China
Africa
Explore chapters and articles related to this topic
The 1918 Influenza A Pandemic
Published in Patricia G. Melloy, Viruses and Society, 2023
Will we ever have a universal flu vaccine? In the past, a universal flu vaccine which can be used every flu season has been hard to develop because of how rapidly influenza mutates into different strains (Brown 2018; Lostroh 2019). Researchers have explored using other proteins of the virus such as a stalk protein or an ion channel protein as the immunogen in a universal flu vaccine, since these genes may not mutate as quickly as the genes encoding hemagglutinin and neuraminidase. However, getting these other parts of the virus to invoke a strong immune response with vaccination has been challenging, but different recombinant protein vaccines are being explored (Lostroh 2019). Other scientists are looking at what contributing factors might make a seasonal flu vaccine less effective in one person versus another. Characteristics like age, biological sex, obesity, and even perhaps one’s microbiome may have an effect, in addition to previous exposures to influenza virus as mentioned earlier (Dhakal and Klein 2019). In addition to finding the best possible vaccine to elicit a sufficient universal immune response, physicians will need to look at these other aspects of the patient profile to help improve the effectiveness of a universal flu vaccine.
The Great Influenza
Published in Rae-Ellen W. Kavey, Allison B. Kavey, Viral Pandemics, 2020
Rae-Ellen W. Kavey, Allison B. Kavey
Moving forward, a new approach to influenza vaccine development is clearly indicated. In response to this pressure, there have been efforts to develop a universal flu vaccine that would convey durable cross-protective immunity against diverse virus strains dating back many years. Studies in animal models show that using relatively invariant parts of the virus can induce immunity with the most promising approaches based on antibodies specific for the relatively conserved ectodomain of matrix protein 2 and the infra-subunit region of hemagglutinin.77 Multiple teams have taken up the challenge of developing a safe and effective universal influenza vaccine, using a wide variety of strategies including vaccine-induced antibodies against the HA stem, blockage of interferon evasion genes with a constructed virus, and antibodies that bind to the influenza virus and recruit T cells to destroy infected cells.78–83
Communicable diseases
Published in Liam J. Donaldson, Paul D. Rutter, Donaldsons' Essential Public Health, 2017
Liam J. Donaldson, Paul D. Rutter
Among the many candidate vaccines currently under development, the most exciting prospects include vaccines against HIV and malaria. There is also potential for a universal flu vaccine that would protect against seasonal flu without the need for annual revaccination and also against newly emerging flu viruses that could otherwise cause pandemics. None of these vaccines are imminent, but in each case, a number of candidate vaccines are progressing through trials.
Determining optimal community protection strategies for the influenza vaccine
Published in Expert Review of Vaccines, 2019
Charlotte Switzer, Lorne Babiuk, Mark Loeb
Following the waning of maternally acquired antibodies, further studies have evaluated the impact of priming on influenza vaccine efficacy [93–96]. A study of children receiving complete or partial vaccinations across the 2011–2013 influenza seasons did not find higher VE between the two groups [93]. However, children who had received two vaccine doses in the same prior season had significantly higher estimates of VE (58–80%), as compared to children who did not (33–44%). This may also be explained by cross-protection across strains, or residual efficacy from previous exposures. The issues of cross-reactivity, antigenic shift and drift, immunological interference and waning immunity will continue to challenge the development of a priming strategy for influenza vaccination. Despite progress towards a universal flu vaccine, and increased measures of virological surveillance to support antigenically matched vaccine formulations, these challenges will continue to counter public health measures to reduce the burden of influenza. While herd immunity will remain an important factor in developing targeted immunization campaigns, the mutable nature of influenza infection and immunity is a clear example of the importance of direct protection. Key next steps for achieving the global reduction of influenza-associated morbidity and mortality will require focused efforts on targeting vaccination campaigns and awareness towards highly susceptible and transmission-dynamic populations, with the priority of protecting school-aged children.
News Briefs
Published in Journal of Community Health Nursing, 2019
Progress has been made in four areas: a) monitoring and detection, b) risk assessment, c) prevention and treatment, and d) international work, according to the CDC report. In the area of monitoring and detection, the CDC has expanded and improved influenza surveillance. For example, standardized sampling practices for flu across public health and clinical laboratories have been implemented, all flu virus samples submitted to the CDC undergo full genetic sequencing, and three regional reference centers have been established in order to streamline and standardize data collection practices. In the area of risk assessment, the CDC has developed new assessment tools to inform public health actions, including one that assesses the pandemic potential of a novel flu virus. In the area of prevention and treatment, significant progress has been made during the decade since 2009, according to the CDC. New vaccine technologies have been created and the capacity for vaccine production has been expanded. There is investment and ongoing research into the production of a universal flu vaccine. In addition, more drugs to treat flu are available, including a new class of influenza antiviral drugs. In the area of international work, the CDC is collaborating with worldwide partners, including the World Health Organization, to create a global response to pandemic influenza. According to the CDC, in the past 10 years, it has worked with 37 countries to support improvements in flu virus detection and to help strengthen public health services. The CDC summary of progress on pandemic influenza was retrieved on 19 June 2019 at https://www.cdc.gov/flu/pandemic-resources/h1n1-summary.htm?deliveryName=USCDC_201-DM2209.
Current challenges: from the path of “original antigenic sin” towards the development of universal flu vaccines
Published in International Reviews of Immunology, 2020
Asim Biswas, Alok K. Chakrabarti, Shanta Dutta
The amelioration of influenza infection leading to virus clearance depends on both B-cell and T-cell responses. Influenza epidemic and pandemic frequently occur due to the inherent capacity of the virus to evolve in a pretty short interval through mutation or cross-species transmission. These changes within viral proteins make vaccination or antiviral therapy less or otherwise wholly ineffective. Therefore, the concept of a universal flu vaccine is defined by their ability to elicit broad and prolong immune responses to neutralize diverse strains of influenza viruses and counteract their pathogenic effect. Most of the existing influenza vaccines induce humoral responses mainly toward antigenically variable immune dominant head region of the HA protein, whereas anti-NA antibody can interfere with its neuraminidase activity either during budding of progeny particle or respiratory pathway clearance to interact virus with host cellular sialic acid receptor [68,69]. Rapid mutation at the antibody binding site due to inherent tolerogenicity of the escape mutant makes these vaccines ineffective with the appearance of drifted strains. HA molecule consists of two regions, i.e. head and stalk, and amino acid sequence analysis of different HAs has found relatively higher epitope conservation in the stalk region than in the head region [70,71]. Head epitopes of a HA molecule are inherently immune dominant and may force immune system to produce antibodies more toward highly mutable head region of the HA during natural infection or after vaccination [72,73]. The mechanism of immunodominance depends on the physical attachment of head to stem which creates physical hindrances to interaction of B-cell receptors with stem epitopes during B-cell differentiation [74,75]. Efforts are ongoing in flu vaccine research to force host immune system to produce neutralizing antibodies which can interact with relatively subdominant conserved stalk epitopes so that extensive protection can be achieved toward dissimilar flu strains emanated from human, swine and avian species.