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Division of Communicable Disease Control


Mpox Vaccine Provider and Local Health Department Q&A

December 8, 2022

Mpox Vaccine Eligibility

What options are available for mpox vaccination?

Two vaccines are available for mpox vaccination:

  • JYNNEOS: This is a live, non-replicating vaccine;. It is Food and Drug Administration (FDA) licensed for prevention of smallpox and mpox in people 18 years or older, as well as under Emergency Use Authorization (EUA) for people younger than18 years old. Current supply is limited. JYNNEOS is approved as a series of two doses given 28 days apart.
  • ACAM2000: This is a live, replicating vaccine containing vaccinia virus; FDA-licensed for prevention of smallpox. This vaccine has not been distributed in California during the current mpox outbreak as; the JYNNEOS vaccine has been the preferred option.

At this time, the California Department of Public Health (CDPH) is recommending the JYNNEOS vaccine for general vaccination. There is currently adequate vaccine supply of JYNNEOS, there are no longer "eligibility" criteria, and vaccine providers can offer the vaccine to any patients who MAY be at risk, and persons who request vaccination should receive it without having to attest to specific risk factors. 

Who should be highly encouraged to receive the mpox vaccination? 

CDPH recommends that those who may be at risk for, or who seek additional protection from, mpox infection, as defined within this guidance, be vaccinated against mpox.

While specific eligibility criteria have been removed, prioritizing the education and vaccination of populations at highest risk is encouraged to decrease infections, minimize serious illness, and prevent fatalities.

Vaccination efforts should be prioritized for:

  • Anyone living with human immunodeficiency virus (HIV). It is recommended that additional efforts be made to reach those with a CD4 count <350/mm3, an unsuppressed HIV viral load, or an opportunistic infection, due to increased risk for complications of mpox
  • Any man or trans person who has sex with men or trans persons
  • People who use or who are eligible for HIV pre-exposure prophylaxis (PrEP)
  • Sex workers
  • Sexual partners of the above groups
  • People who have had direct skin-to-skin contact with one or more people AND who know others in their community that have had mpox infection
  • People who have been diagnosed with a bacterial sexually transmitted disease (STD) (e.g., chlamydia, gonorrhea, syphilis) in the past 3 months
  • People who anticipate experiencing the above risks

Each local health department (LHD) should assess local circumstances and needs for mpox vaccination based on local morbidity, infection rate, and populations at risk.

LHDs and vaccine providers are strongly recommended to consider vaccine equity when planning vaccination activities.

  • Vaccines should be shared with medical providers and/or CBOs that can reach diverse populations that are at risk of mpox exposure.          
  • Priority should be given to making vaccines accessible to populations who have been disproportionately affected by mpox and populations who have lower vaccination rates such as Black and Latino individuals. See the CDPH Mpox Health Equity page for more information.
  • Priority should also be given to persons at risk for mpox exposure who are:
    • Incarcerated
    • Currently experiencing homelessness or intermittent homelessness
    • Living in residential substance use treatment centers or participating in substance use treatment programs

For further details, see the CDPH Considerations for Mpox Vaccination in California guidance. 

How can we be more equitable in our vaccination efforts?

CDPH encourages healthcare providers to consider outreach efforts focused on improving vaccination rates in groups over-represented in cases. Healthcare providers should utilize all available tools and outreach messaging platforms to reach out to these populations, encourage vaccination and return for second doses, and be flexible on vaccination route to overcome barriers. The use of clear messaging and inclusive language are important factors in improving outreach and education, following vaccination rates. Please visit the CDPH Mpox Health Equity Page or the CDC Vaccine Equity Toolkit for more information.  

Who should be offered mpox vaccination due to the risk for occupational exposure?  

The Center for Disease Control and Prevention (CDC) and CDPH recommend mpox vaccination for people at risk for occupational exposure to Orthopoxviruses, including: 

  • Occupational groups recommended for vaccination by Advisory Committee on Immunization Practices (ACIP).
  • Healthcare workers (HCWs) who are likely to collect laboratory specimens from patients with mpox (e.g., persons working in sexual health clinics or clinical settings that serve at-risk populations).

HCWs should follow current CDC infection control recommendations for healthcare facilities, including use of personal protective equipment (PPE), when examining patients with symptoms consistent with mpox. PPE is readily available in healthcare facilities and is expected to be extremely effective at preventing transmission of mpox. For more guidance, please visit the Mpox Q&A Site within the Recommended Infection Control Practices to Prevent Transmission of Mpox in Healthcare Settings section. Healthcare providers who may have unusual exposures to mpox in the workplace should consult with their local health department about vaccination. 

Who should be offered the mpox vaccine after mpox exposure to a confirmed or probable case?

Contacts to people with positive Orthopoxvirus or mpox testing results (and contacts to high-suspicion cases awaiting laboratory results) are eligible for post-exposure prophylaxis (PEP).

Who should be offered the mpox vaccine after mpox exposure to a suspected case?

PEP for contacts of highly suspected cases with pending Orthopoxvirus testing results are eligibile for mpox vaccine.

What is the time window for offering the mpox vaccine after an exposure?

PEP can be given up to 14 days from the time of last exposure.[1] PEP given within 4 days of the exposure may prevent onset of disease. PEP given 4-14 days after the exposure may reduce the symptoms of the disease but may not prevent the disease. PEP given 4-14 days after the exposure may reduce the symptoms of the disease but may not prevent the disease. It may be reasonable to consider PEP for certain exposures greater than 14 days prior, such as high-risk exposure in a high-risk person at significant risk for severe disease (e.g., for a severely immunosuppressed person with a recent sex partner confirmed to have mpox).

Should the mpox vaccine be given to symptomatic contacts of confirmed or probable cases?

  • For contacts with symptoms suspicious for mpox infection (e.g. fever, rash), if testing is pending, it is reasonable to defer vaccination until test results are available; otherwise, PEP should be offered.
  • If symptoms are nonspecific (e.g., fatigue, mild respiratory symptoms without rash), offering PEP at the time of contact interview/testing maximizes the opportunity for prophylaxis and can be considered, especially if the contact is at risk for severe disease (age less than 8 years, pregnant, immunocompromised, history of atopic dermatitis or other exfoliative skin conditions).  
    • Contacts with nonspecific symptoms (e.g., fatigue) may have an alternate diagnosis.  

 What are the benefits of mpox vaccination?

  • PEP may prevent mpox disease if given within 4 days of exposure and may attenuate the severity of infection if given within 4-14 days of exposure.
  • Vaccination prior to exposure can prevent mpox disease. Please refer below to vaccine effectiveness and the JYNNEOS FDA product inserts for a description of data used to establish vaccine efficacy.  JYNNEOS relied on antibody-based studies. Vaccine safety and effectiveness studies are ongoing during the current mpox outbreak.

What are risks of mpox vaccination?

  • Common adverse events: injection site reactions (pain/redness/swelling), systemic adverse reactions (muscle pain, headache, fatigue).
  • Serious adverse events are uncommon.
  • Please refer to the JYNNEOS FDA Product Insert for full details.
  • The CDC JYNNEOS website provides guidance for pre- and post-vaccination counseling. 

What are contraindications and precautions to mpox vaccination?

  • Severe allergic reaction (e.g., anaphylaxis) to a prior dose of JYNNEOS.
  • People with a history of anaphylaxis to vaccine component (gentamicin, ciprofloxacin, egg protein) are considered to have a precaution to vaccination. Providers should discuss risks and benefits with potential recipients. They may be vaccinated with a 30-minute observation period. Alternatively, taking into account the risk of acquiring mpox if the vaccination is delayed, an allergist-immunologist may be consulted before the vaccine is administered.
  • People of any age with a history of keloids should receive subcutaneous dosing of JYNNEOS.
  • Please refer to the JYNNEOS FDA Product Insert for full details.
  • Please refer to the CDC Table of Contraindications for JYNNEOS and ACAM2000 Vaccination.

Should a person who had a previous smallpox vaccination still receive mpox vaccination?

  • CDC recommends that those persons with a remote history of smallpox vaccination (e.g., received smallpox vaccination as a child) should still receive a 2-dose JYNNEOS vaccine series.
  • Persons who have received the smallpox vaccine primary series and booster doses as part of an occupational medicine program due to risk of occupational exposure (e.g., laboratorians who work with Orthopoxviruses) are recommended to receive a single (1) JYNNEOS booster vaccine.


How can providers order JYNNEOS vaccine?

Healthcare providers should work with their local health department to obtain the JYNNEOS vaccine.

Where do I send my patients to get vaccinated?

Mpox vaccine is available through local public health departments and some community providers. To find the nearest vaccination location, contact your local health department.

Where is the provider agreement for JYNNEOS vaccine? 

The Provider agreement form can be found at CDC Mpox Vaccination Program Provider Agreement site.

Vaccine in Specific Populations

Can JYNNEOS be given to pregnant people? Can JYNNEOS be given to people who are breastfeeding?

JYNNEOS can be offered to people who are pregnant or breastfeeding who are otherwise eligible. The risks and benefits of JYNNEOS should be discussed with the patient using shared decision-making. Current available human data on JYNNEOS administered to pregnant women are insufficient to inform vaccine associated risks in pregnancy. However, animal models, including rats and rabbits, have shown no evidence of harm to a developing fetus. Mpox infection during pregnancy is associated with complications, including severe congenital infection, pregnancy loss, and maternal morbidity and mortality.

It is unknown whether JYNNEOS is excreted in human milk. Data is not yet available to assess the effects of JYNNEOS in the breastfed infant or on milk production. However, because JYNNEOS vaccine is replication-deficient, it likely does not present a risk of transmission to breastfed infants. 

Pediatric Vaccination

Can JYNNEOS vaccine be given to children younger than 18 years old?

JYNNEOS is licensed by the FDA for use in the prevention of mpox in people ages 18 years and older. Use in people under 18 years old is available by emergency use authorization (EUA) from FDA and CDC for immunization by subcutaneous (SC) injection for prevention of mpox disease in individuals determined to be at high risk for mpox infection.

Do parents need to consent for minors receiving JYNNEOS vaccine?

A minor who is 12 years old or older who may have come into contact with mpox may receive JYNNEOS vaccine without parent or guardian consent as part of medical care related to the diagnosis or treatment of mpox, because mpox is a communicable disease reportable under law to the local Health Officer. (California Family Code § 6926(a).) For more information, please see consent for medical services for the treatment of mpox in California minors.

Vaccine Storage & Handling

Where can I find detailed storage and handling information for JYNNEOS vaccine?

Providers may refer to CDC's JYNNEOS storage & handling guidance.

How long can JYNNEOS vaccine be stored refrigerated 2°C to 8°C (36°F to 46°F) after thawing?

Unpunctured vials may be stored in the refrigerator for up to 8 weeks. Punctured vials may be stored continuously in the refrigerator for up to 8 hours.

How long can JYNNEOS vaccine be stored at room temperature 8°C to 25°C (46°F to 77°F)?

Unpunctured vials may be held at room temperature for up to 6 cumulative hours.

Once the vaccine has been drawn up in syringes, can those pre-drawn syringes be stored in refrigerated temperatures for up to 8 hours (ex: for mass vaccination events)?

 Yes, but these must be used within 8 hours. 

Vaccine Administration

Can doses from two vials be combined into a single shot?


What if I can't get 5 doses per vial?

There has been variation in the ability to draw 5 doses per vial for intradermal administration (ranging from 3-5), depending on technique and supplies used.

When should someone get their second dose of JYNNEOS vaccine?

JYNNEOS is licensed by FDA for a 2-dose series given at an interval of 28-days. Per CDC guidance, a dose given up to 4 days early is considered valid (24 days after the first dose). If the second dose is administered beyond 28 days, the first dose does not need to be repeated.

What is CDPH policy on second doses? 

CDPH currently recommends that all persons who received their first dose of JYNNEOS vaccine receive a second dose at the appropriate interval (at least 28 days apart).

A person who is diagnosed with mpox after their first dose of JYNNEOS is not recommended to receive the second dose at this time (unless they are immunocompromised), because mpox infection likely confers additional immune protection. 

Can JYNNEOS vaccine dosing regimens be interchangeable?

When necessary, for eligible individuals, the dosing regimens are interchangeable. For example, a person aged 18 years or older who received their first JYNNEOS vaccine dose with the standard subcutaneous regimen may receive a second dose with the alternative intradermal regimen at the recommended interval (i.e., 28 days) to complete the vaccination series. Another example is, a person who received the first dose intradermally, may receive the second dose subcutaneously.

What is the vaccine effectiveness for the JYNNEOS vaccine?

Studies on the effectiveness of JYNNEOS vaccine to prevent mpox are ongoing. An initial study published by the CDC in a recent MMWR found that mpox incidence was 14 times higher in unvaccinated males aged 18-49 years who were at risk for mpox exposure, compared to those at risk who had received at least one dose of vaccine greater than or equal to 14 days prior to mpox exposure. There are several limitations to this study, but these initial findings are encouraging.  

Where can I find standing orders for JYNNEOS vaccine?

Who should get intradermal vs. subcutaneous dosing of JYNNEOS vaccine?

Public health jurisdictions and healthcare providers have the flexibility to offer the intradermal or subcutaneous regimen based on balancing optimal vaccine use and acceptance, feasibility of administration, and available vaccine supply. People of any age with a history of developing keloid scars and individuals younger than 18 years of age should receive the vaccine via the subcutaneous route. Please see current CDC guidance for more information. 

If a person declines intradermal administration and/or if intradermal administration poses a barrier to vaccination, it is acceptable to administer the vaccine subcutaneously.  

CDC recommends that health care providers have both subcutaneous and intradermal vaccine administration options available on site so that those unable or unwilling to receive the intradermal regimen can receive the subcutaneous regimen if desired.

How do I administer JYNNEOS vaccine intradermally?

JYNNEOS vaccine can be administered through intradermal (ID) injection for people ages 18 years and older. The authorized alternative regimen involves an injection volume of 0.1mL.

For specific technical guidance related to mpox vaccine, please refer to the EZIZ Mpox page. This page includes links to CDC mpox vaccine clinical guidance, storage and handling, and vaccine administration details. A video on intradermal tec​hnique can be found he​re.

Where on the body should JYNNEOS vaccine be administered intradermally? 

When administering JYNNEOS vaccine, the preferred location is the volar (inner aspect) of the forearm. If administration in the forearm is a barrier to vaccination, JYNNEOS can be given intradermally below the scapula or over the deltoid.

What about tattoos?

Intradermal administration of JYNNEOS in the setting of tattoos is possible however it is advised to avoid tattoos that are less than 1 month old and avoid pigmented areas of older tattoos.

What kind of syringes should be used for intradermal administration?

The intradermal dosing regimen supported through the Emergency Use Authorization does not specify a syringe/needle type and thus, any commercially available needle/syringe combination that would allow intradermal use would be acceptable. CDC administration guidance currently mentions use of a 26- or 27- gauge x 3/8", 1/4" to 1/2" needle with a short bevel as an example and not a requirement.

Can immunocompromised persons receive JYNNEOS vaccine intradermally? 

Yes, immunocompromised persons who are aged 18 years and older and who do not have a history of keloid can receive the JYNNEOS vaccine intradermally.   

How do I administer JYNNEOS vaccine subcutaneously?

The standard regimen involves a subcutaneous (SC) route of administration with an injection volume of 0.5mL. The standard regimen has been approved for people aged 18 years and older, as well as authorized for people aged less than 18 years under an Emergency Use Authorization.

Is there a lower age limit for JYNNEOS vaccine?

There is currently no established lower age limit for JYNNEOS vaccine.


What are major reporting requirements for providers who administer JYNNEOS vaccine?

Providers should report doses to their immunization registry within 24 hours of vaccine administration.

Where should providers report adverse events following vaccination?

Adverse events that occur in a recipient following mpox vaccination should be reported to the Vaccine Adverse Event Reporting System (VAERS). Reporting is encouraged for any clinically significant adverse event, even if it is uncertain whether the vaccine caused the event. Vaccine administration errors can be reported whether or not associated with an adverse event. Information on how to submit a report to VAERS is available at VAERS Site or by calling 1-800-822-7967.

Where should patients report adverse events following vaccination?

Adverse events that occur in a recipient following mpox vaccination should be reported to V-safe. Reporting is encouraged for any clinically significant adverse event, even if it is uncertain whether the vaccine caused the event. Information on how to submit a report is available at the V-safe website or by calling 1- 800-232-4636

Billing & Reimbursement

Where can JYNNEOS vaccine providers find current information and resources on vaccine billing and reimbursement?

Providers can refer to following resources:

Can providers bill for JYNNEOS vaccine?

There would be no cost for the vaccine itself as it is provided by the United States Government. Providers may charge an associated administration fee (or facility fees). Providers should bill for Mpox vaccine administration using the same processes they use for other routine vaccines, like Tdap and MMR. 

  • Providers can use the ICD-10 Z code, "Z23 Encounter for immunization," and they could consider offering MenACWY or other recommended vaccines at the same time and bill for them concurrently.
  • ICD-10 codes should be available for Orthopoxvirus infections.

Communication Resources

Where can I stay informed on mpox vaccine information?

The CDPH Mpox Page has information for the public, providers, and local health department. For specific technical guidance related to mpox vaccine, please refer to the EZIZ Mpox page.

Where can I access mpox vaccination data dashboards?

The CDPH Mpox Page and the CDPH Mpox Data page has information on mpox vaccine allocations and other mpox data.

Additional Resources

[1] It may be reasonable to consider PEP for certain exposures >14 days prior, such as high-risk exposure in a high-risk person at high risk for severe disease. (Communication with Dr. Brett Petersen, CDC, 5/27/22)

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