Final Report Summary - OMVAC (Novel prevention and treatment possibilities for Otitis Media through the comprehensive identification of antigenic proteins)
Approximately 80 % of all children undergo an Otitis media (OM) episode by three years of age. The main causative agents are the bacterial pathogens Streptococcus pneumoniae, Haemophilus influenza and Moraxella catarrhalis which colonise the middle ear, often after a primary viral infection. After introduction and widespread use of pneumococcal vaccines, there is evidence that the impact of the latter two species increased. Acute otitis media (AOM) is characterised by the presence of middle ear effusion accompanied by the rapid onset of signs of inflammation such as otalgia, otorrhea or fever. Recurrent OM affects up to 40 % of children and may persist for weeks to months causing symptoms ranging from hearing loss and tinnitus to anorexia or conjunctivitis. As AOM is very painful, it results very often in antibiotic treatment although solid evidence is lacking that this therapy alters the course of OM disease in children. Also in case of recurrent OM, the failure rate of antibiotic therapy is quite high, often due to antibiotic resistances of the pathogens. Considering also the high direct and indirect costs of OM, there is an urgent need for an alternative and effective therapy.
The main goal of the OMVAC project was the identification of candidate Moraxella catarrhalis (Mcat) and non-typeable Haemophilus influenzae (NTHi) protein antigens suitable for the development of a prophylactic vaccine to prevent OM in children.
The OMVAC project succeeded in identifying and filing patent applications for a large set of Mcat and NTHi protein antigens. Based on serological, genetic, bioinformatic and patentability-based antigen validation, NTHi and Mcat proteins were generated in pure, recombinant form for efficacy testing in preclinical animal models. The OMVAC antigens were compared with previously published benchmark proteins in preclinical mouse models, and lead candidates were identified that performed better than the benchmark proteins or killed bacteria (the latter a strong positive control in mouse models). Thus, the NTHi and Mcat antigens identified under OMVAC appear to compare favourable with state-of-the-art benchmark antigens.
In parallel activities, the NTHi and Mcat protein antigens were validated by molecular microbiology means (e.g. generation of gene deletion knockouts and functional protein studies), and the human immune responses directed against these antigens during OM were examined.
Thus, in short, OMVAC reached the major objective: The project identified and filed patent applications for new NTHi and Mcat protein antigens. OMVAC was not intended to deliver a complete preclinical package for all identified NTHi and Mcat antigens. A substantial amount of work is still needed to generate the preclinical efficacy and safety data necessary for e.g. clinical entry of the NTHi and Mcat antigens identified under OMVAC. This post-OMVAC preclinical antigen development is currently ongoing, based on the solid knowledge and network foundation provided by the OMVAC project.
A number of NTHi candidate vaccine antigens have been identified previously. However, as regards protein-based vaccine antigens, these candidate antigens comprise essentially the 10 most abundant NTHi surface proteins. Similarly, a number of candidate Mcat vaccine antigens have been identified, but these approximately 15 candidate antigens comprise essentially a sample of the most abundant Mcat surface proteins.
Furthermore, the NTHi and Mcat antigens identified under OMVAC have been compared with clinically evaluated or published benchmark proteins in preclinical mouse models, and for both NTHi and Mcat proteins identified under OMVAC, lead candidates have been identified that performed better than those clinically evaluated or published benchmark NTHi and Mcat proteins. In fact, for NTHi proteins identified under OMVAC, lead candidates have been selected that performed as well as or better than inactivated bacterial antigen (a strong positive control in mouse models).
The main goal of the OMVAC project was the identification of candidate Moraxella catarrhalis (Mcat) and non-typeable Haemophilus influenzae (NTHi) protein antigens suitable for the development of a prophylactic vaccine to prevent OM in children.
The OMVAC project succeeded in identifying and filing patent applications for a large set of Mcat and NTHi protein antigens. Based on serological, genetic, bioinformatic and patentability-based antigen validation, NTHi and Mcat proteins were generated in pure, recombinant form for efficacy testing in preclinical animal models. The OMVAC antigens were compared with previously published benchmark proteins in preclinical mouse models, and lead candidates were identified that performed better than the benchmark proteins or killed bacteria (the latter a strong positive control in mouse models). Thus, the NTHi and Mcat antigens identified under OMVAC appear to compare favourable with state-of-the-art benchmark antigens.
In parallel activities, the NTHi and Mcat protein antigens were validated by molecular microbiology means (e.g. generation of gene deletion knockouts and functional protein studies), and the human immune responses directed against these antigens during OM were examined.
Thus, in short, OMVAC reached the major objective: The project identified and filed patent applications for new NTHi and Mcat protein antigens. OMVAC was not intended to deliver a complete preclinical package for all identified NTHi and Mcat antigens. A substantial amount of work is still needed to generate the preclinical efficacy and safety data necessary for e.g. clinical entry of the NTHi and Mcat antigens identified under OMVAC. This post-OMVAC preclinical antigen development is currently ongoing, based on the solid knowledge and network foundation provided by the OMVAC project.
A number of NTHi candidate vaccine antigens have been identified previously. However, as regards protein-based vaccine antigens, these candidate antigens comprise essentially the 10 most abundant NTHi surface proteins. Similarly, a number of candidate Mcat vaccine antigens have been identified, but these approximately 15 candidate antigens comprise essentially a sample of the most abundant Mcat surface proteins.
Furthermore, the NTHi and Mcat antigens identified under OMVAC have been compared with clinically evaluated or published benchmark proteins in preclinical mouse models, and for both NTHi and Mcat proteins identified under OMVAC, lead candidates have been identified that performed better than those clinically evaluated or published benchmark NTHi and Mcat proteins. In fact, for NTHi proteins identified under OMVAC, lead candidates have been selected that performed as well as or better than inactivated bacterial antigen (a strong positive control in mouse models).
