7 July 2022 Episode 272 Monkeypox MPX clade 3 update

Thu, 07/07/2022 - 17:39

Episode 272 Monkeypox (MPX clade 3) update

Dear colleagues,

Please find herewith some recent comments, papers and preprints with down-to-earth information.

Ep 271: Three science journalist comments

  1. Max Kozlov in Nature Briefing asks attention for the ignored monkeypox epidemic in Africa with each years thousands of cases and probably a 10 % fatality rate in Central Africa.  No access to vaccination, despite recurrent inquiries !  
  2. Kai Kupferschmidt in Science Insider comments and criticizes the WHO decision NOT to declare the present epidemic as a Public Health Emergency of International Concern (PHEIC).
  3. Kai Kupferschmidt again in Science Insider discussed the MSM nature of the present outbreak, with a subgroup of dense sexual networks at the core of the rapid spread
  4. CDC is more cautious and leaves the possibility open of other transmission pathways: Monkeypox spreads in different ways:
  • direct contact with the infectious rash, scabs, or body fluids
  • respiratory secretions during prolonged, face-to-face contact, or during intimate physical contact, such as kissing, cuddling, or sex
  • touching items (such as clothing or linens) that previously touched the infectious rash or body fluids
  • pregnant people can spread the virus to their fetus through the placenta


It’s also possible for people to get monkeypox from infected animals, either by being scratched or bitten by the animal or by preparing or eating meat or using products from an infected animal.


Monkeypox can spread from the time symptoms start until the rash has fully healed and a fresh layer of skin has formed. The illness typically lasts 2-4 weeks. People who do not have monkeypox symptoms cannot spread the virus to others. At this time, it is not known if monkeypox can spread through semen or vaginal fluids.  

Note: with regard to these statements see Ep 272-5



Ep 272-2 A:  Girometti Lancet Infect Dis 1 July: Observational study in STD clinic in London on 54 symptomatic cases:  

  • All were MSM; a quarter were HIV(+) and also a quarter had an STI;
  • Pre-eruptive phase with fever, asthenia, lethargy, sore throat, myalgia
  • All had skin lesions of which 94 % involved the ano-genital area and 7 % oro-pharyngeal
  • 30 % lymphadenopathy
  • Five were hospitalized for pain or bacterial sur-infection, but none died.  


Ep 272-2 B: Comments by Zachariou in BMJ

It is possible that at various stages of the infection monkeypox may mimic common STI, such as herpes and syphilis, in its presentation.


Ep 272-3:  Charniga medRxiv 23 June Incubation time  


Based on 40 cases mean incubation period from exposure to first symptom onset

7.6 days  with the upper 95th percentile was 17.1 days (credibility interval: 12.7–24.3).


These findings align with current CDC recommendations for monitoring close contacts of people with monkeypox for 21 days after their last exposure.


Ep 273-4: Badenoc medRxiv 5 July: Meta-analysis on the evidence of neurological and psychiatric complications of MPX.

  • Commonly reported and nonspecific neurological symptoms (myalgia and headache)
  • Also rarer but more severe neurological complications, such as encephalitis and seizures.


Less evidence regarding the psychiatric sequelae of monkeypox: multiple reports of anxiety and depression but  the prevalence of these symptoms is unknown.


Higher quality research = needed


Ep 272-5: De Baetselier medRxiv 5 July 2022: Asymptomatic MPX infections among male sexual health clinic attendees.


Four positive MPX DNA amongst 224 anorectal and oropharyngeal swabs from men collected for gonorrhoea/chlamydia screening during May 2022, with no MPX symptoms



  • MPX virus might be transmitted to close contacts in the absence of symptoms.
  • Identification and isolation of symptomatic individuals may not suffice to contain the outbreak.




Ep 272-6 A: Petersen ICID 5 July: Proposed indication for vaccination against MPX clade 3


Two types of vaccine available:

  1. JYNNEOS®/IMVANEX®, (see Ep 272-6 B)  = live vaccine produced from the Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) strain, an attenuated, non-replicating orthopoxvirus manufactured by Bavarian Nordic, Hellerup, Denmark

Two doses sub-cutaneously 4 weeks apart  

This is a safe vaccine: only mild-moderate local and systemic side effects (see


  1. ACAM2000® (IMVAMUNE®) (Ep 272-6 C) = replication competent vaccinia virus, belonging to the poxvirus family and is manufactured by Emergent BioSolutions Inc. Gaithersburg US:

Usually one dose per-cutaneously (scratch)

  • May cause rash, fever, and head and body aches.
  • Particularly those who are immunocompromised and who have eczema and atopic dermatitis, complications from the vaccinia virus can be severe and person-to-person

spread of the vaccinia vaccine virus can occur

  • Various other rare but serious side effects: myocarditis/pericarditis; Stevens-Johnson; vaccinia blindness etc


Clearly, IMVANEX is preferred to prevent a non-lethal infection with MPX


Post-exposure prophylaxis: should be offered to contacts of cases within four days after exposure


Pre-exposure prophylaxis:

  1. Health workers at risk, including clinical and laboratory workers who are in contact with patient material.  = INDICATED
  2. Should  a vaccine be recommended  to MSM who self-identify as having multiple partners or to those who are already under treatment for other STDs, such as HIV, syphilis, gonorrhoea?

 → The authors feel that it is NOT systematically indicated and that we need a randomized controlled study (with another vaccine in the control arm).  


Ep 272-6 D:  In view of present shortage: one dose of IMVANEX should suffice (to be completed after 1-2 years).




Ep 272-7 A: Nörz in Eurosurvaillance July 2022 is warning that MPX can contaminate surfaces in rooms occupied by MPX patients


Contamination with up to 10exp5 viral copies/cm2 on inanimate surfaces was estimated by PCR and the virus was successfully isolated from surfaces with more than 10exp6 copies


Ep 272-7 B: Kampf in J Hosp Infect July 2022


Most regular decontaminants can reduce MPX by > 10 exp 4

  • 70% ethanol (≤ 1 min), 0.2% peracetic acid (≤ 10 min) and 1%-10% of a probiotic cleaner (1h),
  • Hydrogen peroxide (14.4%) and iodine (0.04% -1%)
  • Sodium hypochlorite (0.25% - 2.5%; 1 min), 2% glutaraldehyde (10 min) and 0.55% ortho-phthalaldehyde (5 min)




  1. African epidemics have been neglected for 40 years
  2. Present epidemic mainly in MSM, but various other transmission pathways still possible
  3. Genital lesions prominent in MSM, often with HOV or other STI; neurological and psychiatric symptoms possible, but more research needed
  4. Mean incubation time = 1 week, but maybe up to 3 weeks
  5. Virus found in anorectal swabs of men visiting STI clinic, but without MPX symptoms: asymptomatic transmission possible?
  6. Pre- and post-exposure vaccination with 1 (or 2 doses) IMVANEX
  7. Contamination of surfaces can be neutralized with regular disinfectants.


Hope this was useful