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Infections in Haematopoietic Stem Cell Transplants
Published in Firza Alexander Gronthoud, Practical Clinical Microbiology and Infectious Diseases, 2020
Even several months after engraftment, patients with allogenic transplants have an ongoing high risk of certain infections, and patients should be advised about contact precautions for respiratory viruses. Household contacts should receive inactivated influenza vaccine to reduce the potential for transmission. Live, attenuated influenza vaccine should not be used, owing to the risk of disease from this. For viral pneumonitis in which there is a paucity of other therapeutic options, polyvalent immunoglobulin may be of use alongside antiviral medications such as ribavirin.
Respiratory Diseases
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Aref T. Senno, Ryan K. Brannon
Annual influenza vaccination is the most effective method for preventing influenza infection and its complications [74]. The vaccine is reformulated yearly to cover the strains predicted to be in circulation and as a result has varying levels of efficacy. Large-scale studies examining vaccine efficacy in pregnancy are lacking, but a review of available evidence found vaccine efficacy of 41–91.5% reduction in laboratory-confirmed influenza [75]. The trivalent inactivated vaccine (TIV) for individuals is recommended for women who are pregnant, postpartum, or breastfeeding during the influenza season. TIV contains noninfectious killed viruses and cannot cause influenza. It can be given in any trimester of pregnancy. A meta-analysis examining the timing of influenza vaccine delivery showed a greater immune response is created later in pregnancy and that vaccination later in pregnancy led to increased maternal transfer of antibodies [76]. However, the optimal timing of influenza vaccine has not yet been determined and should thus be administered at the start of the influenza season, regardless of gestational age. There is no clear evidence of fetal harm after TIV administration to pregnant women [77] and no difference in rate of preterm birth and cesarean delivery [62]. In fact, influenza vaccination in the first trimester is not associated with an increase in major malformations rates and is associated with a decrease in stillbirth rates [78]. In addition to the protective effect of vaccination on women themselves, infants born to vaccinated mothers have fewer episodes of influenza, fever, and respiratory illness in their first 6 months of life [79], which may represent antibody transfer [80]. The live attenuated influenza vaccine (given intranasally), like other live-virus vaccines, should not be given during pregnancy (see also Chapter 40).
Next generation live-attenuated influenza vaccine platforms
Published in Expert Review of Vaccines, 2022
Among different strategies for LAIVs’ development, the ectodermal of influenza A M2e protein candidate vaccine is a potential target [132]. Two recombinant LAIV candidates (H1N1 + 4M2e and H3N2 + 4M2e) with four additional M2e tandem repeats were generated for enhanced cross-protection. The recombinant viruses showed similar growth characteristics to traditional LAIV viruses with robust M2e-specific antibodies response against heterologous influenza challenge in mice model. Similarly, induced M2e-specific antibodies in the ferret challenge provided increased cross-protection against the high-dose heterologous influenza viruses challenge [133]. In another study, a recombinant candidate H7N9 + 4M2e was generated for the expression of M2e-specific antibody [134]. The results suggest that the vaccine candidate provided increased protection against heterosubtypic influenza viruses challenge. In addition, experimental cold-adapted influenza reassortant chimeric A/B live attenuated influenza vaccine candidate generated [135]. Candidate vaccine induced IgG antibody responses against both influenza A and B viruses and provided protection against influenza B challenge in the mouse model.
Microneedles enable the development of skin-targeted vaccines against coronaviruses and influenza viruses
Published in Pharmaceutical Development and Technology, 2022
Thuy Trang Nguyen, Thi Thuy Dung Nguyen, Nguyen-Minh-An Tran, Huy Truong Nguyen, Giau Van Vo
The SARS-CoV-1, SARS-CoV-2 and influenza are well known to cause contagious respiratory illnesses and share some symptoms such as coughing, fever, and tiredness. Influenza viruses are enveloped viruses of the Orthomyxoviridae family, which are grouped into four genera, which include influenza virus A–D (IAV, IBV, ICV, and IDV). Among influenza viruses, type A and B v such as influenza A (H1N1) and influenza A (H3N2) have been recognized as a seasonal epidemics of the disease. Among the species, the emergence of pandemic H1N1 influenza in 2009, human infections with avian H7N9 influenza in 2013, and sporadic human cases of highly pathogenic avian H5N1 influenza (Webster and Govorkova 2014). Currently, two available influenza vaccines have been marketed including the trivalent inactivated influenza vaccine (TIV) administered intramuscularly with syringes for using in ages > 6 months old and the live attenuated influenza vaccine (LIV) are provided as nasal spray. However, available influenza prevention through immunization in adults is hindered by low vaccination coverage, high immunization costs (Lee et al. 2015), and suboptimum vaccine effectiveness (Osterholm et al. 2012). Although many types of influenza vaccines are currently approved, improved delivery methods are needed to tackle these limitations.
Approaches in broadening the neutralizing antibody response of the influenza vaccine
Published in Expert Review of Vaccines, 2021
Ruiqi Zhang, Ivan Fan-Ngai Hung
After the 1918 flu pandemic, scientists have tried to develop influenza vaccine. In 1936, Smorodintseff et al. attempted to vaccinate 72 volunteers with live influenza virus, and a majority of cases without clinical symptoms developed high level of specific antibodies [23,24]. The virus used by Smorodintseff had been passed on eggs for several times and showed attenuated virulence [23]. From then on, attenuated influenza virus was used to produce a live attenuated influenza vaccine. Besides, many attempts have been made to develop a new type of vaccine. For instance, during the Second World War, scientists from U.S.A. and UK tried to study inactivated influenza vaccine. In 1942, the first inactivated vaccine, a bivalent influenza vaccine, was administrated in people [24]. Currently, there are three main types of influenza vaccine available to humans: inactivated vaccine, attenuated influenza vaccine, and recombinant HA vaccine [25].