The Ankara strain was taken to West Germany in 1953, where Herrlich and Mayr grew it on chorioallantoic membrane at the University of Munich. After 572 serial passages, the vaccinia virus had lost over 14% of its genome and could no longer replicate in human cells. MVA was used in West Germany in 1977–1980, but the eradication of smallpox ended the vaccination campaign after only 120,000 doses.MVA stimulates the production of fewer antibodies than replicating vaccines. During the smallpox eradication campaign, MVA was considered to be a pre-vaccine that would be administered before a replicating vaccine to reduce the side effects, or an alternative vaccine that could be safely given to people at high risk from a replicating vaccine. : 585  Japan evaluated MVA and rejected it due to its low immunogenicity, deciding to develop its own attenuated vaccine instead. In the 2000s, MVA was tested in animal models at much higher dosages. When MVA is given to monkeys at 40 times the dosage of Dryvax, it stimulates a more rapid immune response while still causing lesser side effects. MVA-BN (also known as: Imvanex in the European Union; Imvamune in Canada; and Jynneos) is a vaccine manufactured by Bavarian Nordic by growing MVA in cell culture. Unlike replicating vaccines, MVA-BN is administered by injection via the subcutaneous route and does not result in a vaccine "take." It is safer for immunocompromised patients and those who are at risk from a vaccinia infection. MVA-BN has been approved in the European Union, Canada, and the United States.
Potency
Comparing its analgesia-sedation effect in ventilated patients, remifentanil may be superior to morphine but not to fentanyl. Circumventing naltrexone
Remifentanil has been used with some success to circumvent naltrexone in patients who are in need of pain management. Abuse potential
Remifentanil, being a μ-receptor agonist, functions like other μ-receptor agonists, such as morphine and codeine; it can cause euphoria and has the potential for abuse. However, due to its rapid metabolism and short-acting half-life the likelihood of abuse is quite low. Nevertheless, there have been some documentations of remifentanil abuse. Development and marketing
Prior to the development of remifentanil, most short-acting hypnotics and amnestics faced issues with prolonged use, where accumulation would result in unfavorable lingering effects during post-operative recovery. Remifentanil was designed to serve as a strong anesthetic with an ultra-short and predictable duration that would not have accumulation issues.Remifentanil was patented by Glaxo Wellcome Inc. and was FDA approved on July 12, 1996. Its patent ended on the 10th of September 2017. Pricing for Ultiva
1 mg vial - US$30.19
2 mg vial - US$57.20
5 mg vial - US$118.15

Regulation
In Hong Kong, remifentanil is regulated under Schedule 1 of Hong Kongs Chapter 134 Dangerous Drugs Ordinance. It can only be used legally by health professionals and for university research purposes. The substance can be given by pharmacists under a prescription. Anyone who supplies the substance without prescription can be fined $10000 (HKD). The penalty for trafficking or manufacturing the substance is a $5,000,000 (HKD) fine and life imprisonment.