaccines 2015, 3(1), 22-73; https://doi.org/10.3390/vaccines3010022 - 30 Jan 2015

Cited by 77 | Viewed by 14870

Abstract

Influenza A virus in swine (IAV-S) is one of the most important infectious disease agents of swine in North America. In addition to the economic burden of IAV-S to the swine industry, the zoonotic potential of IAV-S sometimes leads to serious public health [...] Read more.

Influenza A virus in swine (IAV-S) is one of the most important infectious disease agents of swine in North America. In addition to the economic burden of IAV-S to the swine industry, the zoonotic potential of IAV-S sometimes leads to serious public health concerns. Adjuvanted, inactivated vaccines have been licensed in the United States for over 20 years, and there is also widespread usage of autogenous/custom IAV-S vaccines. Vaccination induces neutralizing antibodies and protection against infection with very similar strains. However, IAV-S strains are so diverse and prone to mutation that these vaccines often have disappointing efficacy in the field. This scientific review was developed to help veterinarians and others to identify the best available IAV-S vaccine for a particular infected herd. We describe key principles of IAV-S structure and replication, protective immunity, currently available vaccines, and vaccine technologies that show promise for the future. We discuss strategies to optimize the use of available IAV-S vaccines, based on information gathered from modern diagnostics and surveillance programs. Improvements in IAV-S immunization strategies, in both the short term and long term, will benefit swine health and productivity and potentially reduce risks to public health. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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512 KiB

Open AccessReview

Overview of Serological Techniques for Influenza Vaccine Evaluation: Past, Present and Future

by Claudia Maria Trombetta, Daniele Perini, Stuart Mather, Nigel Temperton and Emanuele Montomoli

Vaccines 2014, 2(4), 707-734; https://doi.org/10.3390/vaccines2040707 - 13 Oct 2014

Cited by 78 | Viewed by 13314

Abstract

Serological techniques commonly used to quantify influenza-specific antibodies include the Haemagglutination Inhibition (HI), Single Radial Haemolysis (SRH) and Virus Neutralization (VN) assays. HI and SRH are established and reproducible techniques, whereas VN is more demanding. Every new influenza vaccine needs to fulfil the [...] Read more.

Serological techniques commonly used to quantify influenza-specific antibodies include the Haemagglutination Inhibition (HI), Single Radial Haemolysis (SRH) and Virus Neutralization (VN) assays. HI and SRH are established and reproducible techniques, whereas VN is more demanding. Every new influenza vaccine needs to fulfil the strict criteria issued by the European Medicines Agency (EMA) in order to be licensed. These criteria currently apply exclusively to SRH and HI assays and refer to two different target groups—healthy adults and the elderly, but other vaccine recipient age groups have not been considered (i.e., children). The purpose of this timely review is to highlight the current scenario on correlates of protection concerning influenza vaccines and underline the need to revise the criteria and assays currently in use. In addition to SRH and HI assays, the technical advantages provided by other techniques such as the VN assay, pseudotype-based neutralization assay, neuraminidase and cell-mediated immunity assays need to be considered and regulated via EMA criteria, considering the many significant advantages that they could offer for the development of effective vaccines. Full article

(This article belongs to the Special Issue Influenza Vaccines)

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