China
Africa
Explore chapters and articles related to this topic
Disease Prediction and Drug Development
Published in Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam, Introduction to Computational Health Informatics, 2019
Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam
Many types of vaccines are used. The traditional approach was to use attenuated virulent genes (disease-causing genes in pathogens) that are too weak to cause the disease but strong enough to invoke the immune response to counter the disease. Traditional vaccines can be: 1) live attenuated vaccine; 2) inactivated vaccine; 3) component vaccines; 4) VLP (virus-like particle) vaccine; 5) liposomal vaccines; 6) adjuvanted vaccines; 7) conjugate vaccine and 8) toxoid vaccine.
Adaptive humoral immunity and immunoprophylaxis
Published in Gabriel Virella, Medical Immunology, 2019
Conjugate vaccines. As previously mentioned, most polysaccharide vaccines have shown poor immunogenicity, particularly in infants. This lack of effectiveness is a consequence of the fact that polysaccharides induce mostly T-independent responses with little immunological memory. This problem appears to be eliminated if the polysaccharide is conjugated to an immunogenic protein, very much like a hapten-carrier conjugate. Hib conjugate vaccine. The first conjugate vaccines to be developed involved the polyribosyl-ribitol-phosphate (PRP) of Haemophilus influenzae type b (Hib). Four conjugate vaccines are available, based on Hib-polysaccharide conjugated to different protein carriers, such as diphtheria toxoid (PRP-D), a diphtheria toxoid-like protein (PRP-HbOC), tetanus toxoid (PRP-T), or meningococcal outer membrane protein (PRP-OMP). All are equally efficient, but to secure the carrier effect, critical for the boosting effect of repeated immunizations, the same vaccine should be used for the primary immunization and boosters.
Acute Otitis Media
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
Special attention should be drawn to children with or awaiting cochlear implants. Concern has been raised about a potential increased risk of pneumococcal meningitis, although whether it is implant-related or reflects inner ear abnormalities in many of these children is unclear. Most children will receive PCV13 through the Childhood Immunisation Schedule, and it is recommended that children with cochlear implants receive an additional single dose of pneumococcal polysaccharide vaccine (PPV23) after they reach 2 years of age. If the vaccines were not received, or the child was treated with PCV7 only, catch-up doses are recommended up to the age of 18 years. Hib conjugate vaccine is also recommended for all children up to the age of 5 years.35
Trends and health burden of hospitalized acute respiratory infections and impact of Haemophilus influenza immunization in a Tunisian university hospital: a twelve-year study
Published in Libyan Journal of Medicine, 2020
Manel Ben Fredj, Wafa Dhouib, Meriem Kacem, Cyrine Bennasrallah, Ons Mehrez, Hela Abroug, Imen Zemni, Aicha Gardabou, Koubaa Jamel, Slaheddine Chouchene, Naceur Rouatbi, Asma Belguith Sriha
However, there is no conclusive evidence of differences in the immune response to monovalent or combined Hib conjugate vaccines. In fact, a review about the successes and the contribution of hexavalent combination Hib vaccines in Europe from 2000 to 2014; showed a higher acceptance. On the other hand, there are some concerns that this combined form may reduce Hib immunogenicity [38]. Our results may be related to the high Hib vaccine coverage among children born since 2011. This high coverage vaccine provided by combined vaccines is explained by the reduction of injections number for babies and the reduction of visits to health-care centres. In addition, the effect of Hib Conjugate Vaccine on the prevention of pneumonia in hospitalized infants for bronchiolitis was shown by a case-control study [39]. In NVC, male children dominated Hib pneumonia admissions whereas no sex-difference was notified in VC, this result was concordant with conclusions in literature [40].
Relationship between immune response to pneumococcal conjugate vaccines in infants and indirect protection after vaccine implementation
Published in Expert Review of Vaccines, 2019
Efforts to expand the serotype range in the vaccine are ongoing, as currently extended serotype PCVs are being developing (from PCV15 [159] to PCV20 [160]). Inclusion of additional serotypes will aid further reduction of disease in the community, if the additional serotypes behave similarly to those in the current PCVs. However, the vaccines under development include additional serotypes that are all conjugated to a single carrier (mainly CRM197) [159]. Carrier protein overload with CRM197, which is antigenically related to diphtheria toxoid, presents the risk of interference, especially through the mechanism of carrier-induced epitope suppression [161]. Thus, in theory, the inclusion of more serotypes in a conjugate vaccine may result in lower antibody responses for some serotypes, resulting in reduced protection against carriage. Therefore, studies of vaccines under development must specifically investigate serotype-specific immune responses and their effect on the acquisition of vaccine serotypes. Such analyses will ensure continued community-wide reduction in disease.
Kingdon’s Multiple Streams Framework and the Analysis of Decision-Making Processes Regarding Publicly-Funded Immunization Programs.
Published in Expert Review of Vaccines, 2019
Philippe De Wals, Maria-Eugenia Espinoza-Moya, Daniel Béland
Two important characteristics of working groups and advisory committees are their years of experience and public presence and their willingness/reluctance to innovate. One of the strengths of the Québec Committee on Immunization over NACI and other provincial committees is the seniority of its members who, moreover, are used to working together and are familiar with all the issues and the success of a number of sometimes very innovative programs that depart from recommendations from vaccine manufacturers and NACI. For example, an immunization schedule consisting of two doses of the 10-valent pneumococcal conjugate vaccine followed by a toddler dose of the 13-valent pneumococcal conjugate vaccine was recommended [16]. Eventually, purchase contracts for this original and potentially cost-effective vaccination schedule could not be negotiated and the decision was made by the Ministry of Health to use the 10-valent pneumococcal conjugate vaccine and, at the same time, to improve the quality and timeliness of the surveillance system for invasive pneumococcal disease in the province in order to monitor carefully the epidemiology of the disease [17].