COVID-19 bivalent vaccine, mRNA-Moderna (Investigational)

Brand and Other Names:mRNA-1273.222
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Dosing & Uses


Dosage Forms & Strengths

injection, suspension

  • 50mcg/0.5mL (multiple dose 2.5mL vial)
  • Each 0.5mL contains 25 mcg of original (wild-type spike protein) plus 25 mcg of omicron BA.4/BA.5 subvariants spike protein

COVID-19 Disease Prevention

Emergency use authorization granted August 31, 2022

Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine is indicated as a single booster dose

0.5 mL IM as a single booster dose

Administer at least 2 months after either

  • Completion of primary vaccination with any authorized or approved monovalent COVID-19 vaccine, OR
  • Receipt of the most recent booster dose with any authorized or approved monovalent COVID-19 vaccine

Dosing Considerations

Limitation of effectiveness: May not protect all vaccine recipients

<18 years: Safety and efficacy not established

<18 years: Safety and efficacy not established


Adverse Effects

VAERS Reporting

Mandatory for vaccination providers to report to the vaccine adverse events reporting system (VAERS) all vaccine administration errors, serious adverse events, multisystem inflammatory syndrome, and hospitalized or fatal cases of COVID-19 following vaccination


18-64 years

  • Pain (87.8%)
  • Fatigue (58.6%)
  • Headache (49%)
  • Myalgia (43%)
  • Use of antipyretic/pain medication (39.5%)
  • Arthralgia (33.1%)
  • Chills (24.3%)
  • Axillary swelling/tenderness (21.3%)
  • Nausea/vomiting (13.3%)

≥65 years

  • Pain (61.5%)
  • Fatigue (49.4%)
  • Headache (36.2%)
  • Myalgia (34.5%)
  • Arthralgia (28.2%)
  • Use of antipyretic/pain medication (26.4%)
  • Chills (23%)
  • Axillary swelling/tenderness (11.5%)


18-64 years

  • Swelling ≥25 mm (8.4%)
  • Erythema ≥25 mm (7.6%)
  • Fatigue, grade 3 (3.8%)
  • Fever (3.8%)
  • Myalgias, grade 3 (3.4%)
  • Erythema, grade 3 (2.7%)
  • Swelling, grade 3 (1.5%)
  • Headache, grade 3 (1.5%)
  • Arthralgia, grade 3 (1.1%)

≥65 years

  • Erythema ≥25 mm (5.7%)
  • Nausea/vomiting (4.7%)
  • Swelling ≥25 mm (4.6%)
  • Fever (4.2%)
  • Fatigue, grade 3 (2.9%)
  • Pain, grade 3 (1.1%)
  • Erythema, grade 3 (1.1%)


18-64 years

  • Pain, grade 3 (0.8%)
  • Chills, grade 3 (0.4%)
  • Fever, grade 3 (0.4%)

≥65 years

  • Axillary swelling/tenderness, grade 3 (0.6%)
  • Swelling, Grade 3 (0.6%)
  • Myalgia, grade 3 (0.6%)
  • Headache, grade 3 (0.6%)
  • Nausea/vomiting, grade 3 (0.6%)



Known history of severe allergic reaction (eg, anaphylaxis) to any component in vaccine


Appropriate treatment used to manage immediate allergic reactions must be immediately available if an acute anaphylactic reaction occurs following administration

Syncope (fainting) may occur; procedures should be in place to avoid injury from fainting

Immunocompromised persons, including individuals receiving immunosuppressant therapy, may have a diminished immune response

May not protect all vaccine recipients

Myocarditis and pericarditis

  • May increase risks of myocarditis and pericarditis, particularly within 7 days following the second dose.
  • Risk is higher among adolescent and adult males aged <40 years than among females and older males, and the observed risk is highest in males aged 18-24 years
  • Available data suggest that majority of symptoms resolved with conservative management
  • The CDC has published clinical considerations relevant to myocarditis and pericarditis with mRNA COVID-19 vaccines

Pregnancy & Lactation


A growing body of evidence on the safety and effectiveness of COVID-19 vaccination indicates that the benefits of vaccination outweigh any known or potential risks of COVID-19 vaccination during pregnancy

Recent studies have also shown that antibodies produced after COVID-19 vaccination during pregnancy are transferred to the newborn, and COVID-19 vaccination of people who are pregnant reduces the risk of COVID-19 hospitalization in infants younger than 6 months

CDC guidelines for vaccination of pregnant or lactating females

Pregnancy registry

  • Monitors pregnancy outcomes in women exposed to vaccine during pregnancy
  • Encourage females who are vaccinated during pregnancy to enroll in the registry


Unknown whether vaccine is excreted in human milk

Data are unavailable to assess the effects on breastfed infants or milk production/excretion

For preventive vaccines, underlying maternal condition is susceptibility to disease prevented by the vaccine

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.



Mechanism of Action

Nucleoside-modified messenger RNA (modRNA) encoding the viral spike (S) glycoprotein of SARS-CoV-2; formulated in lipid particles, which enable delivery of RNA into host cells to allow expression of the SARS-CoV-2 S antigen

Elicits an immune response to the S antigen, which protects against COVID-19



IM Preparation

Thaw vials

  • Refrigerator: Thaw for 2 hr; let each vial stand at room temperature for 15 minutes before administering
  • Room temperature: Thaw for 45 minutes
  • After thawing, do not refreeze

Inspect vial contents

  • Suspension should appear white to off-white
  • It may contain white or translucent product-related particulates
  • Do not administer if vaccine is discolored or contains other particulate matter

Prepare dose

  • Swirl vial gently after thawing and between each withdrawal
  • Do not shake
  • Do not dilute
  • If amount of vaccine remaining in vial cannot provide a full 0.5-mL dose, discard vial and contents; do not pool excess vaccine from multiple vials

IM Administration

For IM injection only

Monitor for immediate adverse reactions according to CDC guidelines


During storage, minimize exposure to room light, and avoid exposure to direct sunlight and ultraviolet light

Frozen storage

  • Freeze between -50 to -15ºC (-58 to 5ºF)

Storage after thawing

  • Do not refreeze once thawed
  • Discard vial 12 hr after first puncture
  • Record date and time of first use on vial label
  • Thawed vials can be handled in room light conditions
  • Storage at 2-8ºC (36-46ºF): Refrigerate for up to 30 days before first use
  • Storage at 8-25ºC (46-77ºF): Vials may be stored for up to 24 hr (total storage time at this temperature range)
  • Vial storage during use: Store at 2-25ºC (36-77ºF); record date and time of first use on vial label


  • If transport at -50 to -15ºC (-58 to 5ºF) is not feasible, may transport thawed vials for up to 12 hr at 2-8ºC (36-46ºF)
  • Do not refreeze, continue storage at 2-8ºC (36-46ºF) until use


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Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.