Modified Vaccinia Ankara Bavarian Nordic (MVA BN)

Prevention of smallpox and mpox (monkeypox) disease in adults

FDA-approved for adults 18 years of age and older determined to be at high risk for smallpox or mpox infection, such as laboratory workers, healthcare workers, and people identified during outbreaks. (2)

Prevention of mpox (monkeypox) disease in people under 18 (Emergency Use Authorization only)

Available under an FDA Emergency Use Authorization (issued August 2022, still in effect) for people younger than 18 determined to be at high risk of mpox infection specifically — this is EUA-based, not full approval, and does not cover smallpox prevention in this age group. Use should be based on individual risk assessment and specialist guidance. (2)

Injection-site pain

Incidence: Very common — reported by about 84.9% of vaccine-naive adults in clinical trials

Injection-site redness (erythema)

Incidence: Very common — about 60.8%

Injection-site swelling

Incidence: Common — about 51.6%

Injection-site induration (firmness)

Incidence: Common — about 45.4%

Injection-site itching (pruritus)

Incidence: Common — about 43.1%

Muscle pain (myalgia)

Incidence: Common — about 42.8%

Headache

Incidence: Common — about 34.8%

Fatigue

Incidence: Common — about 30.4%

Chest pain, shortness of breath, or a fast/pounding heartbeat (possible myocarditis or pericarditis)

Fainting or feeling faint/light-headed after the injection

Signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat, hives)

Myocarditis and pericarditis (inflammation of the heart muscle or its lining) have been reported after JYNNEOS vaccination, identified during postmarketing use — serious

Symptoms: Myocarditis and pericarditis (inflammation of the heart muscle or its lining) have been reported after JYNNEOS vaccination, identified during postmarketing use. In clinical trials, about 1.3% of recipients had cardiac findings of special interest, mostly symptomless troponin elevations picked up on blood tests; 6 cases (0.08%) were judged likely related to the vaccine. Seek prompt medical attention for chest pain, shortness of breath, or a fast or pounding heartbeat after vaccination.

Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)

Fainting (syncope), sometimes with injury from a fall, has been reported after vaccination — serious

Symptoms: Fainting (syncope), sometimes with injury from a fall, has been reported after vaccination. Staying seated or lying down for a short period after the injection, with observation for light-headedness beforehand, can reduce this risk.

Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)

Not for use in individuals with a history of severe allergic reaction to vaccine components — serious

Symptoms: Not for use in individuals with a history of severe allergic reaction to vaccine components. Use caution in immunocompromised individuals. May not provide full protection until 2 weeks after the second dose. Report any severe or unusual side effects to your healthcare provider.

Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)

Contraindications recorded in the clinician database — serious

Symptoms: Contraindications recorded in the clinician database: Contraindications include a history of severe allergic reaction (anaphylaxis) to a previous dose or any component of the vaccine. Use with caution in individuals with immunodeficiency. Jynneos is preferred over replicating vaccines in patients with eczema or immunosuppression due to its safety profile.

Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)

Pregnancy

Animal reproduction and developmental toxicity studies did not show evidence of fetal harm. Data on use in pregnant women are insufficient to establish whether there is a vaccine-associated risk in humans. If you are pregnant or planning pregnancy, discuss your individual exposure risk and the benefits and risks of vaccination with your healthcare provider. (2)

Breastfeeding

It is not known whether JYNNEOS passes into human breast milk. The developmental and health benefits of breastfeeding should be weighed against the mother's need for vaccination and any potential risk to the breastfed infant; discuss with your healthcare provider. (2)

Children

Full FDA approval covers adults 18 years and older only. For people younger than 18, JYNNEOS is available only under an FDA Emergency Use Authorization (issued August 2022) for prevention of mpox specifically (not smallpox) in those at high risk, given by subcutaneous injection, based on individual risk assessment and specialist guidance. Routine use in children is not otherwise recommended. (2)

Renal_impairment

The FDA prescribing information for JYNNEOS does not include a renal- or hepatic-impairment dosing section — the "Use in Specific Populations" section covers pregnancy, lactation, and pediatric/geriatric use only. As with most vaccines, the 0.5 mL dose is fixed and not adjusted for kidney or liver function. No dose adjustment is specified; people with significant renal or hepatic impairment should still discuss vaccination timing and any additional precautions with their treating clinician, since impaired immune response can occur with some underlying conditions. (2)

Hepatic_impairment

The FDA prescribing information for JYNNEOS does not include a renal- or hepatic-impairment dosing section — the "Use in Specific Populations" section covers pregnancy, lactation, and pediatric/geriatric use only. As with most vaccines, the 0.5 mL dose is fixed and not adjusted for kidney or liver function. No dose adjustment is specified; people with significant renal or hepatic impairment should still discuss vaccination timing and any additional precautions with their treating clinician, since impaired immune response can occur with some underlying conditions. (2)