{"data":{"id":"us/21-cfr-866.3900","jurisdiction":"us","citation":"21 CFR 866.3900","heading":"Varicella-zoster virus serological reagents.","body":"(a) Identification. Varicella-zoster virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to varicella-zoster in serum. The identification aids in the diagnosis of diseases caused by varicella-zoster viruses and provides epidemiological information on these diseases. Varicella (chicken pox) is a mild, highly infectious disease, chiefly of children. Zoster (shingles) is the recurrent form of the disease, occurring in adults who were previously infected with varicella-zoster viruses. Zoster is the response (characterized by a rash) of the partially immune host to a reactivation of varicella viruses present in latent form in the patient's body.\n(b) Classification. Class II (performance standards).","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER H—MEDICAL DEVICES","PART 866—IMMUNOLOGY AND MICROBIOLOGY DEVICES","Subpart D—Serological Reagents"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"c4de84e5dd9a57aa87bf88b655657e4ce1e0e6f23b38d941739041f6ca469e53","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-866.3870","next":"us/21-cfr-866.3920"},"notice":"GroundRules: Original legal text. Not legal advice."}