Janssen COVID-19 Vaccine (Johnson & Johnson) Questions

Below are answers to commonly asked clinical questions about Janssen COVID-19 Vaccine. Get answers to other frequently asked questions:

Janssen COVID-19 Vaccine and Risk of Thrombosis with Thrombocytopenia Syndrome (TTS)

TTS is a rare syndrome that involves acute venous or arterial thrombosis and new-onset thrombocytopenia in patients with no recent known exposure to heparin. Although the mechanism that causes TTS is not fully understood, TTS appears to be similar to heparin-induced thrombocytopenia, a rare reaction to heparin treatment.

A more detailed interim case definition of TTSexternal icon is available from the Brighton Collaboration.

ACIP reviewed a risk-benefit assessment of TTS that took into account:

  • The rate and characteristics of TTS cases
  • Recent COVID-19 epidemiology
  • Modeling and population- and individual-level risk-benefit analysis results to quantify COVID-19 hospitalizations, ICU admissions, and deaths prevented with resumption of use of the Janssen COVID-19 Vaccine in the United States
  • Data from jurisdictional COVID-19 vaccination programs about whether changes to ACIP recommendations would disproportionately affect certain populations

For more information on this assessment, see:

The primary symptoms of TTS following vaccination include:

  • Shortness of breath
  • Chest pain
  • Leg swelling
  • Persistent abdominal pain
  • Severe or persistent headaches or blurred vision
  • Easy bruising or tiny blood spots under the skin beyond the injection site

See the American Society of Hematology’s guidance for more detailed information on the diagnosis and management of TTSexternal icon.

We are still learning about TTS after Janssen COVID-19 vaccination. As of April 23, 2021, the highest rates of TTS per Janssen vaccine doses administered were identified in women younger than 50 years of age. Women younger than 50 years of age should be made aware of a rare but increased risk of blood clots with low platelets following vaccination and that there are other COVID-19 vaccines available for which this specific risk has not been seen. Provide recipients or caregivers (as applicable) the EUA Fact Sheet for Recipients and Caregiversexternal icon.

Weekly updates on TTS are available at Selected Adverse Events Reported after COVID-19 Vaccination.

Reports of TTS following the use of Janssen COVID-19 Vaccine indicate onset of symptoms began approximately 1 to 2 weeks after vaccination. We recommend that for 3 weeks after receiving this vaccine, patients should be aware of possible symptoms of a blood clot with low platelets and seek medical care immediately if these symptoms occur.

For more information, see Updated Recommendations from the Advisory Committee on Immunization Practices for Use of the Janssen (Johnson & Johnson) COVID-19 Vaccine After Reports of Thrombosis with Thrombocytopenia Syndrome Among Vaccine Recipients — United States, April 2021.

The clinical presentation of the reported cases among recipients of the Janssen COVID-19 Vaccine (which is based on a human adenoviral vector) is similar to that of recently reported cases from Europe after receipt of the AstraZeneca COVID-19 Vaccine (which is based on a chimpanzee adenoviral vector). The AstraZeneca COVID-19 Vaccine is not currently authorized for use in the United States.

Adverse events that occur after receipt of any COVID-19 vaccine should be reported to the Vaccine Adverse Event Reporting System (VAERS). Information on how to submit a report to VAERS is available at https://vaers.hhs.gov/index.htmlexternal icon or 1-800-822-7967.

Healthcare providers are required to report to VAERS the following adverse events after COVID-19 vaccination:

  • Vaccine administration errors
  • Serious adverse events
  • Multisystem inflammatory syndrome
  • Cases of COVID-19 that result in hospitalization or death

You should screen patients for a history of or risk factor for a blood clotting disorder. People with a history of an episode of immune-mediated syndrome characterized by thrombosis and thrombocytopenia (e.g., heparin-induced thrombocytopenia) should be offered another FDA-authorized COVID-19 vaccine (i.e., mRNA vaccine) if it has been 90 days or less since their illness resolved. After 90 days, patients may be vaccinated with any FDA-authorized COVID-19 vaccine.

People with a history of other types of clotting disorders and people with risk factors for clotting disorders can be vaccinated with any FDA-authorized vaccine, including the Janssen COVID-19 Vaccine.

CDC has a Prevaccination Checklist for COVID-19 Vaccines that you can use to screen patients for COVID-19 vaccines.

Most people with a history of or risk factors for blood clotting disorders CAN receive Janssen COVID-19 Vaccine. Venous thromboembolism (VTE), defined as deep vein thrombosis, pulmonary embolism, or both, is common. The biologic mechanisms for VTE (as well as arterial thrombi) differ from the underlying immune-mediated mechanism for heparin-induced thrombocytopenia (HIT). Based on current knowledge, experts believe that people with risk factors for VTE (e.g., inherited or acquired thrombophilia including Factor V Leiden, prothrombin gene 20210A mutation, antiphospholipid syndrome, protein C, protein S, or antithrombin deficiency), or a history of other types of thromboses (including cerebral venous sinus thrombosis) not associated with thrombocytopenia are unlikely to be at increased risk for TTS. These people can receive any FDA-authorized vaccine, including the Janssen COVID-19 Vaccine.

As stated above, as an exception, people with a history of an episode of an immune-mediated syndrome characterized by thrombosis and thrombocytopenia, such as HIT, should be offered another FDA-authorized COVID-19 vaccine (i.e., mRNA vaccine) if it has been 90 days or less since their illness resolved. After 90 days, patients may be vaccinated with any FDA-authorized COVID-19 vaccine.

Provide the EUA Fact Sheet for Recipients and Caregiversexternal icon to anyone who chooses to be vaccinated with the Janssen COVID-19 Vaccine.

See Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Authorized in the United States for more information.

People using hormonal birth control can receive any FDA-authorized COVID-19 vaccine. There are no recommendations to stop taking hormonal birth control (birth control pills, implant, patch, ring, or shot) before or after receiving the Janssen COVID-19 Vaccine. Although the risk of blood clots is increased with some hormonal birth control methods (e.g., certain types of birth control pills, patch, ring), based on the available data, experts believe that these factors do not make people more likely to develop TTS after receiving the Janssen COVID-19 Vaccine. All women younger than 50 years of age (regardless of their birth control use) should be aware of the rare but increased risk for TTS following vaccination with the Janssen COVID-19 Vaccine. There are other COVID-19 vaccines available (i.e., mRNA vaccines) for which this specific risk has not been seen.

Pregnant or recently pregnant people can receive any FDA-authorized COVID-19 vaccine. Based on available data, experts believe that being pregnant or recently pregnant does not make someone more likely to develop TTS after receiving the Janssen COVID-19 Vaccine. All women younger than 50 years of age—regardless of whether they are pregnant or recently pregnant—should be aware of the rare but increased risk for TTS. There are other COVID-19 vaccines available (i.e., mRNA vaccines) for which this specific risk has not been seen. CDC continues to collect information from people vaccinated during all trimesters of pregnancy about their health and the health of their babies up to 3 months old to understand the benefits and risks of COVID-19 vaccination during pregnancy.

You may consider referring the patient to another provider or the state or local immunization program. You or your patient may use Vaccines.gov to find a location that stocks other brands.

Your strong recommendation can help patients make an informed decision and feel confident about getting vaccinated against COVID-19.

  1. Explain that the available data show that the vaccine’s known and potential benefits outweigh its known and potential risks.
  2. Discuss the possibility of a rare risk of blood clots with low platelets seen after receipt of the Janssen COVID-19 Vaccine.
    1. To date, most of these reports have been in adult women younger than 50 years old, but there have been reports in men and older women.
    2. The reporting rate for this event in women 18 through 49 years old is about 7 per 1 million women vaccinated, so this event is rare.
    3. The reporting rate for both women 50 years and older and men is less than 1 per 1 million people vaccinated.
  3. Explain that that there are other COVID-19 vaccine options available for which this specific risk has not been seen.
    1. Consider and discuss if the patient will be able and willing to complete a two-dose mRNA vaccine series.
  4. Emphasize that CDC and FDA will continue to monitor the safety of all COVID-19 vaccines.
    1. The safety monitoring systems are working. The detection of TTS as a rare adverse event shows that safety monitoring systems, like VAERSexternal icon, are working efficiently to detect unusual or unexpected patterns of adverse events.
  5. Encourage them to seek medical care right away if they develop any symptoms of TTS after receiving the Janssen COVID-19 Vaccine. Symptoms include:
    • Shortness of breath
    • Chest pain
    • Leg swelling
    • Persistent abdominal pain
    • Severe or persistent headaches or blurred vision
    • Easy bruising or tiny blood spots under the skin beyond the injection site

Materials to help you communicate with patients about the Janssen COVID-19 Vaccine:

Ideally, you should use the most up-to-date version. You may provide the EUA Fact Sheet for Recipients and Caregiversexternal icon via hard copy and/or electronic means. If you already have a large supply of fact sheets printed, you may use these only if you also provide all information added in the updated version. This means:

  • If you have printed versions dated 3/19/21, you need to provide the updates contained on page 3 of the 4/23/21external icon version (risks of the Janssen COVID-19 Vaccine).
  • If you have printed versions dated 2/27/21, you need to provide the updates contained on page 3 (risks of the Janssen COVID-19 Vaccine) and page 6 (administration fee and reporting suspected fraud) of the 4/23/21external icon version.

Vaccine Supply and Distribution

The minimum order size and increment for Janssen COVID-19 Vaccine is 100 doses (2 cartons of 10 multidose vials, 5 doses per vial) per order.

Vaccination Schedule and Use

Janssen COVID-19 Vaccine is authorized and recommended for people 18 years of age and older.

All people for whom vaccination is indicated should receive 1 dose of Janssen COVID-19 Vaccine.

COVID-19 vaccines are not interchangeable. The safety and effectiveness of a mixed-product series have not been evaluated. In most cases, if patients begin a series with an mRNA COVID-19 vaccine, they should complete the series with the same product. In limited, exceptional situations where a patient received the first dose of an mRNA COVID-19 vaccine but is unable to complete the series with either the same or different mRNA COVID-19 vaccine (e.g., due to contraindication), you may consider a single dose of the Janssen COVID-19 Vaccine, with a minimum interval of 28 days between doses. See the Contraindications and Precautions section of CDC’s Interim Clinical Considerations for Use of COVID-19 Vaccines for additional information on use of the Janssen COVID-19 Vaccine and additional precautions for people with a contraindication to mRNA COVID-19 vaccines.

No. You may administer COVID-19 vaccine and other vaccines without regard to timing. This includes simultaneous administration of COVID-19 vaccines 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, occupational exposures)
  • The reactogenicity profile of the vaccines

Learn more about coadministration with other vaccines.

Vaccine Indications

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 as recommended below.

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 two 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 the Janssen COVID-19 Vaccine) in advance, you may still vaccinate patients on 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 Advisory Committee on Immunization Practices (ACIP) does not state a product preference. However, you should talk to pregnant, lactating, and postpartum people younger than 50 years of age who choose to receive the Janssen COVID-19 Vaccine about:

  • The rare but increased risk of TTS after receipt of this vaccine
  • The availability of other FDA-authorized COVID-19 vaccines (i.e., mRNA vaccines) this risk has not been observed

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
  • 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. CDC established a v-safe pregnancy registry to follow outcomes among pregnant people who are vaccinated.

Learn more about vaccination of pregnant or lactating people and considerations for use of the Janssen COVID-19 Vaccine in certain populations.

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 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.

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 a 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; or 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 of 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 and Precautions

Contraindications to vaccination with the Janssen COVID-19 Vaccine include:

  • Severe allergic reaction (e.g., anaphylaxis) to a component of the Janssen COVID-19 Vaccine
  • Immediate allergic reaction of any severity 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 mRNA COVID-19 vaccination for people with a contraindication to the Janssen COVID-19 Vaccine (including a contraindication due to a known polysorbate allergy). People with a contraindication to the Janssen COVID-19 Vaccine have a precaution to mRNA vaccines. 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.

Learn more about COVID-19 vaccine contraindications and precautions.

Precautions for the Janssen 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 an mRNA 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., mRNA vaccines), vaccination with another type (i.e., Janssen viral vector vaccine) 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.

People with a contraindication to mRNA COVID-19 vaccines may be able to receive the Janssen COVID-19 Vaccine at least 28 days after the mRNA vaccine, but it is considered a precaution. In these cases, consider consulting 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:

Vaccine Storage and Handling

Store the Janssen COVID-19 Vaccine in the refrigerator between 2°C and 8°C (36°F and 46°F) until the expiration or beyond-use date (BUD). Do NOT store vaccine in the freezer. Refer to the Janssen COVID-19 Vaccine product information or Janssen COVID-19 Vaccine Storage and Handling Summary for more information.

Yes. After first puncturing the vial, the vial should be held between 2°C and 8°C (36°F and 46°F) for up to 6 hours OR at room temperature (up to 25°C [77°F]) for up to 2 hours.

See Janssen COVID-19 Vaccine Storage and Handling Summary for more storage and handling information.

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 vaccine 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 vial is first punctured, the vaccine vial may be held:

  • For up to 2 hours at room temperature; discard any vaccine not used within 2 hours
    —–OR—-
  • For up to 6 hours refrigerated between 2°C and 8°C; discard any vaccine not used within 6 hours

You should not add these time limits together (i.e., you may not hold the vaccine at room temperature for 2 hours and then hold it refrigerated for another 6 hours).

If you do not reach the 2-hour time limit at room temperature, you may transfer the punctured vial to a refrigerated storage unit between 2°C and 8°C for the remaining time, up to 2 hours. For example, a vial held at room temperature for 1 hour after first puncture can be stored in the refrigerator (between 2°C and 8°C) for no more than 1 hour before using or discarding. If the 2-hour time limit at room temperature has been reached, the vaccine must be discarded and cannot be transferred to the refrigerator.

See Janssen COVID-19 Vaccine Storage and Handling Summary for more storage and handling information.

The allowed storage time after first vial puncture or dose withdrawal is either a maximum of 6 hours refrigerated or 2 hours at room temperature. These maximum hold times and temperatures are not cumulative. You should discard the punctured vial once it exceeds either of these conditions, even if there are doses remaining. If stored in the refrigerator after the first puncture, the vaccine can be moved to room temperature for brief periods of time for administration. This does not affect the maximum 6-hour hold period for vaccine stored in the refrigerator.

See Janssen COVID-19 Vaccine Storage and Handling Summary for more storage and handling information.

If the vaccine experienced problems during shipment (for example, damage or temperature excursion), contact:

Centrally distributed vaccine (for example, Janssen): 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 (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.

Vaccine Administration

No. The Janssen COVID-19 Vaccine comes in a multidose vial and does not require reconstitution.

See Janssen COVID-19 Vaccine Preparation and Administration Summary for more information.

Each multidose vial of the Janssen COVID-19 Vaccine contains five 0.5 mL doses.

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 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 doses 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 the Janssen COVID-19 Vaccine, withdraw 0.5 mL into the syringe.

If the Janssen COVID-19 Vaccine is inadvertently administered to a patient age 16 through 17 years, do not repeat the dose with the Pfizer-BioNTech COVID-19 Vaccine.

This is considered a vaccine administration error. Determine how the error occurred and implement strategies to prevent it from happening again. Report this error to VAERSexternal icon.

If any of the currently authorized COVID-19 vaccines are administered subcutaneously, do not repeat the dose. No additional doses are needed.

Inform the recipient of the potential for local and systemic adverse events.

This is considered a vaccine administration error. Determine how the error occurred and implement strategies to prevent it from happening again. Report this error to VAERSexternal icon.

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. 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.

This is considered a vaccine administration error. Determine how the error occurred and implement strategies to prevent it from happening again. Report this error to VAERSexternal icon.

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:

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:
    • A history of an immediate allergic reaction of any severity to another vaccine or injectable therapy
    • A contraindication to an mRNA COVID-19 vaccine who receive the Janssen COVID-19 Vaccine
    • History of anaphylaxis due to any cause
  • 15 minutes for all other people

Vaccine Safety and Efficacy

Before vaccination, counsel patients about expected local and systemic side effects.

Common side effects include:

Local reactions:

  • Pain
  • Redness
  • Swelling

Systemic reactions:

  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Fever
  • Nausea

Women younger than 50 years old should be made aware of the rare but increased risk of blood clots with low platelets following vaccination and the availability of other COVID-19 vaccines where this risk has not been observed. Provide recipients or caregivers (as applicable) the EUA Fact Sheet for Recipients and Caregiversexternal icon.

Clinical trial data demonstrated vaccine efficacy was 66.3% at least 14 days after vaccination against symptomatic, laboratory-confirmed COVID-19 in persons without evidence of previous SARS-CoV-2 infection; 93.1% for the prevention of COVID-19-associated hospitalization; and 75% against all-cause death.

Learn more about Janssen COVID-19 Vaccine’s efficacy.

Off-Site Clinics

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.

Page last reviewed: June 15, 2021