Panel 6. The adenovirus (highly magnified in the top left, see also panels 3 to 5) can help smaller viruses to replicate. These viruses are called AAVs (for Adeno-Associated Virus, highly magnifi ed in the top right). AAVs are tiny viruses (1/80000th of a millimeter) that infect humans and non-human primates. They form small icosahedrons, consisting of only 60 protein subunits (the capsomers). They are very common in humans and are not attributed to any pathology. They induce a weak immune response and are therefore unnoticed during an infection.