SeriesLow-efficacy HIV vaccines: potential for community-based intervention programmes
Section snippets
Vaccination and the individual
Parameters for evaluating vaccine efficacy must be defined precisely to facilitate measurement and evaluation in phase III trials.8, 9, 10 Mathematical representation of the effect of vaccination on the individual helps in this process. The parameters shown in the panel are central to that analysis.
We therefore arrive at a minimum of eight parameters that must be measured to assess the impact of vaccination on the individual. Recent work on the measurement of impact by McLean and Blower11 made
Vaccination and the community
The manner in which different properties of the vaccine act to reduce the rate of spread of HIV-1 in a vaccinated population is most easily understood by reference to their impact on the basic reproductive number of infection, Ro, which defines the average number of secondary cases of infection generated by one primary case in a susceptible population.12 The magnitude of Ro is determined by parameters that describe the typical course of infection in an individual and those that determine
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Cited by (68)
The Impact of Vaccination on the Epidemiology of Infectious Diseases
2016, The Vaccine Book: Second EditionAnalyzing the dynamics of an SIRS vaccination model with waning natural and vaccine-induced immunity
2011, Nonlinear Analysis: Real World ApplicationsCitation Excerpt :One aspect of disease and vaccine that is very influential in the public health impact of vaccines is the duration of immunity. The duration of human immunity against infections with microparasites varies greatly, ranging from lifelong (such as that for viral infections) to almost non-existent (as in the case of some bacterial infections) [6]. Likewise, some vaccines confer immunity against infection that may be lifelong, whereas other vaccines seem to provide only temporary immunity against infection (e.g., vaccines for pertussis [7] and varicella [8]).
Higher variability in the number of sexual partners in males can contribute to a higher prevalence of sexually transmitted diseases in females
2009, Journal of Theoretical BiologyCitation Excerpt :Using a relatively simple agent-based, stochastic model we have shown that if men do have a wider sex partner distribution than women, then this in itself can lead to differences in the gender equilibrium prevalences. This has apparently not been noted or investigated before: while there exists an extensive literature on modelling STD epidemics (Anderson and May, 1988; Anderson and Garnett, 1996, 2000; Kretzschmar et al., 1996; Morris and Kretzschmar, 1997; Korenromp et al., 2000; Stover et al., 2002; Grassly and Garnett, 2005) only a few models account for differences in the shape or variance of the distribution of sexual contacts (Anderson and May, 1991; Garnett and Anderson, 1993, 1994; Thrall et al., 2000), and none of these analyses have explicitly commented upon the fact that the variance in males is higher than in females and investigated whether this could in itself be a causative factor for different gender prevalences. Perhaps part of the reason for this discrepancy has to do with modelling approach: the stochastic, agent-based approach employed here is directly aimed at situations where individual variability is important and makes it very easy to include age and sex partner structure in the population.
Potential population health outcomes and expenditures of HIV vaccination strategies in the United States
2009, VaccineCitation Excerpt :If the potential health and economic benefits of a vaccine are large, then relatively large public investments in research may be warranted. Prior analyses (e.g. [12–36]) have evaluated the effect of vaccines in different settings, but no studies have comprehensively evaluated the potential population health benefits and costs across all risk groups in the United States. To inform this debate, we evaluated the potential population health benefits and expenditures of alternative HIV vaccination strategies in the United States.
Modelling effects of public health educational campaigns on HIV/AIDS transmission dynamics
2009, Applied Mathematical Modelling