You're pretty safe anyway unless society falls apart. There's an unwritten rule about viruses: they can spread easily, or be extremely deadly, but not both. If they're both, they kill off their hosts too quickly to spread. In the past, this rule was disrupted by bad hygiene. Now that we've discovered the connection, it's very unlikely this rule will be broken without a complete disintegration of the social order.
You're pretty safe anyway unless society falls apart. There's an unwritten rule about viruses: they can spread easily, or be extremely deadly, but not both. If they're both, they kill off their hosts too quickly to spread. In the past, this rule was disrupted by bad hygiene. Now that we've discovered the connection, it's very unlikely this rule will be broken without a complete disintegration of the social order.
If you make it too deadly and too virulent someone sneezes in Brazil and Madagascar closes their port before you manage to infect them.