There are some indications it is making a difference in Seattle:

The Seattle area, home of the first known coronavirus case in the United States and the place where the virus claimed 37 of its first 50 victims, is now seeing evidence that strict containment strategies, imposed in the earliest days of the outbreak, are beginning to pay off — at least for now.

Deaths are not rising as fast as they are in other states. Dramatic declines in street traffic show that people are staying home. Hospitals have so far not been overwhelmed. And preliminary statistical models provided to public officials in Washington State suggest that the spread of the virus has slowed in the Seattle area in recent days.

While each infected person was spreading the virus to an average of 2.7 other people earlier in March, that number appears to have dropped, with one projection suggesting that it was now down to 1.4.