Moderna COVID-19 Vaccine Questions
mRNA vaccines have strands of genetic material called mRNA inside a special coating. That coating protects the mRNA from enzymes in the body that would otherwise break it down. It also helps the mRNA enter the dendritic cells and macrophages in the lymph node cells near the vaccination site.
mRNA can most easily be described as instructions for the cell on how to make a piece of the “spike protein” that is unique to SARS-CoV-2. Since only part of the protein is made, it does not do any harm to the vaccinated person, but it is antigenic.
After the piece of the spike protein is made, the cell breaks down the mRNA strand and disposes of it using enzymes in the cell. The mRNA strand never enters the cell’s nucleus or affects genetic material.
Once displayed on the cell surface, the spike protein causes the immune system to begin producing antibodies which means the immune system is primed to protect against future infection.
The minimum order size and increment for Moderna COVID-19 vaccine is 100 doses (1 carton of 10 multidose vials, 10 doses per vial) per order.
Moderna COVID-19 vaccine is authorized and recommended for persons 18 years of age and older.
The recommendation for the Moderna COVID-19 vaccine should be implemented in conjunction with the Advisory Committee on Immunization Practice’s (ACIP) interim recommendations for allocating initial supply of COVID-19 vaccines.
All persons indicated for vaccination should receive 2 doses at least 1 month (28 days) apart. mRNA COVID-19 vaccines are not interchangeable with each other or with other COVID-19 vaccine products. The safety and efficacy of a mixed-product series have not been evaluated. Both doses of the series should be completed with the same product. However, if two doses of different mRNA COVID-19 vaccine products are inadvertently administered, no additional doses of either product are recommended at this time.
The need for and timing of booster doses for mRNA COVID-19 vaccines has not been established. No additional doses beyond the two-dose primary series are recommended at this time.
CDC considers history of the following contraindications to vaccination with both the Pfizer-BioNTech and Moderna COVID-19 vaccines:
- severe allergic reaction (e.g., anaphylaxis) after a previous dose of an mRNA COVID-19 vaccine or any of its components
- immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG])*
- immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG)*
* These persons should not receive mRNA COVID-19 vaccination at this time unless they have been evaluated by an allergist-immunologist and it is determined that they can safely receive the vaccine (e.g., under observation, in a setting with advanced medical care available). See Appendix B of interim clinical considerations for use of COVID-19 vaccines for more information on ingredients included in mRNA COVID-19 vaccines.
Precautions for both the Moderna and Pfizer-BioNTech COVID-19 vaccines include:
- moderate or severe acute illness
- history of an immediate allergic reaction* to any other vaccine or injectable therapy (except those related to a component of mRNA COVID-19 vaccines or polysorbate)
These persons should be counseled about the unknown risks of developing a severe allergic reaction and balance these risks against the benefits of vaccination. Deferral of vaccination and/or consultation with an allergist-immunologist may be considered until further information on the risk of anaphylaxis is available. Learn more about considerations that can be used to help the provider conduct a risk assessment for mRNA COVID-19 vaccination in these individuals.
* 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 four hours following administration.
Yes. You should screen for valid contraindications and precautions before administering any vaccine. CDC has a formpdf icon available for use when screening individuals for contraindications and precautions.
There are two options for storing Moderna COVID-19 vaccine. It may be stored in:
- Freezer between -25°C and -15°C (-13°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 Summarypdf icon for more detailed information on storage.
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.
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 6 hours. Do not refreeze.
CDC requires a specific type of TMD called a “digital data logger” (DDL). 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”). Unlike a simple minimum/maximum thermometer, which only shows the coldest and warmest temperatures reached in a unit, a DDL provides detailed information on all temperatures recorded at preset intervals.
Find additional guidance in CDC’s Vaccine Storage and Handling Toolkit.
No. Each multidose vial contains 10 doses. 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 6 hours.
Ancillary supplies will be packaged in kits and will be automatically ordered in amounts to match vaccine orders in VTrckS. Each kit will contain supplies to administer 100 doses of vaccine, including:
- 105 needles (various sizes for the population served by the ordering vaccination provider)
- 105 syringes (1 mL or 3 mL)
- 210 alcohol pads
- 100 vaccination record cards
- 1 needle gauge and length charts
- 2 face shields
- 4 surgical masks
Due to a limited supply of needles and syringes, specification of preferences for needles or syringes is not feasible. Products included in the kits may vary over time.
No. Moderna COVID-19 vaccine is a multidose vial that does not require reconstitution.
Each multidose vial of Moderna COVID-19 vaccine contains ten 0.5 mL doses.
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:
- COVID-19 Vaccine (Moderna) Preparation and Administration Summarypdf icon
- ‘Vaccine Administration: Intramuscular (IM) Injection Adults 19 years of age and olderpdf icon
- Vaccine Administration: Intramuscular (IM) Injection Children 7 through 18 years of agepdf icon
- HCP | Vaccine Administration | Resource Library | CDC includes demonstration videos for intramuscular injections
No. After removing a vial from the refrigerator, let it stand at room temperature for 15 minutes before administering vaccine.
Immunocompromised individuals may still receive COVID-19 vaccination if they have no contraindications to vaccination. However, they should be counseled about the
- unknown vaccine safety profile and effectiveness in immunocompromised populations
- the potential for reduced immune responses
- need to continue to follow all current guidance to protect themselves against COVID-19
Either of the currently authorized mRNA COVID-19 vaccines can be used when indicated; the Advisory Committee on Immunization Practices (ACIP) does not state a product preference.
For persons who were vaccinated for COVID-19 while they were undergoing chemotherapy or treatment with other immunosuppressive drugs and who have since regained their immune competence, re-vaccination is not recommended at this time. Recommendations on re-vaccination or additional doses of mRNA COVID-19 vaccines may be updated as additional information is available.
Immunocompromised individuals may still receive Moderna COVID-19 vaccination if they have no contraindications to vaccination. However, they should be counseled about the
- unknown vaccine safety profile and effectiveness in immunocompromised populations
- potential for reduced immune responses
- need to continue to follow all current guidance to protect themselves against COVID-19
- For persons who were vaccinated for COVID-19 while they were undergoing chemotherapy or treatment with other immunosuppressive drugs and who have since regained their immune competence, re-vaccination is not recommended at this time. Recommendations on re-vaccination or additional doses of mRNA COVID-19 vaccines may be updated as additional information is available.
Yes, but vaccination should be deferred for at least 90 days from receipt of treatment. Based on the estimated half-life of monoclonal antibodies or convalescent plasma as part of COVID-19 treatment, as well as evidence suggesting that reinfection is uncommon in the 90 days after initial infection, delaying vaccination for 90 days is a precautionary measure until additional information becomes available, to avoid interference of the antibody treatment with vaccine-induced immune responses.
Yes. Vaccination should be offered to eligible persons regardless of whether they have a history of prior symptomatic or asymptomatic SARS-CoV-2 infection. Data from clinical trials indicate that Moderna COVID-19 vaccine can be safely administered in persons with evidence of a prior SARS-CoV-2 infection.
Vaccination of persons with known current SARS-CoV-2 infection should be deferred until the person has recovered from acute illness (if the person had 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 Moderna COVID-19 vaccine. However, if a person was infected within the last 90-days, they may defer vaccination until after a 90-day period or if they were treated with monoclonal antibodies or convalescent plasma within the last 90 days vaccination should be deferred.
Yes. Persons with a history of Guillain-Barré Syndrome (GBS) may receive Moderna COVID-19 vaccine unless they have a contraindication to vaccination. With few exceptions, ACIP’s general best practice guidelines for immunization do not include history of GBS as a contraindication or precaution to vaccination. Any occurrence of GBS following mRNA COVID-19 vaccination should be reported to the Vaccine Adverse Event Reporting System (VAERS).
Yes. Persons with a history of Bell’s palsy may receive Moderna COVID-19 vaccine unless they have a contraindication to vaccination. Cases of Bell’s palsy were reported following vaccination in participants in both the Moderna and Pfizer-BioNTech COVID-19 vaccines clinical trials. However, the FDA does not consider these to be above the frequency expected in the general population and has not concluded that these cases were causally related to vaccination. Post-authorization safety surveillance will be important to further assess any possible causal association. In the absence of such evidence, persons with a history of Bell’s palsy may receive an mRNA COVID-19 vaccine unless they have a contraindication to vaccination. Any occurrence of Bell’s palsy following mRNA COVID-19 vaccination should be reported to VAERS.
Yes. A pregnant person who is part of a group recommended to receive COVID-19 vaccine (e.g., healthcare personnel) may choose to be vaccinated. When making a decision, you and your 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
- efficacy of the vaccine
- side effects of the vaccine
- lack of data about the vaccine during pregnancy
Yes. A lactating person who is part of a group recommended to receive a COVID-19 vaccine (e.g., healthcare personnel) may choose to be vaccinated. There are no data on the safety of COVID-19 vaccines in lactating people or the effects of mRNA COVID-19 vaccines on breastfed infant or milk production/excretion. mRNA vaccines are not thought to be a risk to the breastfeeding infant.
Yes. You should observe patients after vaccination to monitor for the occurrence of immediate adverse reactions.
- Persons with a history of an immediate allergic reaction of any severity to a vaccine or injectable therapy and persons with a history of anaphylaxis due to any cause: 30 minutes after vaccination
- All other persons: 15 minutes after vaccination
There should be a minimum interval of 14 days before or after administration with any other vaccines. However, if Moderna COVID-19 vaccine is inadvertently administered within 14 days of another vaccine, doses do not need to be repeated for either vaccine. Additionally, if the only opportunity for vaccination occurs during this 14-day interval and you do not expect the patient to return, you may vaccinate them.
No. Given the lack of data on the safety and efficacy of mRNA COVID-19 vaccines administered simultaneously with other vaccines, the vaccine series should be administered alone with a minimum interval of 14 days before or after administration with any other vaccines. If mRNA COVID-19 vaccines are inadvertently administered within 14 days of another vaccine, doses do not need to be repeated for either vaccine.
No. mRNA COVID-19 vaccines are not interchangeable with each other. The safety and efficacy of a mixed-product series have not been evaluated.
If a patient did not receive the brand of vaccine your practice stocks for the first dose, you may consider referring the patient to another provider. If you are expecting the same product soon, there is no maximum interval between the first and second dose for either vaccine. However, the second dose should be administered as close to the recommended interval as possible.
You should schedule the second dose of Moderna COVID-19 vaccine 28 days after the first dose (the recommended interval).
Second doses administered up to 4 days before the recommended date (4-day grace period) are considered valid. This means that when retrospectively reviewing records, a second dose of Moderna COVID-19 vaccine administered 24 of more days after the first dose is considered valid.
However, if a dose is inadvertently administered before the 4-day grace period, it does not need to be repeated. This means that when retrospectively 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.
The 4-day grace period should be used when retrospectively evaluating records and not to schedule appointments. Appointments for a second dose should be scheduled to meet the recommended interval.
Adverse reactions are usually mild to moderate in intensity and resolve within a few days. The most common adverse reactions reported after vaccination in clinical studies included:
- Pain at injection site (92.0%)
- Fatigue (70.0%)
- Headache (64.7%)
- Muscle pain (51.5%)
- Joint pain (46.4%)
- Chills (45.4%)
- Nausea/vomiting (23.0%)
- Axillary swelling and tenderness of the vaccination arm (19.8%)
- Fever (15.5%)
- Injection site swelling (14.7%)
- Injection site redness (10.0%)
Preliminary data suggest high vaccine efficacy (94.1%) in preventing COVID-19 following receipt of two doses of Moderna COVID-19 vaccine.
Both doses are necessary for protection; efficacy of a single dose has not been systematically evaluated.
Prior receipt of a COVID-19 vaccine will not affect the results of nucleic acid amplification or antigen tests (viral tests).
Currently available antibody tests for SARS-CoV-2 assess IgM and/or IgG to one of two viral proteins: spike or nucleocapsid. Because both the Pfizer-BioNTech and Moderna COVID-19 vaccines targets the spike protein, a positive test for spike protein IgM/IgG could indicate either prior infection or vaccination. To evaluate for evidence of prior infection in an individual with a history of mRNA COVID-19 vaccination, a testexternal icon specifically evaluating IgM/IgG to the nucleocapsid protein should be used. Antibody testing is not currently recommended to assess for immunity to COVID-19 following mRNA COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.