Seminar
Miriam Nuno
Assessing Basic Control Measures, Antivirals and Vaccine in Curtailing Pandemic Influenza: Scenarios for the US, UK, and the Netherlands
Recurrent avian flu cases in humans, arising primarily from direct contact with poultry, in several regions of the world have prompted the urgency to develop pandemic preparedness plans worldwide. Leading recommendations in these plans include basic public health control measures for minimizing transmission in hospitals and communities, the use of antiviral drugs, and vaccination. This paper presents a mathematical model for the evaluation of the pandemic flu preparedness plans of the United States (US), the United Kingdom (UK) and the Netherlands. The model is used to assess single and combined interventions. Using data from the US, we show that hospital and community transmission control measures alone can be highly effective in reducing the impact of a potential flu pandemic. We further show that while the singular use of antivirals could lead to very significant reductions in the burden of a pandemic, the combination of transmission control measures, antivirals and vaccine gives the most ``optimal'' result. However, implementing such an optimal strategy at the onset of a pandemic may not be realistic. Thus, it is important to consider other plausible alternatives. An optimal preparedness plan is largely dependent on the availability of resources; and, hence, it is country--specific. We show that for antiviral interventions, countries with limited supplies should emphasize their use therapeutically (rather than prophylactically). However, countries with large antiviral supplies can achieve greater reductions in disease burden by implementing them both prophylactically and therapeutically. This study promotes alternative strategies that may be feasible and attainable for the US, UK and the Netherlands. It emphasizes the importance of hospital and community transmission control measures in addition to the timely use of antiviral treatment in reducing the burden of a potential flu pandemic. The latter is consistent with the preparedness plans of the UK and the Netherlands. Our results indicate that a single-intervention program based on the use of vaccination seems to have limited impact in comparison to that based on the use of antivirals.