Document text
National Center for Emerging and Zoonotic Infectious Diseases
Use of JYNNEOS During Mpox Outbreaks: Clinical
Guidance
Agam Rao, MD
CAPT, US Public Health Service
Medical Officer
Poxvirus and Rabies Branch
Advisory Committee on Immunization Practices
June 23, 2023
Vote passed during February 2023 ACIP meeting
ACIP recommends the 2 -dose* JYNNEOS vaccine series for persons
aged 18 years and older at risk of mpox during an mpox outbreak§
*Dose 2 administered one month after dose 1
§ Public health authorities determine whether there is an mpox outbreak; a single case may be considered
an mpox outbreak at the discretion of public health authorities. Other circumstances in which a public
health response may be indicated include ongoing risk of introduction of mpox into a community due to
disease activity in another geographic area.
Vaccination with JYNNEOS is a 2 -dose series
▪Post -exposure: Concerning exposure should trigger consideration for
vaccination regardless of where the exposure occurs (e.g., healthcare
setting vs. community)
▪Pre-exposure: Whether specific populations (e.g., children, pregnant
persons) should receive vaccinations is dependent on the risk during a
specific outbreak
▪Goal of clinical guidance: Provide general information that can inform
decision -making for specific mpox outbreaks
Clinical guidance
▪Vaccinating at -risk populations during an outbreak
– Persons <18 years of age
– Pregnant persons
– Breastfeeding persons
▪Vaccinating HCP and certain laboratorians during an outbreak
– Healthcare personnel (HCP)
– Certain laboratorians
▪Administration guidance
– Coadministration with COVID -19 vaccines
– Immunoglobulin products
– Other guidance
Vaccinating at -risk populations during an
mpox outbreak
Mpox in persons <18 years of age, 1970 -2022
▪Central and West Africa, Clades I (n= <1638*) and IIa (n= 6)
–
–
–
–
– 1970 -1985: Increased incidence and severity in children ≤ 8 years of age
compared to adolescents and adults, likely because younger children had not
been routinely vaccinated to prevent smallpox
2006 -2015: No difference in incidence or severity in children compared to
adults, likely reflecting cessation of childhood smallpox vaccinations among
persons who were adults at the time of evaluations
▪United States and United Kingdom, Clades IIa (n= 12) and IIb (n= 125)
2 children hospitalized during 2003 U.S. outbreak and 1 child hospitalized during
2021 in United Kingdom; all recovered
No severe manifestations among U.S. children during current outbreak
Severe manifestation reported among a neonate in UK (adenovirus co -infection)
*Includes 18 –19-year -olds from the Democratic Republic of the Congo
Use of JYNNEOS in persons aged <18 years
▪
▪
▪12-17 years of age, n=349
• No safety signals identified via CDC surveillance systems
• No efficacy data from pre-licensure trials
• Unable to evaluate real-world VE during current outbreak
U.S. JYNNEOS first doses§
administered to pediatric patients by
age and gender
girl
boy
• NIH clinical trial underway to evaluate safety and efficacy
0-11 years of age, n=377
• No safety signals identified via CDC surveillance systems
• No efficacy data from pre-licensure trials
• Unable to evaluate real-world VE during current outbreak
• Concerns that dose may be different for those in the
younger ages
• No clinical trials or other studies planned at this time
Data from recent publication* is encouraging § Fewer children received 2 doses (compared
to 1 dose); CDC unpublished data (does not
include data from one state)
* Ladhani et al. Lancet In fect Dis. 20 23
Clinical guidance for children and adolescents
▪For persons 6 months -17 years, JYNNEOS should be administered as PrEP or PEP
(as indicated by public health authorities for a specific outbreak) if a high -risk
exposure has occurred
–
–
– For younger children (e.g., <6 years of age), clinicians should be aware that no studies involving
JYNNEOS have been performed to determine appropriate dose
Decisions about vaccination with JYNNEOS should involve risk/benefit assessment for every
pediatric age group during a specific outbreak
After completion of ongoing clinical trial, ACIP may consider a vote re: use of JYNNEOS in
children 12 -17 years of age during mpox outbreaks
▪For children < 6 months of age, VIGIV should be administered in lieu of JYNNEOS if
PEP is indicated
Detection and transmission of MPXV during the
current outbreak
* DNA has been detected at Ct values <35 in recovered patients more than 30 days after illness onset in an upper respiratory tract swab, saliva, and semen.
† The preponderance of existing data support exposure to anorectal and vulvovaginal tissues and fluids as capable of transmit ting infection; however, it is difficult with current evidence to definitively isolate these exposures
from other concomitant exposures (see text).
‡ Includes body modification with piercings and tattooing.
https://www.cdc.gov/poxvirus/monkeypox/about/science -behind -transmission.html
Mpox in pregnant persons
▪Historically*
–
–
–
– Mpox known to have been transmitted pre and perinatally to at least 2
neonates
Neonatal outcomes among neonates born to mothers who had mpox
(n=5) included a stillbirth, self -limited rash, and healthy neonates
▪During 2022/2023 U.S. outbreak
Outcomes among pregnant women are being evaluated
Transmission to neonate known to have occurred
*This information is limited to published reports
from countries where MPXV is endemic
Use of JYNNEOS in pregnant persons
▪Unknown if JYNNEOS administered to pregnant persons during 2022/2023
outbreak
▪No adverse events (passively reported via VAERS) have been received
▪2022 ACIP recommendations for persons at risk for occupational exposure
explicitly states JYNNEOS not contraindicated in pregnant persons
Mpox spread during breastfeeding and use of
JYNNEOS among breastfeeding persons*
▪Mpox known to be transmitted when child exposed to mpox skin lesions
(e.g., under breast)
▪Mpox not known to be transmitted via breast milk; for one patient during
2022 outbreak, breast milk samples negative for MPXV DNA by PCR
▪No information about whether breast -feeding persons received JYNNEOS
during ongoing outbreak; however, no VAERS reports were received that
mentioned breast -feeding persons
*https://www.cdc.gov/mmwr/volumes/72/wr/mm7201a2.htm?s_cid=mm7201a2_w
Proposed clinical guidance for pregnant and breastfeeding persons
▪JYNNEOS not contraindicated in persons who are pregnant or breastfeeding
▪Available human data insufficient to determine vaccine -associated risks in
pregnancy. However, animal models including rats and rabbits have shown no
evidence of harm to developing fetus
▪Safety and efficacy of JYNNEOS not been evaluated in breastfeeding women. It is
not definitively known whether JYNNEOS is excreted in human milk. Data are not
available to assess the impact of JYNNEOS on milk production or the safety of
JYNNEOS in breastfed infants. However, because JYNNEOS vaccine is replication -
deficient, it likely does not present a risk of transmission to breastfed infants and
can be administered to women who are breastfeeding after weighing the benefits
and harms
▪If high -risk exposures cannot be avoided or have already occurred, persons who are
pregnant or breastfeeding may receive JYNNEOS
Vaccinating HCP and certain laboratorians
during an mpox outbreak
Mpox acquired via laboratory or healthcare exposures
▪2022/2023 U.S. mpox outbreak
– Laboratory personnel: No reports
– HCP: 23 potential exposures
• Most associated with sharps injuries while attempting to unroof, open, or
aspirate mpox lesions*
• Some associated with suboptimal PPE use
▪Historical data from endemic countries
– Laboratory personnel: No data
– HCP: Acquired providing care to family members/friends in homes or with
little PPE
*Unroofing or aspirating lesions is discouraged https://www.cdc.gov/poxvirus/mpox/clinicians/prep -
collection -specimens.html
Detection and transmission of MPXV during the
current outbreak
* DNA has been detected at Ct values <35 in recovered patients more than 30 days after illness onset in an upper respiratory tract swab, saliva, and semen.
† The preponderance of existing data support exposure to anorectal and vulvovaginal tissues and fluids as capable of transmit ting infection; however, it is difficult with current evidence to definitively isolate these exposures
from other concomitant exposures (see text).
‡ Includes body modification with piercings and tattooing.
https://www.cdc.gov/poxvirus/monkeypox/about/science -behind -transmission.html
Use of JYNNEOS for preexposure vaccination of persons at risk for
occupational exposure to orthopoxviruses : Recommendations of the
ACIP—United States, 2022
▪For research laboratory personnel* and clinical laboratory personnel
performing diagnostic testing for orthopoxviruses§, ACIP recommends use
of JYNNEOS for primary vaccination as an alternative to ACAM2000
▪For healthcare personnel who administer ACAM2000 or care for patients
infected with orthopoxviruses , ACIP recommends use of JYNNEOS (as an
alternative to ACAM2000) based on shared clinical decision -making
*Research laboratory personnel are those who directly handle cultures or animals contaminated or infected with replication -compe tent vaccinia virus,
recombinant vaccinia viruses derived from replication -competent vaccinia strains (i.e., those that are capable of causing clinic al infection and producing
infectious virus in humans), or other orthopoxviruses that infect humans (e.g., Monkeypox virus, Cowpox virus, and Variola virus)
§Clinical laboratory personnel who perform routine chemistry, hematology, and urinalysis testing, including for patients with suspected or confirmed
orthopoxvirus infections, are not included in this recommendation because their risk for exposure is low
Pre-exposure prophylaxis: Use of JYNNEOS during
mpox outbreaks
▪For research laboratory personnel* and clinical laboratory personnel performing
diagnostic testing for mpox§, ACIP recommends use of JYNNEOS for pre-exposure
vaccination as an alternative to ACAM2000
▪For clinical laboratory personnel who handle specimens that may have a higher
possibility of containing replication competent MPXV (e.g., lesion material, throat
swabs, oral swabs, rectal swabs), and certain healthcare personnel who care for
patients infected with mpox or administer ACAM2000 §, ACIP recommends use of
JYNNEOS (as an alternative to ACAM2000) based on shared clinical decision -making
*Research laboratory personnel are those who directly handle cultures or animals contaminated or infected with monkeypox viru s (MPXV)
§Vaccination is not routinely recommended for clinical laboratory personnel who perform routine chemistry, hematology, and urinalysis testing,
including for patients with suspected or confirmed MPXV infection , healthcare personnel who care for patients with mpox or administer ACAM2000.
Recommended infection prevention and control practices are effective in minimizing transmission. Vaccination can be offered b ased on site -and
activity -specific biosafety risk assessments (e.g., identification of laboratory procedures with a high likelihood of generatin g aerosols or inadequate PPE
availability)
Administration guidance
Coadministration of JYNNEOS with COVID -19 vaccines
▪There is no required minimum interval between receiving any COVID -19 vaccine
and JYNNEOS vaccine (e.g., for mpox prevention), regardless of which vaccine is
administered first
▪People, particularly adolescent and young adult males, who are recommended to
receive both vaccines might consider waiting 4 weeks between vaccines. This is
because of the observed risk for myocarditis and pericarditis after receipt of
ACAM2000 orthopoxvirus vaccine and COVID -19 vaccines and the hypothetical risk
for myocarditis and pericarditis after JYNNEOS vaccine. However, if a patient’s risk
for mpox or severe disease due to COVID -19 is increased, administration of
JYNNEOS and COVID -19 vaccines should not be delayed
Implications of JYNNEOS administration in close
temporal proximity to immunoglobulin products
▪Antibodies to measles and varicella high in immune globulin products;
administration of these in close temporal proximity can prevent the
vaccine from entering cells and being effective
▪Antibodies to orthopoxviruses are believed to be low in most immune
globulin products (e.g., IVIG) and will likely remain low in the future
▪Antibodies to orthopoxviruses are present in VIGIV (purified
immunoglobulin from persons vaccinated against smallpox); however,
whether these could prevent the vaccine from being effective is unknown
Clinical guidance when JYNNEOS and immunoglobulin
products are temporally administered
▪Most immunoglobulin products: No precautions are necessary if JYNNEOS
is administered in close temporal proximity to IVIG
▪VIGIV
– VIGIV could interfere with immune response to JYNNEOS
• Ideally, administration of JYNNEOS should be delayed if VIGIV was recently administered
• The duration for which it should be delayed is unknown; during outbreaks, it is acceptable
to administer a dose of JYNNEOS; however, public health consultation should be obtained
for case specific guidance about an additional dose at a later time
– Unlikely that VIGIV would be administered in close proximity to JYNNEOS
Other administration guidance
▪Unintentional delays do not require restarting the series; the second dose
should be administered as soon as possible even if >1 year has elapsed
▪In settings where subcutaneous administration is not preferred (e.g.,
vaccine is in short supply), the vaccine can be administered intradermally
▪In settings where intradermal administration is not possible (e.g., because
staff are not trained or uncomfortable)
– Jurisdictions may administer subcutaneous vaccinations and prioritize first doses of the 2 -dose
JYNNEOS series
– Second doses should be administered as soon as vaccine availability allows
▪Decisions about vaccine administration should ensure equitable
distribution of vaccine doses
Acknowledgements
▪Faisal Minhaj ▪Amanda Cohn
▪Jim Campbell ▪Melinda Wharton
▪Jafar Razeq ▪Manisha (Mo) Patel
▪Mark Russi ▪Paul Rota
▪Howard Minkoff ▪Rosalind Carter
▪Sathesh Panayampalli ▪Catherine McLean
▪Christina Hutson ▪Jonathan Duffy
▪David Kuhar ▪Ian Kracalik
▪Marie de Perio ▪Leora Feldstein
▪John Brooks ▪Andrea McCollum ▪ACIP Mpox WG
▪Sara Oliver
▪Tara Anderson
▪Evelyn Twentyman
▪Allie Tuttle
▪AAP’s COID and
Redbook
Questions?
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY: 1 -888-232-6348 www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the
official position of the Centers for Disease Control and Prevention.
National Center for Emerging and Zoonotic Infectious Diseases
Division of High -Consequence Pathogens and Pathology