Pre-pandemic and pandemic influenza vaccines

Assessment of Antigen-Specific and Cross-Reactive Antibody Responses to an MF59-Adjuvanted A/H5N1 Prepandemic Influenza Vaccine in Adult and Elderly Subjects

“…These findings emphasize the need to prepare for potential avian influenza pandemics. Proactive priming in those who have not encountered the A/H5N1 influenza virus serves to equip the individual with A/H5N1-specific memory lymphocyte populations and decrease the number of vaccinations required in the event of a pandemic (16,26). This clinical trial evaluated the immunogenicity and safety profiles of Antibody responses against the vaccine antigen strain were sufficient to meet the European licensure criteria after two doses in both adult and elderly subjects.…”

Use of recombinant flagellin in oil-in-water emulsions enhances hemagglutinin-specific mucosal IgA production and IL-17 secreting T cells against H5N1 avian influenza virus infection

“…HPAI H5N1 viruses mainly infect the lower respiratory tract, resulting in lung damage and plasma cytokine dysregulation [2,3]. The first human HPAI H5N1 case, identified in Hong Kong in 1997, re-emerged in 2003 and has infected individuals in Asia, the Middle East, Europe, and Africa; the mortality rate in these incidences is approximately 60% [1,[4][5][6].…”

Vaccination against influenza: role and limitations in pandemic intervention plans

“…It has been estimated that prepandemic priming 20% of a population would prevent as much morbidity as immunizing 60% of the population if vaccine is not provided until after the first pandemic wave [50]. However, prepandemic vaccine usefulness may be limited if cross-reactivity between the prepandemic and pandemic strains is not sufficient [48]. Modeling research also indicates that the effectiveness of priming may be decreased if the first of a two-dose prepandemic vaccine is not administered until after the first case of pandemic influenza is identified [18]; priming is believed to be most effective if the first dose is given during the prepandemic period.…”

“…For example, those over the age of 65 years were shown to have some immunity to 2009 H1N1 [25], which negated the need to immunize these individuals or made their vaccination a lower priority than younger people. Thus, it is now recognized that priming of the population using prepandemic vaccines is another option for creating pre-existing immunity that may increase pandemic influenza vaccine efficacy or minimize morbidity and mortality while a pandemic vaccine is being created and tested [48].…”

“…Prepandemic vaccine development in the 2000s, therefore, focused on H5N1 strains [24,25,52]. The 2009 H1N1 pandemic took the scientific world by surprise [48], necessitating rapid development of a new vaccine. Likewise, the 1957 and 1968 pandemic strains occurred without warning [6], which makes priming based on viral surface proteins problematic.…”