Moderna COVID-19 Vaccine

Kathryn Dzintars, Pharm.D., BCPS


  • The Moderna COVID-19 vaccine (mRNA-1273) is a lipid nanoparticle-encapsulated, nucleoside-modified messenger RNA vaccine that encodes the SARS-CoV-2 spike glycoprotein.
    • Two-dose series, given one month (28 days) apart
  • The US FDA issued an Emergency for Use Authorization (EUA) to permit the emergency use of the Moderna COVID-19 vaccine for active immunization to prevent COVID-19 in individuals 18 years of age and older
    • Mandatory requirements for the administration of mRNA-1273 under the EUA are as follows:
      • The vaccine is authorized in patients ≥ 18 years of age.
      • The vaccination provider must give the individual receiving the Moderna COVID-19 vaccine or their caregiver the “Fact Sheet for Recipients and Caregivers” prior to the individual receiving Moderna COVID-19 vaccine.
      • Vaccine providers must include vaccine information to either the state’s or local jurisdiction’s Immunization Information System or other designated systems.
      • Vaccine providers are responsible for reporting certain events to the Vaccine Adverse Events Reporting System (VAERS):
        • Vaccine administration errors whether or not associated with an adverse event
        • Serious adverse events including death, life-threatening adverse events, inpatient hospitalization/prolonged hospitalization, persistent or significant incapacity, congenital anomaly/birth defects
        • Cases of the multisystem inflammatory syndrome (MIS) in children and adults
        • Cases of COVID-19 that result in hospitalization and death
      • Vaccine providers are responsible for responding to FDA requests for information about vaccine administration errors, adverse events, cases of MIS in adults and children, and cases of COVID-19 that result in hospitalization or death following administration of the Moderna or Pfizer-BioNTech COVID-19 Vaccine to recipients.
  • There are no data on the interchangeability of COVID-19 vaccines. If the series is initiated with the Moderna product, it should be completed with the Moderna product.



  • On December 19, 2020, ACIP voted in favor of the interim recommendation for use of the Moderna COVID-19 vaccine for individuals ≥ 18 years of age.
  • The EUA fact sheet for recipients and caregivers should be provided to vaccine recipients, and recipients should be counseled on local and systemic reactions.


Brand Name








SARS-Cov-2 S-protein encoded mRNA + lipid nanoparticle vaccine




0.5 mL IM on Day 0 and Day 28





  • This is a series of two vaccines given 1 month apart. The first dose (0.5 mL) should be given on Day 0 and the second dose (0.5 mL) on Day 28.
  • There are no data on the interchangeability of the COVID-19 vaccines.
    • If you receive the Moderna vaccine on Day 0, the series should be completed with the Moderna product.
  • Storage and stability information
    • Store in the original container to protect from light.
    • Vials should be stored frozen (-25° to -15°C); do NOT store on dry ice or below -40°C.
    • Vials can be stored refrigerated (2° to 8°C) for up to 30 days prior to first use.
    • Unpunctured vials may be stored between 8° to 25°C for up to 12 hours.
    • Once thawed, vials should NOT be refrozen.
  • After the first dose has been drawn, the vial should remain at room temperature and should be discarded after 6 hours if unused




  • This EUA is only valid for patients ≥ 18 years of age.

Pediatric BOOSTER




  • Overall, the Moderna vaccine is well-tolerated without serious adverse events reported to the FDA in the preliminary phase 3 trial information.
  • The incidence of adverse events is higher with the administration of the second dose of the vaccine.


  • Pain, redness, and swelling at the injection site.
  • Fever
  • Fatigue
  • Headache
  • Chills
  • Diarrhea
  • Muscle and joint pain


  • No vaccine/drug interactions have been identified at this time.


  • Do not administer Moderna COVID-19 vaccine to individuals with a known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the Moderna COVID-19 vaccine.


  • The highest neutralization titers were obtained at day 29 and day 57, confirming the need for two-dose series.
    • Dose #2 elicited a robust immune response.
    • Serum neutralizing activity was detected by two methods (binding antibody and neutralizing responses) in all 45 participants after the second dose in a phase 1 trial[3].
  • The complete immune response is still being elucidated.


An ongoing, placebo-controlled, observer-blinded safety and efficacy trial in individuals ≥ 18 years of age is being conducted in the US.

  • 30,420 participants were randomized 1:1 to receive 2 doses, 28 days apart, of either placebo or the mRNA-1273 vaccine.
    • Follow-up for efficacy and safety will continue for 24 months after the second dose of the vaccine.
  • The primary endpoints were vaccine efficacy against COVID-19, safety and immunogenicity.
  • The per-protocol set included 28,208 patients who received injections (14,134 in the vaccine group; 14,073 in the placebo group).
  • There were 11 cases of COVID-19 disease onset at least 7 days after the second dose in those receiving active vaccine compared to 185 cases of COVID-19 disease in those patients assigned placebo.
    • This translates to 94.1% vaccine efficacy in preventing COVID-19 disease.
  • Similar vaccine efficacy was noted among subgroups, including age, sex, race, ethnicity and baseline body mass index.
  • The most common adverse effects were injection site pain, fatigue and headache.
  • The overall incidence of adverse effects was low, and similar between the vaccine and placebo groups. Adverse effects were enhanced with the second dose.


  • It is MANDATORY for vaccination providers to report to the Vaccine Adverse Event Reporting System (VAERS) all vaccine administration errors, all serious adverse events, cases of multisystem inflammatory syndrome (MIS) in adults and children, and hospitalized or fatal cases of COVID-19 following vaccination with the Moderna COVID-19 vaccine.

Basis for recommendation

  1. Fact Sheet for Healthcare providers administering the vaccine, EUA for the Moderna COVID-19 Vaccine to prevent COVID-19. (Accessed December 21, 2020.)

    Fact Sheet for Providers administering vaccine: Emergency Use Authorization (EUA) of the Moderna COVID-19 Vaccine to Prevent Coronavirus Disease 2019. Preliminary Phase 3 clinical trial data is included here pending publication of additional trial data.

  2. Oliver S, Gargano J, Marin M, et al. The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Moderna COVID-19 Vaccine — United States, December 2020. MMWR Morb Mortal Wkly Rep. ePub: 20 December 2020. DOI:


    MMWR report providing ACIP interim recommendations endorsing the Moderna EUA from the FDA. The committee agreed that robust clinical trial data support the administration of the two-dose vaccine series on Day 0 and Day 28 for the prevention of COVID-19 disease in those 18 years of age and older.


  1. Jackson LA, Anderson EJ, Rouphael NG, et al. An mRNA Vaccine against SARS-CoV-2 - Preliminary Report. N Engl J Med. 2020;383(20):1920-1931.  [PMID:32663912]

    Comment: This is the Phase 1, dose-escalation, open-label trial that included 45 adult participants, age 18 - 55, who received 2 doses of the mRNA-1273 vaccine, 28 days apart. Vaccine doses were 25 mcg, 100 mcg or 250 mcg. Higher doses elicited higher antibody responses. Serum neutralizing activity was detected in all participants after two vaccinations. The most common adverse events included fatigue, chills, headache, myalgias and pain at the injection site. Adverse events were higher with the second dose.

Moderna COVID-19 Vaccine is a sample topic from the Johns Hopkins ABX Guide.

To view other topics, please or .

Official website of the Johns Hopkins Antibiotic (ABX), HIV, Diabetes, and Psychiatry Guides, powered by Unbound Medicine. Johns Hopkins Guide App for iOS, iPhone, iPad, and Android included. .

Last updated: December 23, 2020