The real cost of an affordable vaccine for meningococcus A

Abstract

In their Viewpoint, Luis Jodar and colleagues (May 31, p 1902)1Jodar L LaForce FM Ceccarini C Aguado T Granoff DM Meningococcal conjugate vaccine for Africa: a model for development of new vaccines for the poorest countries..Lancet. 2003; 361: 1902-1904Summary Full Text Full Text PDF PubMed Scopus (85) Google Scholar describe a new model for development of vaccines, which could speed up the process of their availability in developing countries. Although I agree the model they propose is potentially good and worth exploring, I am not sure the aim to develop the lowest price vaccine possible was the right choice. In fact, I believe that this aim has already delayed the progress of a vaccine for meningococcal A vaccine in Africa by a decade. In 1991, a combination vaccine, containing conjugated vaccine against meningococcus serogroups A and C, was tested in a phase 1 study with promising results.2Costantino P Viti S Podda A Velmonte MA Nencioni L Rappuoli R Development and phase 1 clinical testing of a conjugate vaccine against meningococcus A and C..Vaccine. 1992; 10: 691-698Crossref PubMed Scopus (147) Google Scholar The combination vaccine was designed to cover the most prevalent serogroups, serogroup C being prevalent in Europe and the USA and serogroup A in Africa. The same lot of combined AC conjugate vaccine was subsequently tested in several clinical trials.3Lieberman JM Chiu SS Wong VK et al.Safety and immunogenicity of a serogroups A/C Neisseria meningitidis oligosaccharideprotein conjugate vaccine in young children: a randomized controlled trial..JAMA. 1996; 275: 1499-1503Crossref PubMed Google Scholar, 4Borrow R Fox AJ Richmond PC et al.Induction of immunological memory in UK infants by a meningococcal A/C conjugate vaccine..Epidemiol Infect. 2000; 124: 427-432Crossref PubMed Scopus (38) Google Scholar With the exception of some doubts about the serogroup A vaccine in The Gambia, all studies proved that conjugate vaccines were able to induce protective concentrations of bactericidal antibodies and immunological memory in all age groups. They were, therefore, able to overcome the limits of the existing polysaccharide vaccines, which, being poorly efficacious in infants and young children and unable to induce immunological memory, had not been used for mass vaccination. The results encouraged the accelerated development and implementation of a conjugate vaccine against meningococcus C in the UK, which in 1999–2000 vaccinated the entire population aged 2 months to 18 years, and successfully eliminated the disease.5Ramsay ME Andrews N Kaczmarski EB Miller E Efficacy of meningococcal serogroup C conjugate vaccine in teenagers and toddlers in England..Lancet. 2001; 357: 195-196Summary Full Text Full Text PDF PubMed Scopus (303) Google Scholar However, there was no interest from the UK to develop a vaccine against meningococcus A, and companies did not find the African market alone attractive enough to justify a separate development. Thanks to the dedication of motivated people at WHO, the development of a vaccine for meningococcus A remained on the agenda though, and after many years it has become a priority of the research and development task force of GAVI (Global Alliance for Vaccines and Immunization). This development increased awareness of the problem of meningococcus A in Africa, and shortly after US$70 million were awarded by the Bill and Melinda Gates Foundation to support the Meningitis Vaccine Project (MVP), aimed at eliminating meningococcal epidemics in sub-Saharan Africa. Discussions began between the members of the MVP and vaccine manufacturers that ended up with the solution described by Jodar and colleagues, which proposes a project, now in preclinical studies, aimed at the development of a conjugate vaccine against meningococcus A for a price lower than $0.5 per dose. The question is, might alternative solutions have sped up the development process? Jodar and co-workers argue that established vaccine manufacturers, who had projects in clinical trials, had no interest in the project mostly because of the opportunity costs involved. I agree that no vaccine manufacturer would be interested in a vaccine with a unit price lower than $1. However, I am confident that despite the opportunity costs some industrialised vaccine manufacturers, who have vaccines that contain the conjugate meningococcus A and strain W135 in phase 2 trials, would be willing to make the vaccine available at a price of $2–3 per dose. If so, such vaccines would reach Africa faster than the cheaper vaccine—in my experience, a vaccine in preclinical studies is 3–8 years behind a vaccine in phase 2 clinical trials—and could have included W135, which is a major concern in Africa. I believe that by trying to reduce the cost to a minimum, the vaccine's development has been delayed by 3–8 years, which seems a high price to pay. R Rappuoli is head of vaccines research at Chiron Corporation. The real cost of an affordable vaccine for meningococcus AAuthors' reply Full-Text PDF