Vincent, Alan, Rich, and Dickson discuss bacteria that can utilize arsenic in place of phosphorus, the passing of Frank Fenner, polio outbreak in The Congo, solving criminal cases of HIV transmission, and classifying viruses by capsid structure.

Vincent, Alan, and Rich answer listener questions about lab procedures, prokaryotes, endogenous retroviruses, the iPad and teaching, prions, mimivirus, splitting water with viruses, and the polio outbreak in Tajikistan.

Vincent and Alan converse about making published science accessible to everyone, global eradication of poliomyelitis, and whether a plant virus can cause disease in humans.

Vincent, Alan, and Rich revisit circovirus contamination of Rotarix, then discuss poxvirus-like replication of mimivirus in the cell cytoplasm, and whether seasonal influenza immunization increases the risk of infection with the 2009 H1N1 pandemic virus.