Moderna COVID-19 Vaccine Questions
Below are answers to commonly asked clinical questions about Moderna COVID-19 Vaccine. Get answers to other frequently asked questions:
The minimum order size and increment for Moderna COVID-19 Vaccine is 10 multidose vials per order.
Moderna COVID-19 Vaccine is authorized and recommended for people 18 years of age and older.
All people for whom vaccination is indicated should receive 2 doses 28 days apart. Do not schedule vaccine recipients to receive the second dose earlier than the recommended interval.
Second doses of Moderna COVID-19 Vaccine administered up to 4 days before the recommended date (4-day grace period) are considered valid. This means that when reviewing records, a second dose of Moderna COVID-19 Vaccine administered 24 or more days after the first dose is considered valid.
You should schedule the second dose of Moderna COVID-19 Vaccine 28 days after the first dose (the recommended interval). Do not use the 4-day grace period when scheduling appointments. Appointments for a second dose should be scheduled to meet the recommended interval.
If a dose is inadvertently administered before the 4-day grace period, it does not need to be repeated. This means that when reviewing records, a second dose of Moderna COVID-19 Vaccine administered 23 or less days after the first dose does not need to be repeated. This is considered a vaccine administration error. Determine how the error occurred and implement strategies to prevent it from happening again. Additionally, you are required to report COVID-19 vaccine administration errors to the Vaccine Adverse Event Reporting System (VAERSexternal icon).
No, the grace period cannot be used to schedule second doses. Administer doses as close to the 28-day interval as possible, but not earlier than recommended. The grace period should be used only for retrospectively reviewing records. If it is discovered a dose has been inadvertently administered within a grace period of ≤4 days from the recommended date for the second dose (i.e., 24–27 days after dose 1), the dose is considered valid.
You should administer the second dose as close as possible to the recommended interval of 28 days after dose 1. However, if it is not possible to follow the recommended interval, you may schedule the second dose of the Moderna COVID-19 Vaccine for administration up to 6 weeks (42 days) after the first dose. There are currently limited data on effectiveness of mRNA COVID-19 vaccines administered beyond this window. If the second dose is administered after these intervals, there is no need to restart the series.
We do not recommend that providers hold back stock for a second dose after administering a patient’s first dose. You should inform the patient that they need to return for the second dose.
COVID-19 vaccines are not interchangeable. The safety and effectiveness of a mixed-product series have not been evaluated. Every effort should be made to determine which vaccine product was administered as the first dose to ensure completion of the vaccine series with the same product. In exceptional situations:
- When the vaccine product administered for the first dose cannot be determined or is no longer available, you may administer any available mRNA COVID-19 vaccine, with a minimum of 28 days between doses. If two different mRNA COVID-19 vaccine products are administered, no additional doses of either product are recommended at this time.
- If a patient received the first dose of an mRNA COVID-19 vaccine but is unable to complete the series with either the same or a different mRNA COVID-19 vaccine (e.g., due to contraindication), you may consider administering a single dose of Janssen COVID-19 Vaccine, with a minimum of 28 days between doses. See contraindications and precautions for more information on use of Janssen COVID-19 Vaccine and additional precautions in people with a contraindication to mRNA COVID-19 vaccines.
Implement the following strategies to help ensure patients receive the second dose with the appropriate product and interval between doses:
- Provide a COVID-19 vaccination record card to every vaccine recipient. Ask recipients to bring their card to their appointment for the second dose. Encourage them to make a backup copy (e.g., by taking a picture of the card with their phone).
- Encourage vaccine recipients to enroll in v-safe, a free smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins as well as second-dose reminders.
- Encourage vaccine recipients to enroll in VaxTextSM, a free text-message-based platform, to receive reminders to get their second dose of COVID-19 vaccine.
- Record each recipient’s vaccination in the immunization information system (IIS).
- Record vaccine administration information in the patient’s medical record.
- Make an appointment for the second dose before the vaccine recipient leaves to increase the likelihood that patients will return to the same vaccination provider site for the second dose.
No. When the same mRNA vaccine product is temporarily unavailable, it is preferable to delay the second dose up to 6 weeks following the first dose to administer the same product rather than administer a mixed series using a different product.
Learn more about interchangeability of COVID-19 vaccine products.
No. You may administer COVID-19 vaccine and other vaccines without regard to timing. This includes simultaneous administration of COVID-19 vaccine and other vaccines on the same day, as well as coadministration within 14 days. It is unknown whether reactogenicity of COVID-19 vaccine is increased with coadministration, including with other vaccines known to be more reactogenic, such as adjuvanted vaccines or live vaccines.
When deciding whether to coadminister another vaccine(s) with COVID-19 vaccine, consider:
- Whether the patient is behind or at risk of becoming behind on recommended vaccines
- The patient’s risk of vaccine-preventable disease (e.g., during an outbreak or occupational exposures)
- The reactogenicity profile of the vaccines
Learn more about coadministration with other vaccines.
Yes, you may administer any currently authorized COVID-19 vaccine to people with underlying medical conditions; the Advisory Committee on Immunization Practices (ACIP) does not state a product preference. This includes people with:
- Immunocompromising conditions or people who take immunosuppressive medication or therapies
- Autoimmune conditions
- A history of Guillain-Barré syndrome
- A history of Bell’s palsy
- A history of dermal filler use
Learn more about vaccinating patients with underlying medical conditions.
Immunocompromised patients can receive any currently authorized COVID-19 vaccine; however, you should consider counseling them and timing immunosuppressive therapies.
Counsel immunocompromised patients about the:
- Unknown vaccine safety profile and effectiveness in immunocompromised populations
- Potential for reduced immune responses
- Need to continue to follow current guidance to protect themselves against COVID-19
Data are currently insufficient to inform optimal timing of COVID-19 vaccination and receipt of immunosuppressive therapies. However, based on general best practices for vaccination of immunocompromised people, ideally COVID-19 vaccination should be completed at least 2 weeks before initiation of immunosuppressive therapies. When it is not possible to administer a complete COVID-19 vaccine series (i.e., 2 doses of an mRNA vaccine or a single dose of Janssen COVID-19 Vaccine) in advance, you may still vaccinate patients receiving immunosuppressive therapy. Decisions to delay immunosuppressive therapy to complete COVID-19 vaccination should consider the patient’s risks related to their underlying condition.
At this time, revaccination is not recommended after patients regain immune competence. Recommendations on revaccination or additional doses of COVID-19 vaccines may be updated when more information is available.
Learn more about vaccinating patients with underlying medical conditions.
Yes. Pregnant or lactating people are eligible for and can receive any of the currently authorized COVID-19 vaccines; the ACIP does not state a product preference.
When making a decision about vaccination, you and your pregnant patient should consider the:
- Level of COVID-19 community transmission
- Patient’s personal risk of contracting COVID-19
- Risks of COVID-19 to the patient and potential risks to the fetus
- Known and potential benefits of vaccination
- Vaccine effectiveness
- Vaccine side effects
- Limited but growing evidence about the safety of COVID-19 vaccination during pregnancy
Encourage pregnant people who choose to be vaccinated to enroll in v-safe, a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after COVID-19 vaccination. A v-safe pregnancy registry has been established to follow outcomes among pregnant people who are vaccinated.
Learn more about vaccination of pregnant or lactating people.
Recommendations for vaccination depend on when a person has or had SARS-CoV-2 infection and when they received treatment.
People with a history of infection: Offer vaccination regardless of history of prior symptomatic or asymptomatic SARS-CoV-2 infection, including to people with prolonged post–COVID-19 symptoms.
While there is no recommended minimum interval between infection and vaccination, current evidence suggests that the risk of SARS-CoV-2 reinfection is low in the months after initial infection but may increase with time due to waning immunity.
People with a history of multisystem inflammatory syndrome in children (MIS-C) or adults (MIS-A): These people may choose to be vaccinated, but should consider delaying vaccination until they have recovered from their illness and for 90 days after the date of diagnosis. Considerations for vaccination may include:
- Clinical recovery from MIS-C or MIS-A, including return to normal cardiac function
- Personal risk of severe acute COVID-19 (e.g., age, underlying conditions)
- Level of COVID-19 community transmission and personal risk of reinfection
- Lack of safety data of COVID-19 vaccines following these illnesses
- Timing of any immunomodulatory therapies
People with a current infection: Defer vaccination of people with known current SARS-CoV-2 infection until the person has recovered from acute illness (if the person has symptoms) and until criteria have been met for them to discontinue isolation. This recommendation applies to any vaccine, including the first and second doses of COVID-19 vaccine.
People who previously received passive antibody therapy as part of COVID-19 treatment: Defer vaccination for at least 90 days after receipt of passive antibody therapy (monoclonal antibodies or convalescent plasma). This recommendation applies to people who receive passive antibody therapy before receiving any COVID-19 vaccine dose and to those who receive passive antibody therapy after the first dose of an mRNA COVID-19 vaccine but before the second dose, in which case the second dose should be deferred for at least 90 days following receipt of the antibody therapy.
Learn more about COVID-19 vaccination and SARS-CoV-2 infection.
Administer the second dose of Moderna COVID-19 vaccine 28 days after the first dose. The second dose may be administered up to 6 weeks (42 days) after the first dose, even though it may not be at least 90 days since the passive antibody therapy.
No, your patient may be vaccinated. Although people who have received passive antibody therapy as treatment for COVID-19 should wait at least 90 days before vaccination, there is no minimum interval between antibody therapies not specific to COVID-19 treatment and COVID-19 vaccination.
As with other vaccines, a moderate or severe illness is a precaution to receiving any currently authorized COVID-19 vaccine. It is not considered a contraindication. Generally, vaccination should be delayed until the acute illness has improved. However, if you and your patient feel the potential benefits of vaccination outweigh the potential risks, they may receive COVID-19 vaccine.
The following considerations can be used to help the provider conduct a risk assessment for COVID-19 vaccination:
- Risk of exposure to SARS-CoV-2 (e.g., living in a congregate setting, such as a long-term care facility; occupation)
- Risk of severe disease or death due to COVID-19 (e.g., because of age or underlying medical conditions)
- Whether the patient has previously been infected with SARS-CoV-2 and, if so, how long ago
- Note: Vaccination is recommended for people with a history of COVID-19; however, because the risk for reinfection is low in the months after initial infection, people with a precaution to vaccination and recent COVID-19 may choose to delay vaccination.
Contraindications to vaccination with Moderna COVID-19 Vaccine include
- Severe allergic reaction (e.g., anaphylaxis) after a previous dose or to a component of an mRNA COVID-19 vaccine (Moderna or Pfizer-BioNTech)
- Immediate allergic reaction of any severity to a previous dose or known (diagnosed) allergy to a component of the vaccine (see Appendix C for a list of vaccine components)
Do not vaccinate people with a contraindication. Consider referral to an allergist-immunologist or administering a different COVID-19 vaccine. You may consider Janssen COVID-19 Vaccine for people with a contraindication to mRNA COVID-19 vaccines (including a contraindication due to a known polyethylene glycol [PEG] allergy). People with a contraindication to mRNA COVID-19 vaccines have a precaution to Janssen COVID-19 Vaccine. In these cases, consider consultation with an allergist-immunologist to help determine if the patient can safely receive vaccination. Healthcare providers and health departments may also request a consultation from the Clinical Immunization Safety Assessment COVIDvax Project. Vaccination of these people should only be done in an appropriate setting under the supervision of a healthcare provider experienced in the management of severe allergic reactions. People who have received one mRNA COVID-19 vaccine dose but for whom the second dose is contraindicated should wait at least 28 days after the mRNA vaccine dose to receive Janssen COVID-19 Vaccine.
Learn more about COVID-19 vaccine contraindications and precautions.
Precautions for Moderna COVID-19 Vaccine include:
- History of an immediate allergic reaction to any other vaccine or injectable therapy (i.e., intramuscular, intravenous, or subcutaneous vaccines or therapies)
- Contraindication to Janssen COVID-19 Vaccine
- Moderate or severe acute illness
The following considerations can be used to help the provider conduct a risk assessment for vaccination of patients with a precaution to vaccination:
- Risk of exposure to SARS-CoV-2
- Risk of severe disease or death due to COVID-19
- Unknown risk of anaphylaxis (including fatal anaphylaxis) following COVID-19 vaccination in a person with a history of an immediate allergic reaction to other vaccines or injectable therapies
- Ability of the patient to be vaccinated in a setting where appropriate medical care is immediately available for anaphylaxis. For people with a contraindication to another type of COVID-19 vaccine (i.e., Janssen viral vector vaccine), vaccination with another type (i.e., mRNA vaccines) should only be done in an appropriate setting under the supervision of a healthcare provider experienced in the management of severe allergic reactions.
Learn more about COVID-19 vaccine contraindications and precautions.
PEG can be found in:
- Osmotic laxatives and oral bowel preparations for colonoscopy procedures
- Many medications as an inactive ingredient or excipient (e.g., certain injectable contraceptives, steroids)
- Some therapeutic medications (e.g., some chemotherapeutics)
Additionally, cross-reactive hypersensitivity can occur between PEG and polysorbates.
Screen patients for contraindications and precautions prior to vaccination. If a patient identifies a history of allergic reaction to a medication with which you are unfamiliar, you may consider using the following resources to determine if a specific medication contains PEG, a PEG derivative, or polysorbates:
- FDA package insert for the specific medication
- National Institutes of Health DailyMed databaseexternal icon
- CDC’s vaccine excipient summary
Yes. A side effect is not a contraindication to a second dose of mRNA COVID-19 vaccine. Common side effects to vaccination may include:
- Injection site pain, redness, or swelling
- Muscle pain
For most people, side effects last no longer than 1–2 days. Encourage patients to enroll in v-safe to tell CDC about any side effects after getting a COVID-19 vaccine and to receive reminders for a second dose.
People with an immediate allergic reaction to the first dose of an mRNA COVID-19 vaccine should not receive additional doses of either of the mRNA COVID-19 vaccines. An immediate allergic reaction to a vaccine or medication is defined as any hypersensitivity-related signs or symptoms consistent with urticaria, angioedema, respiratory distress (e.g., wheezing, stridor), or anaphylaxis that occur within 4 hours following administration. Attempt to determine whether reactions reported following vaccination are consistent with immediate allergic reactions versus other types of reactions commonly observed following vaccination, such as a vasovagal reaction or post-vaccination side effects (which are not contraindications to receiving the second vaccine dose).
People with a contraindication to mRNA COVID-19 vaccines may be able to receive Janssen COVID-19 Vaccine at least 28 days after the mRNA vaccine, but it is considered a precaution. In these cases, consider consultation with an allergist-immunologist to help determine if the patient can safely receive vaccination. Healthcare providers and health departments may also request a consultation from the Clinical Immunization Safety Assessment COVIDvax Project. Vaccination of these people should only be done in an appropriate setting under the supervision of a healthcare provider experienced in the management of severe allergic reactions.
See more information on:
There are two options for storing Moderna COVID-19 Vaccine. It may be stored in:
- Freezer between -50°C and -15°C (-58°F and 5°F) up to the expiration or beyond-use date (BUD). Keep vaccine vials in their box, and place in the storage unit.
- Refrigerator between 2°C and 8°C (36°F and 46°F) for up to 30 days prior to its first use. Do not refreeze.
Refer to the Moderna COVID-19 Vaccine product information or Moderna COVID-19 Vaccine Storage and Handling Summary for more detailed information on storage.
Yes. You should immediately examine shipments for signs of damage and to guarantee receipt of the appropriate vaccine types and quantities.
- Examine the shipping container and vaccines for signs of physical damage.
- Check the contents against the packing list to be sure they match.
- Immediately check vaccine expiration dates to ensure you have not received any expired or soon-to-expire products.
- Immediately check the cold chain monitor (CCM), a device used to monitor vaccine temperatures during transport (if one was included), for any indication of a temperature excursion during transit.
Yes. Before puncturing the vial stopper, vaccine may be stored in the refrigerator between 2°C and 8°C (36°F and 46°F) for up to 30 days. After 30 days, contact the manufacturer for guidance before discarding any vials.
After the first dose has been withdrawn, the vial should be held between 2°C and 25°C (36°F and 77°F). Discard after 12 hours. Do not refreeze.
CDC requires vaccination providers participating in the COVID-19 Vaccination Program to use a specific type of TMD called a “digital data logger” (DDL) to monitor temperatures. A DDL provides the most accurate storage unit temperature information, including details on how long a unit has been operating outside the recommended temperature range (referred to as a “temperature excursion”). DDLs using a buffered temperature probe provide the most accurate way to measure actual vaccine temperatures. Always use DDLs with a current and valid Certificate of Calibration Testing.
For more storage and handling information, see:
No. After the first dose has been withdrawn, vials must be stored between 2°C and 25°C (46°F and 77°F) and used within 12 hours.
If the vaccine experienced problems during shipment (for example, damage or temperature excursion), contact:
- McKesson Specialty Customer Service at (833) 343-2703, Monday–Friday, 8 AM–8 PM Eastern Time.
If the vaccine experienced problems after it was received and placed into storage, contact the vaccine manufacturer for guidance on improper storage and handling. For temperature excursions affecting Moderna COVID-19 Vaccine, see Moderna’s temperature excursion toolexternal icon.
For temperature excursions (out-of-range temperatures), take immediate action:
- Label the vaccine “Do Not Use” and store at the recommended temperature range until you receive manufacturer guidance.
- Document the date and length of time of the excursion, storage unit temperature, room temperature, and inventory affected.
- Record any other relevant information.
- Contact the manufacturer for guidance on whether to use affected vaccines and whether patients need to be recalled for revaccination.
- Document the event and action taken for record-keeping requirements.
There are two possible multidose vial presentations of Moderna COVID-19 Vaccine:
- Maximum of 11 doses per vial
- Maximum of 15 doses per vial
Each vial is clearly marked as containing either a maximum of 11 doses or a maximum of 15 doses. The label for the maximum of 15 doses per vial also has a distinctive blue shading on the bottom half of the vial.
CDC recommends healthcare providers follow the dosing guidance from the manufacturer as outlined in the Emergency Use Authorization (EUA)external icon. CDC will update its guidance if the EUA and ancillary supply kits support obtaining additional doses per vial in the future.
No. CDC recommends following these practices:
- Never combine or “pool” partial doses from two or more vials to obtain a full dose of vaccine.
- Withdraw only the number of doses authorizedexternal icon for the specific vaccine.
- Discard the vaccine vial and remaining vaccine if the amount of vaccine left in the vial is not a full dose.
Although no one wants to waste vaccine, it is crucial for infection control and patient safety to administer vaccine properly. Combining vaccine from multiple vials can result in cross-contamination, potentially causing bacterial infection in patients.
No, the dosage should NOT be adjusted regardless of the type of needles and syringes used. ALWAYS withdraw the amount of vaccine indicated by the manufacturer. For Moderna COVID-19 Vaccine, withdraw 0.5 mL into the syringe.
Contact the manufacturer. mRNA vaccine is very fragile and should not be shaken. Vials should only be gently swirled while held upright.
The route of administration for this vaccine is an intramuscular injection. Refer to the following CDC resources:
- Moderna COVID-19 Vaccine Preparation and Administration Summary
- Vaccine Administration: Intramuscular (IM) Injection Adults 19 years of age and older
- Vaccine Administration: Intramuscular (IM) Injection Children 7 through 18 years of age
- Resource Library includes demonstration videos for intramuscular injections
If Moderna COVID-19 Vaccine is administered as the first dose in an mRNA COVID-19 vaccine series to a patient that is age:
- Less than 12 years, do not give any additional dose at this time
- 12 through 17 years, you may administer Moderna COVID-19 Vaccine as the second dose. This is an off-label use, because Moderna COVID-19 Vaccine is not authorized in this age group.
If any of the currently authorized COVID-19 vaccines are administered subcutaneously, do not repeat the dose. If the dose given in error is the first dose, administer the second dose at the recommended interval of 28 days. If this dose is the second dose, the series is complete, and no additional doses are needed.
Inform the recipient of the potential for local and systemic adverse events.
Review resources on vaccine administration:
If a lower-than-authorized dose volume is administered for any of the currently authorized vaccines, adhere to the following interim recommendation:
- If more than half of the dose was administered, do not repeat the dose. If the dose given in error is the first dose, administer the second dose at the recommended interval of 28 days. If this dose is the second dose, the series is complete, and no additional doses are needed.
- If less than half of the dose was administered or the proportion of the dose cannot be estimated, administer the authorized dose immediately in the opposite arm. If the dose given in error is the first dose, administer the second dose at the recommended interval of 28 days from the date of receipt of the valid dose (not the date of receipt of the erroneous dose).
Interim recommendations for COVID-19 vaccine administration errors differ from ACIP’s general best practice guidelines. Review vaccine administration errors and deviations for COVID-19 vaccines to learn about the interim recommendation for each type of error.
For all vaccine administration errors:
- Inform the recipient of the vaccine administration error.
- Consult with the state immunization program or immunization information system (IIS) to determine how the dose should be entered into the IIS, both as an administered dose and to account for inventory.
- Report the error to the Vaccine Adverse Event Reporting System (VAERS) unless otherwise indicated in the Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Authorized in the United States. Providers are required to report all COVID-19 vaccine administration errors—even those not associated with an adverse event—to VAERSexternal icon.
- Determine how the error occurred and implement strategies to prevent it from happening again. A discussion on strategies to prevent errors can be found in the “Vaccine Administration” chapter of Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book). Additional resources can be found on CDC’s vaccine administration web page, including a job aid for preventing errors.
To reduce the risk of fake or counterfeit vaccines, dispose of vials and packaging as medical waste by placing vials in a sharps container and packaging in a red medical waste bag. If medical waste containers are in short supply, deface or safely crush packaging materials so they cannot be reintroduced or reproduced. After the products are sufficiently defaced or destroyed, dispose with regular waste.
The disposal process for unused COVID-19 vaccine and diluent may be different. For guidance, contact your jurisdiction’s immunization program.
Yes. CDC recommends the following observation periods after COVID-19 vaccination:
- 30 minutes for people with:
- History of an immediate allergic reaction of any severity to another vaccine or injectable therapy
- Contraindication to Janssen COVID-19 Vaccine who receive Moderna COVID-19 Vaccine
- History of anaphylaxis due to any cause
- 15 minutes for all other people
Before vaccination, counsel patients about expected local and systemic side effects.
Common side effects include:
- Muscle pain
Clinical trial data demonstrated vaccine efficacy was 94.1% against symptomatic, laboratory-confirmed COVID-19 following receipt of 2 doses of Moderna COVID-19 Vaccine.
Both doses are necessary for developing the most protection; effectiveness of a single dose has not been systematically evaluated.
CDC does not recommend predrawing vaccine. If vaccine must be predrawn:
- Set up a separate administration station for each vaccine type to prevent medication errors.
- Draw up vaccines only after arriving at the clinic site or mass vaccination event.
- Each person administering vaccines should draw up no more than one multidose vial or 10 doses* at one time.
- Monitor patient flow to avoid drawing up unnecessary doses.
- Predraw reconstituted vaccine into a syringe only when ready for administration.
- If predrawn vaccine is not used within 30 minutes of being reconstituted, follow manufacturer guidance for storage conditions and time limits.
*You may withdraw a total of 12 doses (2 multidose vials) of Pfizer-BioNTech COVID-19 Vaccine. This applies only to Pfizer-BioNTech COVID-19 Vaccine.
See CDC’s Vaccine Storage and Handling Toolkit for more information.
CDC recommends transporting vaccine in vials. However, there may be instances when the only option is to transport predrawn vaccine in a syringe. U.S. Pharmacopeia includes guidance for transporting predrawn vaccine in syringes in the USP COVID-19 Vaccine Toolkit: Operational Considerations for Healthcare Practitionersexternal icon.
Unpunctured vials can be transported for up to 12 hours. This time is cumulative, including the amount of transport time to and from clinics. All transport time is also included in the 30-day time frame. For example, if your transport time to and from a clinic is a total of 2 hours, any unpunctured vials have 10 hours of transport time left. If there is a clinic the following day, you may transport the vaccine again for up to 10 hours. Use Moderna COVID-19 Vaccine beyond-use date/time (BUD) tracking labels to track and record transport time. This only applies to unpunctured vials. Punctured vials must be discarded if not used within 12 hours.