Schema Premium plugin has support for schema.org SpecialAnnouncement type that allows you to add schema markups to pages about a Special Announcements on your site.
The “SpecialAnnouncement” type provides for simple date-stamped textual updates, as well as markup to associate the announcement with a situation (such as the Coronavirus pandemic), and to indicate URLs for various kinds of update such a school closures, public transport closures, quarantine guidelines, travel bans, and information about getting tested.
Follow these steps to add the new markup type:
1- Create a new Schema markup
The very first step is to go to Schema > Types, and click on the Add New button.
2- Select schema.org Special Announcement
The next screen will open the quick schema.org creation wizard. Select the schema.org Special Announcement type from the drop down list.

When you are done selecting; Schema Premium will confirm the creation of the new schema.org type, and you will have the choice to go through next steps, which is configuring the schema.org type you’ve selected.

3- Configure schema.org SpecialAnnouncement
To complete setup, set Location Rules and Properties for this schema.org type to take effect and take care of all the needed technical optimization of pages about Special Announcements on your site.

3-B- Locations
Create a set of rules to determine the target of this schema.org type.
For example, you can enable this markup on a specific page or post, or you may have a custom post type for pages about Special Announcements that you would like to enable this type to work on.
3-C- Event Properties
Optionally; this section allows you to configure schema:SpecialAnnouncement properties.
4- Update Schema
Click on the Update button to update schema.org type.
5- Test Structured Data
Test your schema.org markup in Google’s Structured Data Testing Tool to make sure it’s valid. You can test your markup with a simple click.
Here is an article that explains how you can test your schema.