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Vaccination, which provides effective, safe infectious disease protection, is among the most important recent public health and immunological achievements. However, infectious disease remains the leading cause of death in developing countries because several vaccines require repeated administrations and children are often incompletely immunized. Microsphere-based systems, providing controlled release delivery, can obviate the need for repeat immunizations. Here, we review the function of sustained and pulsatile release of biodegradable polymeric microspheres in parenteral and mucosal single-dose vaccine administration. We also review the active-targeting function of polymeric particles. With their shield and co-delivery functions, polymeric particles are applied to develop single-dose and mucosally administered vaccines as well as to improve subunit vaccines. Because polymeric particles are easily surface-modified, they have been recently used in vaccine development for cancers and many infectious diseases without effective vaccines (e.g., human immunodeficiency virus infection). These polymeric particle functions yield important vaccine carriers and multiple benefits.

Since 1998, Taiwan has experienced annual outbreaks of enterovirus 71 (EV71) nationwide. The area around Taichung City experienced a particularly large outbreak in 2005, after which EV71 disappeared for 2 y before re-emerging in 2008. Here we present the clinical, genotypic, and epidemiological baseline data for the 2005 Taichung outbreak.Throat swab, stool and cerebrospinal fluid samples were collected and stored in viral transport medium. Samples were tested by reverse-transcriptase polymerase chain reaction and viral culture. Epidemiological, laboratory, and clinical data were extracted from medical record reviews. A total of 27 virus isolates were selected for phylogenetic analysis.Confirmed phylogenetic results of the viruses were separated into 5 groups. The 5'-UTR regions served as a focus for investigating genetic relationships among the 27 EV71 isolates, all of which belonged to a distinct clade in the C4 genotype. Most of the strains belonged to 5 observed epidemic groups.In conclusion, the 2005 outbreak in central Taiwan was caused by divergent EV71 strains belonging to the C4 genotype.

The Bacille Calmette-Guerin (BCG) vaccine is a live attenuated vaccine prepared from a strain of Mycobacterium bovis. The potency of this vaccine is dependent on the amount of viable cells. The conventional method to determine the potency of the BCG vaccine is to measure the number of colony forming units (CFU) produced after the vaccine has been reconstituted in normal saline and the cells cultured on Lowenstein-Jensen (LJ) medium. However, as M. bovis is a slow growing organism, it needs to grow at least four weeks to be detected in the potency assay. The results of the potency assay could also vary due to manual counting. Therefore, in order to increase the assay efficiency and decrease the variation of the results, we developed an alternative method by using flow cytometer combined with cell counter (viable counts calculated from flow cytometer and counter, VFC) to determine the potency of BCG vaccines. To further test the accuracy of the assay we developed, the viable counts of ten batches of...