In this case, the usual rules for payment of wages with sickness apply. That does not change for the corona virus. If you are sick, article 53 of the ABU-CAO applies. If you have an employment contract phase A with agency clause, and you get sick, the assignment and therefore the agency work employment contract will be ended. You will be signed off sick with the UWV and you will receive a ZW-payment.
If you have a contract without agency clause, the payment will be continued for the duration of the contract in case you are sick: the first year 90%, the second year 80% of the salary.