By: Sairah Sheikh, PharmD Candidate c/o 2024

​              As Coronavirus Disease 2019 (COVID-19) cases started to decrease in the United States (US), many Americans breathed a sigh of relief. However, on May 17, 2022, fear of a new infectious disease struck the nation. The first case of the monkeypox outbreak in the US was reported in a person from Massachusetts.¹ As of February 2023, the Centers for Disease Control and Prevention (CDC) has documented over 30,000 cases in the US and over 85,000 cases globally.² Although monkeypox commonly occurs in central and western African countries, the US held approximately 35% of the world’s cases in 2022.²  

Monkeypox can spread through direct contact with monkeypox lesions, respiratory secretions, or objects (e.g., bedding) used by an infected individual.³ During the monkeypox outbreak in the US, the virus was primarily transmitted through sexual contact, including kissing, hugging, and vaginal, anal, and oral sex.³ Most of these cases were reported in gay, bisexual, and other men who have sex with men.⁴ As a result, monkeypox is commonly mislabeled as a sexually transmitted disease (STD), however, since the virus does not exclusively spread through sexual intercourse, it cannot be deemed as such.

The hallmark symptom of monkeypox is a rash consisting of contagious lesions, predominantly occurring on the face, hands, and feet. The rash evolves from macules to papules, vesicles, pustules, and crusts. Once the lesions heal, the person is no longer considered contagious.^5,6 Other common characteristics of monkeypox include having flu-like symptoms such as fever, chills, headache, muscle aches, exhaustion, sore throat, nasal congestion, and cough. Altogether, symptoms may last for 2 to 4 weeks.⁵ Fortunately, the death toll for monkeypox remains low; since May 2022, there have been 28 deaths linked to monkeypox in the US.²

Currently, there are no specific treatments for monkeypox, however, since monkeypox is a member of the orthopoxvirus genus, tecovirimat, a medication indicated for human smallpox disease, can be given to those at a higher risk of infection from monkeypox.^7,8 Tecovirimat inhibits orthopoxvirus VP37 protein, a protein found in all members of the orthopoxvirus genus.  Inhibition of the VP37 protein blocks its interaction with cellular Rab9 GTPase and TIP47. As a result, the virus is unable to form enveloped virions necessary for dissemination throughout the body.⁸

Additionally, there are two available vaccines for monkeypox: the JYNNEOS vaccine and the ACAM2000 vaccine.^9,10 Both can be used for the prevention of monkeypox, however, the ACAM2000 vaccine has been associated with more frequent side effects and is not recommended for those who are immunocompromised.⁹ The ACAM2000 vaccine is approved for patients 1 year of age and older. It is administered via percutaneous route, using a bifurcated needle to deliver a 0.0025 mL droplet of reconstituted vaccine as a single dose. Serious adverse effects include myocarditis, pericarditis, and vaccinia virus transmission.⁹

The JYNNEOS vaccine is given in two doses, administered 28 days apart.¹⁰  It is typically administered subcutaneously at a dose of 0.5 mL, but due to supply shortages, it can be given intradermally at a dose of 0.1 mL.¹⁰  The two routes of administration are interchangeable, meaning that if a patient received the vaccine subcutaneously for their first dose, they can get their second dose intradermally, and vice versa.¹⁰  The efficacy of both routes of administration are similar, however, local side effects such as hyperpigmentation, rash, or redness may be more severe with the intradermal vaccine, potentially persisting for several weeks to months.¹⁰  Other local side effects of the vaccine may include pruritus, edema, and pain. Systemic side effects may include myalgia, fatigue, headache, chills, nausea, and fever.¹⁰ 

  With the current monkeypox outbreak, the CDC reports that unvaccinated individuals have 14 times the risk of contracting the disease compared to those who are vaccinated.¹¹ The CDC recommends vaccination for those who had known or suspected exposure to monkeypox, had sexual intercourse in the past 6 months with a partner diagnosed with monkeypox, or are immunocompromised.¹² For the remaining patient population, it is important to provide education on risk factors and measures to be taken to reduce exposure to the virus. Doing so will help prevent a future uptick in cases, as well as ensuring that patients have the appropriate resources to stay safe from monkeypox.

References

1. Technical report 3: multi-national mpox outbreak, United States, 2022. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/cases-data/technical-report/report-3.html. Last Updated 01/06/2023.
2. 2022 outbreak cases and data. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/response/2022/index.html. Last Updated 02/01/2023.
3. How it spreads. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/if-sick/transmission.html. Last Updated 02/02/2023.
4. Prevention. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/prevention/index.html. Last Updated 10/19/2022.
5. Clinical recognition. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/clinicians/clinical-recognition.html. Last Updated 08/23/2022.
6. Monkeypox. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/monkeypox. Published 05/19/2022.
7. Patient’s guide to mpox treatment with tecovirimat (TPOXX). Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/if-sick/treatment.html. Last Updated 11/28/2022.
8. TPOXX (tecovirimat) [package insert]. Greenville, NC; Patheon Manufacturing Services LLC; Revised 05/01/2022.
9. ACAM2000 vaccine. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/interim-considerations/acam2000-vaccine.html. Last Updated 10/21/2022.
10. JYNNEOS vaccine. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/interim-considerations/jynneos-vaccine.html. Last Updated 12/22/2022.
11. Rates of mpox cases by vaccination status. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/cases-data/mpx-vaccine-effectiveness.html. Last Updated 12/08/2022.
12. Mpox Vaccination Basics. Centers for Disease Control and Prevention. https://www.cdc.gov/poxvirus/monkeypox/vaccines/index.html. Last Updated 01/31/2023.

Published by Rho Chi Post