You now can benefit from the 99.999% DynamoDB availability SLA more easily by adding global tables replicas to your existing, single-region tables with a few clicks in the DynamoDB console. Previously, you could only create new DynamoDB global tables. For existing tables, you can now easily create a hot standby for disaster recovery, or you can extend your existing tables to additional AWS Regions to support latency-sensitive applications, without taking any downtime on your table. In addition, you benefit from efficiency improvements that can reduce replicated writes consumed by up to 50 percent.
from Recent Announcements: https://aws.amazon.com/about-aws/whats-new/2019/11/you-can-now-enhance-availability-of-your-existing-amazon-dynamodb-tables-by-adding-global-replicas/