Capsid and RNA stabilisation of the oral polio vaccine

The oral polio vaccine is the least stable vaccine of the common childhood vaccines. Two different inactivation mechanisms are responsible fur the the rmolability of the vaccine, i.e. denaturation of the viral capsid and degra dation of the viral RNA within the capsid. Pirodavir, a capsid-binding comp ound, inhibits the viral capsid thermodenaturation. In this paper we show t hat deuterium oxide is able to stabilise the viral RNA against thermodegrad ation and that a combination of pirodavir and deuterium oxide leads to an a dditive effect indicating that both stabilisers work indeed on different in activation mechanisms. Furthermore, it is shown that the variation in therm ostability of the different vaccine strains is due to the different thermos tability of their capsids. (C) 2001 Elsevier Science Ltd. All rights reserv ed.