Do you need to worry about a super virus.

The answer is, NO. One reason is that if a super virus could take over all life forms then it would have, and since no virus has taken over then it can not do so. That reason, however, does not explain why a virus can not take over. This link may go further: http://arxiv.org/abs/1001.3101. The paper I think is a further characterization the emergence of the forced cooperation strategy.