Use of JYNNEOS (Smallpox and Monkeypox Vaccine, Live, Nonreplicating) for Preexposure Vaccination of Persons at Risk for Occupational Exposure to Orthopoxviruses

Recommendations of the Advisory Committee on Immunization Practices -- United States, 2022

Agam K. Rao, MD; Brett W. Petersen, MD; Florence Whitehill, DVM; Jafar H. Razeq, PhD; Stuart N. Isaacs, MD; Michael J. Merchlinsky, PhD; Doug Campos-Outcalt, MD; Rebecca L. Morgan, PhD; Inger Damon, MD, PhD; Pablo J. Sánchez, MD; Beth P. Bell, MD


Morbidity and Mortality Weekly Report. 2022;71(22):734-742. 

In This Article

Future Research

Additional data on JYNNEOS vaccine are needed. Further studies are needed to determine the duration of protection after the 2-dose JYNNEOS vaccination series; recommendations regarding the frequency of booster doses can be modified accordingly. The effectiveness of a single dose JYNNEOS series should be evaluated if orthopoxvirus exposures occur before peak immunogenicity is achieved. Clinical trials evaluating the risk for myopericarditis and serious adverse events are needed to ensure that the risks are characterized and guidance about co-administration of JYNNEOS with mRNA COVID-19 vaccines can be elucidated. Establishing a correlate of protection after vaccination with JYNNEOS might facilitate confirmation of effective vaccination in certain populations and might also shed light on the effectiveness of a single dose of JYNNEOS vaccine. In addition, extensive studies to date have not identified the specific small mammal reservoir for some orthopoxviruses (e.g., Monkeypox virus); identifying the specific reservoir might facilitate the identification of high-risk activities for acquiring orthopoxvirus infections that are not already recognized.