You have read correctly, Restaurants, Bars, and Museums no longer accept the CDC card as of Nov. 1, 2021. You need to get what they are referring to as a Belgian CST. The information is available here: https://coronavirus.brussels/en/belgian-cst-for-foreigners/
This process works in conjunction with the Belgian CovidSafe app, you will need to download that onto your smartphone.
You will then follow the link above to find the form to fill out. Several "helps":
- You will be asked in several drop down lists about the vaccine you received. I had the Pfizer for example, but in the first drop down, that does not appear, however Comirnaty is, which is the name of the Pfizer vaccine, the next drop down will then show Pfizer. Point being, you may need to have more information about the vaccine you received in order to properly fill out the form.
- One question asks if your official record has a "watermark" on it, say "Yes", the CDC logo is the watermark.
- Finally, you need to take pictures of your passport photo page and your CDC card to submit with the form. Use a lower resolution setting on your camera, if the file size is too large, it will not submit.
Once you fill out the form and submit, you should receive a response in 1 business day, we received them in about 20 minutes to an hour. The response will have a code, this is put into the Covidsafe app, and a QR code will be generated.
The QR code is only valid in Belgium, and only for 30 days.
As for testing, the rapid tests may be wise, but you will have to figure out the Belgian test system. They expect you will test on Day 2 and Day 7. There are relatively few test centers, and tests cost about 50 euro each. Some Pharmacies do offer rapid Antigen tests, not sure the cost. If you go the "bring your own" route, make sure you download all needed apps in the US and understand how to call in and conduct the test.