What happened to the containment for the virus in the US? How was the virus even contained?

From the text (containment):

"Some of Nurse Mayinga's blood had ended up in the United States, and the strain of virus that had once lived in Nurse Mayinga's blood now lived in small glass vials kept in superfreezers at the Institute, which were maintained at minus one hundred and sixty degrees Fahrenheit. The freezers were fitted with padlocks and alarms and were plastered with biohazard flowers and sealed with bands of sticky tape, because it seals cracks. It could be said that without sticky tape there would be no such thing as biocontainment."

The containment of the virus was breached when Gene Johnson thawed some of Nurse Mayinga's blood and injected it into laboratory monkeys.

Source(s): The Hot Zone