Understanding how immunity shapes the dynamics of multistrain pathogens is essential in determining the selective pressures imposed by vaccines. The replacement of vaccine-type strains by other strains for which vaccination offers little or no protection is a concern for numerous pathogens, including influenza, pneumococcus, and most recently rotavirus.
Measles epidemics in West Africa cause a significant proportion of vaccine-preventable childhood mortality. Epidemics are strongly seasonal, but the drivers of these fluctuations are poorly understood, which limits the predictability of outbreaks and the dynamic response to immunization. Researchers at Princeton University are developing an unconventional way to use satellite images of nighttime lights to monitor seasonal population migration patterns and potentially pinpointing disease hotspots in developing nations. “We did this study after it became clear that we absolutely needed to understand the reason for such strongly seasonal outbreaks,” said Nita Bharti, lead author of the article published in the December 9, 2011 issue of Science.
What is the Potential Impact of Adding the Rotavirus or Pneumococcal Vaccines to the Thailand Supply Chain?
Introducing one or more new vaccines could impact a country’s vaccine supply chain, the steps required to get a vaccine from manufacturer to patient. The effects could vary from country to country. As detailed in a recently published study in PLoS ONE, in collaboration with researchers from the Southern Vaccine Research Team (SVRT) at the Prince of Songkla University, Thailand, the Vaccine Modeling Initiative (VMI) researchers at the University of Pittsburgh developed a simulation model of the Trang Province, Thailand, vaccine supply chain.
Location-specific patterns of exposure to recent pre-pandemic strains of influenza A in southern China
Variation in influenza incidence between locations is commonly observed on large spatial scales. It is unclear whether such variation occurs on smaller spatial scales and whether it is the result of heterogeneities in population demographics or more subtle differences in population structure and connectivity. In the August 9th edition of Nature Communications, researchers from the Johns Hopkins Bloomberg School of Public Health, Hong Kong University, Guangzhou Hospital #12 and the University of Liverpool, including members of the Vaccine Modeling Initiative, show that significant differences in immunity to influenza A viruses among communities in China are not explained by differences in population demographics.
Study shows that combination of interventions targeting different stages of mosquito lifecycle can lead to a reduction in mosquito numbers
Intensive anti-malaria campaigns targeting the Anopheles population have demonstrated substantial reductions in adult mosquito density. Understanding the population dynamics of Anopheles mosquitoes throughout their whole lifecycle is important to assess the likely impact of vector control interventions alone and in combination as well as to aid the design of novel interventions.