Download Full PDF – EARLY VACCINE BENEFITS – PhageVax Named
- As noted in the recent Centers for Disease Control and Prevention community planning guidance1, the only intervention that can reasonably be expected to control an influenza pandemic is vaccination of a large fraction of the population with a strain-matched vaccine. Planners and modelers commonly assume that such a vaccine intervention would be similar to recent vaccination interventions for seasonal influenza, employing egg-based vaccine production technology. Thus analyses assume that pandemic influenza vaccine will not be available until four to six months after the onset of the pandemic, and that vaccine could not be produced faster than 4 million doses per week (corresponding to 100 million doses in 6 months). Under this view, several recent studies2-5 have analyzed how various non-vaccine interventions might be able to control an influenza pandemic until vaccine can be delivered. Other studies6 do not incorporate vaccination production and delivery because of the assumption that it would be too late.
- Alternative approaches to egg-based vaccine production would grow virus in bioreactors using mammalian cell cultures, insect cell cultures (e.g. NovaVax, Inc. and Protein Sciences, Inc.), or bacteria (e.g. PhageVax, Inc.). These technology developments might reduce the lag time between identification of the influenza strain and initial vaccine production capability, and might also allow higher US production rates. This analysis considers the potential of these new technologies to mitigate a pandemic.
- The effectiveness of a vaccine intervention to control an influenza pandemic will depend on 1) when the vaccine will first become available, 2) how many people can be treated per week once vaccination starts, 3) how effective the vaccine is, and 4) how many days following inoculation are required for immunity to build up. In addition, the impact of a vaccine intervention on the pandemic will depend on other interventions that are used in conjunction. This analysis compares the impact of vaccine distribution starting four months earlier than the seasonal influenza experience, comparing the impact of a range of vaccine production rates. It also compares the case of a two-dose course with a one-dose requirement. Most significantly, it examines the impact of early vaccine intervention used in conjunction with antiviral medication.
- If a vaccine can be produced four months earlier relative to egg-based seasonal influenza vaccine production, at a production rate sufficient to vaccinate 95% of the population within a one-month period, the impact on the pandemic would be enormous. In the absence of any other intervention, such a vaccine would reduce the mortality rate by a factor of five (from 614 deaths per 100,000 persons to 121 deaths per 100,000). Furthermore, if the existing strategic national stockpile (SNS) of 20 million courses of antiviral medication is used in conjunction with the vaccine intervention (for therapeutic treatment of diagnosed cases and prophylactic treatment of household members of diagnosed cases), the additional use of the early, rapidly produced vaccine would reduce the mortality from 550 per 100,000 to only 3 per 100,000, well below the mortality rate of seasonal influenza.
Read The Full Document with Graphical Data – Download