Hi @patsing78, I don't think there is any clear cut test to diagnose RA. Here's some information I found on Mayo Clinic's site -- "How can a doctor tell if you have rheumatoid arthritis? -- Rheumatoid arthritis can be difficult to diagnose in its early stages because the early signs and symptoms mimic those of many other diseases. There is no one blood test or physical finding to confirm the diagnosis. During the physical exam, your doctor will check your joints for swelling, redness and warmth." --- Rheumatoid arthritis - Diagnosis and treatment: https://www.mayoclinic.org/diseases-conditions/rheumatoid-arthritis/diagnosis-treatment/drc-20353653

Here's some other information that speaks to the difficulty diagnosing RA.
-- 8 Diseases That Could Mimic Rheumatoid Arthritis — and Delay Your Diagnosis: https://creakyjoints.org/about-arthritis/rheumatoid-arthritis/ra-overview/rheumatoid-arthritis-misdiagnoses/

You mentioned needing to know as it relates to further COVID vaccine injections. Here's an article from Mayo Clinic that discusses vaccines and their importance for those with RA, including the COVID vaccines.
-- Rheumatoid arthritis: Protect your health with vaccines: https://www.mayoclinic.org/diseases-conditions/rheumatoid-arthritis/in-depth/rheumatoid-arthritis-vaccines/art-20096217

Have you started any treatment or medications for RA?