Epidemiology, mathematical modelling and economics of Streptococcus pneumoniae : assessing the potential impact of vaccination

Doctoral thesis English OPEN
Melegaro, Alessia
  • Subject: QR | RA0421

This thesis explores aspects of Streptococcus pneumoniae (pneumococcus) epidemiology and control, in view of the possible widespread introduction of conjugate vaccines in England and Wales.\ud \ud A review and analysis of a range of different epidemiological data sources showed that the burden of pneumococcal disease in England and Wales is high and remains mostly a condition of the very young and the elderly. A meta-analysis demonstrated the effectiveness of the polysaccharide vaccine against invasive pneumococcal disease among healthy elderly, to whom vaccination was not recommended at the start of this work. Using this result, a costeffectiveness analysis assessed the economic acceptability of such a programme, from the public health perspective.\ud \ud A better understanding of pneumococcal carriage and transmission is required to assess the effectiveness and cost-effectiveness of mass vaccination strategies with the pneumococcal conjugate vaccine. A novel model framework was developed and fitted to a longitudinal dataset of carriage in UK families. The results demonstrated an inverse relationship between duration of carriage and age and highlighted the importance of both family size and composition for persistence in a household. Great dissimilarities were estimated among the specific serotypes in terms of transmissibility, duration of carriage and level of competition. Realistic age structured dynamic models were developed and used to investigate the impact of a range of vaccine strategies. The importance of serotype replacement, as a consequence of vaccination, was demonstrated. The economic acceptability of alternative interventions with the conjugate vaccine depended on the magnitude of its indirect effects. Herd immunity had a considerable impact on the overall cost-effectiveness of the programmes since it may substantially reduce the burden of disease in older age groups. However, serotype replacement may counterbalance this reduction and lead to a non cost-effective result.
  • References (26)
    26 references, page 1 of 3

    [1] Bedford H, de Louvois J, Halket S, Peckham C, Hurley R, Harvey D. Meningitis in infancy in England and Wales: follow up at age 5 years. BMJ 2001;323:1-5.

    [2] Laurichesse H, Grimaud 0, Waight P, Johnson AP, George R, Miller E. Pneumococcal bacteremia and meningitis in England and Wales, 1993 to 1995. Commun Dis Public Health 1998;1:22-7.

    [3] Lim WS, Macfarlane IT, Boswell TC, Harrison TO, Rose D, Leinonen M, et al, Study of community acquired pneumonia aetiology (SCAPA) in adults admitted to hospital: implications for management guidelines. Thorax 2001;56:296-301.

    [4] McIntosh EDG, Booy R. Invasive pneumococcal disease in England and Wales: what is the true burden and what is the potential for prevention using 7 valent pneumococcal conjugate vaccine? Arch Dis Child 2002;86:403-6.

    [5] Salisbury DM, Begg NT, Immunisation against infectious disease. In: The Green Book (Chap. 25), 1996. http://www.dh.gov.uk.

    [6] Black SB, Shinefield HR, Fireman B, Lewis E, Ray P, Hansen JR, et al. Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Pediatr Infect Dis J 2000;19:187-95.

    [7] Black SB, Shinefield HR, Ling S, Hansen J, Fireman B, Spring D, et al. Effectiveness of heptavalent pneumococcal conjugate vaccine in children younger than five years of age for prevention of pneumonia. Pediatr Infect Dis J 2002;21:810-5.

    [8] Fireman B, Black SB, Shinefield HR, Lee J, Lewis E, Ray P. Impact of the pneumococcal conjugate vaccine on otitis media. Pediatr Infect Dis J 2003;22: 10-6. introduction of protein-polysaccharide conjugate vaccine. N Engl J Med 2003;348:1737-46.

    [29] Jacobs MR, Dagan R, Appelbaum PC, Burch DJ. Prevalence of antimicrobial-resistant pathogens in middle ear fluid: multinational study of 917 children with acute otitis media. Antimicrob Agents Chemother 1998;42:589-95.

    [30] Palmu AA, Herva E, Savolainen H, Karma P, Makela PH, Kilpi TM. Association of clinical signs and symptoms with bacterial findings in acute otitis media. Clin Infect Dis 2004;38:234-42.

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