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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.
Respiratory Diseases
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Aref T. Senno, Ryan K. Brannon
Annual epidemics of influenza typically occur during the late fall through early spring: In the Northern Hemisphere, flu season starts in September or October and may continue as late as May. In addition to seasonal influenza, epidemics or pandemics arise unpredictably. The pattern of emergence is usually in the Southern Hemisphere first, during the austral winter, where seasonal influenza peaks in August. A systematic review examining the incidence of influenza among pregnant patients showed that rates varied widely across regions and years. Estimates of serology-confirmed influenza cases range from 483 to 1097 cases per 10,000 pregnant women [53–55]. Symptomatic cases however tend to be far less. In the United States, symptomatic influenza ranged from 0.1 to 6.6 cases per 10,000 pregnancies during the 2009 pandemic [56, 57].
Respiratory Infections
Published in Miriam Orcutt, Clare Shortall, Sarah Walpole, Aula Abbara, Sylvia Garry, Rita Issa, Alimuddin Zumla, Ibrahim Abubakar, Handbook of Refugee Health, 2021
Viruses are responsible for about 60% of cases, including influenza A and B, parainfluenza, rhinovirus, coronavirus, RSV and human metapneumovirus. Causative bacteria include Bordetella pertussis, Mycoplasma pneumoniae and Chlamydia pneumoniae. Consider (and treat) influenza in the ‘flu season’. Suspect pertussis (whooping cough) if the patient has the characteristic cough (high-pitched ‘whoop’ or gasp with fits of coughing).
Management of influenza – updated Swedish guidelines for antiviral treatment
Published in Infectious Diseases, 2023
Johan Westin, Emmi Andersson, Malin Bengnér, Anna Berggren, Mia Brytting, Erica Ginström Ernstad, Anna C. Nilsson, Martina Wahllöf, Gabriel Westman, Maria Furberg
For people belonging to risk groups, but who for some reason cannot be vaccinated, and for immunocompromised persons with an expected low/non protective effect of the vaccine, additional precautionary measures are recommended, such as avoiding close contact with potentially infectious individuals, especially during flu season.Influenza types that can cause symptomatic infection and spread between humans.A(H1N1)pdm09 debuted during the pandemic 2009A(H3N2)B/VictoriaB/YamagataA(H1N1) (not circulating since 2009)
Testing for genetic mutation of seasonal influenza virus
Published in Journal of Applied Statistics, 2023
HA mediates the entry of a virus into the cell and the corresponding antibody protects the body from illness; while NA facilitates the spread of a virus among the cells and its antibody generally reduces the severity of illness; [25]. Accordingly, flu vaccines are developed each year to protect the general public against infections .3 A flu vaccine is made up from a collection of strains of virus observed in previous years that are predicted to circulate in the upcoming flu season, and would therefore provide an effective protection if the vaccine shot is administrated ahead of time. For example, it has been suggested that the 2019/20 flu vaccine contains an A/Brisbane/02/2018 (H1N1)pdm09 like virus, an A/Kansas/14/2017 (H3N2) like virus, a B/Colorado/06/2017 like virus, and a B/Phuket/3073/2013 like virus, according to the World Health Organization. To what extent the vaccine is effective depends on whether there is a good match between the strains selected, as parts of a vaccine, and the current circulating strain.
Immunization and Drug Metabolizing Enzymes: Focus on Hepatic Cytochrome P450 3A
Published in Expert Review of Vaccines, 2021
Kristina Jonsson-Schmunk, Romi Ghose, Maria A. Croyle
Of the 42,483 influenza-positive tests reported to CDC by clinical laboratories during the 2018–2019 flu season, 96% of cases were the result of infection with influenza A viruses (54.3% H1N1, 41.7% H3N2 subtypes) [34]. To understand if these subtypes of influenza A viruses can impact CYP3A4 activity, initial pilot studies were conducted with these viruses at relatively low MOI (50 and 100). Significant cytotoxicity associated with virus infection was noted within 72 hours (data not shown); thus, changes in CYP3A4 expression and function in response to influenza were evaluated 48 hours after infection. Infection with the H1N1 virus almost completely suppressed CYP3A4 activity (91% reduction for an MOI of 50 and 95% for an MOI of 100 with respect to uninfected cells; Figure 2B). Similar changes in CYP3A4 activity were observed for the H3N2 subtype (90% reduction, MOI 50, 87% reduction, MOI 100; Figure 2C). As for the adenovirus studies, the lowest virus concentration (MOI 50) was used for the remaining experiments in order to minimize confounding results due to virus-mediated cell death. Viral entry (and replication in this case) for both H1N1 and H3N2 influenza subtypes was also confirmed by qRT-PCR with an average amount of 1,185 ± 523 CEID50/cell and 755 ± 175 CEID50/cell detected, respectively, in HC-04 cells infected for 48 hours.