add a comment |. up vote 1 down vote. If a game has a value, it need not to have a mixed strategy Nash equilibrium. In the Von Neumann's Minimax theorem stated above, it is assumed that, for each player, the set of mixed strategy best responses is nonempty given the other player's mixed strategy.
Not all RNA viruses are retroviruses, e.g., the measles virus and flu virus are RNA viruses, but not retroviruses. There are three families of retroviruses: oncoviruses (causing cancer), lentiviruses (slow viruses, of which HIV is one), and foamy viruses or spumaviruses (about which much less is known).
Other enteroviruses belonging to Picornaviridae include poliovirus and Coxsackie A virus. Rhinovirus is one of the smallest types of virus, with a diameter of around 30 nanometers. Most other viruses such as vaccinia or smallpox are around ten times this size, with diameters of about 300 nanometers.