Route and antigen shape immunity to dmLT-adjuvanted vaccines to a greater extent than biochemical stress or formulation excipients.

A key aspect to vaccine efficacy is formulation stability. Biochemical evaluations provide information on optimal compositions or thermal stability but are routinely validated by ex vivo analysis and not efficacy in animal models. Here we assessed formulations identified to improve or reduce stability of the mucosal adjuvant dmLT being investigated in polio and enterotoxigenic E. coli (ETEC) clinical vaccines. We observed biochemical changes to dmLT protein with formulation or thermal stress, including aggregation or subunit dissociation or alternatively resistance against these changes with specific buffer compositions. However, upon injection or mucosal vaccination with ETEC fimbriae adhesin proteins or inactivated polio virus, experimental findings indicated immunization route and co-administered antigen impacted vaccine immunogenicity more so than dmLT formulation stability (or instability). These results indicate the importance of both biochemical and vaccine-derived immunity assessment in formulation optimization. In addition, these studies have implications for use of dmLT in clinical settings and for delivery in resource poor settings.

Hand, Foot and Mouth Disease in the Andaman Islands, India.

OBJECTIVE: To investigate an outbreak of Hand, foot and mouth disease (HFMD) in Andaman Islands during 2013. METHODS: Epidemiological, clinical data and samples were collected from HFMD patients who attended selected hospitals. Data were analyzed and samples were processed for detection of Enterovirus and further confirmed by sequencing. Serotype-specific molecular typing was also done to identify the etiological agent. RESULTS: Of the 246 suspected patients, most were affected in August 2013 (92/246, 37.4%). Fever (71.2%) associated with typical HFMD rashes (100%) were the most common presenting symptoms and rashes were mostly distributed on hands (100%), legs (92%), mouth (77%), and buttocks (52.8%). All cases were reported as mild and recovered completely without any complications. Enterovirus was detected in 63 cases (50.4%). CONCLUSION: HFMD was mild, mostly reported in children <60 months of age, and in boys. Coxsackie virus A16 was found to be the only etiological agent for this specific outbreak.

B1c genetic subtype of coxsackievirus A16 associated with hand, foot and mouth disease in Andaman Islands, India.

BACKGROUND: An outbreak of hand, foot and mouth disease (HFMD) occurred in the Andaman Islands in 2013. Therefore, we aimed to identify the aetiological agent and to explore its genetic characteristics. METHODS: Clinical specimens were subjected to virus isolation, further confirmed by sequencing the partial VP1/2A region of enterovirus, and analysed using MEGA 6 software with intra-serotype reference sequences. RESULTS: Coxsackievirus A16 (CV A16) was found to be the causative agent, closely grouped with B1c genetic clusters of CV A16. However, it has significant genetic distance (K2P=0.059%) with B1c sub-clusters. CONCLUSION: Extended research work should be carried out to better understand the emerging nature of CV A16 associated with HFMD in these islands.GenBank accession numbers: KU523376-KU523387.