Towards a #MERS Vaccine? Who is the target?

Helen Branswell has recently published Camel vaccine against MERS could slow human to camel infections.

In its 10th meeting hold on september 3rd, IHR Emergency Committee of WHO addressed a couple of things related to vaccine:

WHO Statement on 10th meeting IHR/EC

  • International collaboration to develop human and animal vaccines and therapeutics should be accelerated.

Laboratories have launched their battle-field researchers in order to be the first to produce a vaccine against MERS; whatever the vaccine would be?

Mers-virus-3D-image

Since 2012, Virology and Epidemiology have brought on the table a lot of information about the virus itself, a coronavirus, same family of SARS virus.

As of today we know how MERS is operating as an infectious disease, hosted by dromadary camels mainly in Middle-East (>90% infected), starting by a zoonosis then spreading human to human through clusters in household or nosocomial infection in the hospitals.

Two kinds of infected (by Mers-Cov) population have emerged in KSA:

  • symptomatic:either elderly or People with underlying poor medical conditions or chronic diseases including but not limited to diabetes,chronic renal failure, cardio-respiratory diseases or immunosuppressed
  • asymptomatic:healthy carriers

Root causes,mitigations and prevention of MERS-CoV_2015

Identifying healthy carriers, asymptomatic ones is based on positive testing, sometimes in link with health risks exposure like camels herds owners, slaughterhouse workers, or health care workers (HCW). Even if prevalence is quite low, we have identified a life cycle for Mers infection and outbreaks (see chart).

It is not the purpose here to review the conditions for nosocomial outbreak at the hospitals; see: Follow-up of the nosocomial #MERS outbreak in Riyadh,KSA

Knowing that, how could we prevent MERS from spreading both at community hospital level and at household level? Would it be realistic to vaccine the entire KSA population or only People at high risks? Would such a vaccination program prevent actually MERS from spreading?

Or do we focus on the source of MERS Coronavirus, I mean dromadary camels and manly young calves under 5 years old? It would make more sense with a long lasting and sustainable outcome to prevent Mers coronavirus from jumping outside of animal to human; in other words to prevent a zoonosis?

The answer seems obviously understood in the question…KSA MOH is supporting and sponsoring the idea of an animal vaccine by working hard on this issue.

Comprehensive understanding of nosocomial #MERS outbreaks

Since 2014, we assist a continuous spread of MERS outbreak, moslty occuring in medical facilities.

After South Korea (SK), turn back to KSA and Riyadh main hospital facility where an ongoing nosocomial outbreak is occurring . It is not a matter of means or competency , it seems to be more related to a management system of the emergencies.Jeddah emergency ward

Recent lessons learned from SK demonstrate that MERS spread risk factors are related to overcrowded rooms, lack of air-conditioning and/or contaminated air filters, very long wait.

Today, it might be interesting for a better understanding of the root causes, to follow the “patient path” and address time and space issues from arrival/admittance at the hospital till hospitalization or release.

overcrowded ER

Who is the first health care worker (HCW) and position allowed and able to take care of a suspicious infected person?

How is this HCW protected? Are standard precautions (gloves, facial masks,coverall,glasses) implemented and applied? As a minimum, any new case arriving at ER would have to wear a facial mask and hand sanitizing…

The second point to raise is the best practice for sorting People who are admitted at the ER and based on which criteria:

  • suspicious case of infection with fever?
  • complication or illness related to an underlying medical condition (diabetes,renal failure,respiratory failure,…)?
  • or both?

Behind this first “gate control”, then a split between infected/non infected based on symptomatic/asymptomatic cases would lead to decision for isolating/quarantine and waiting for further investigation and testing.  Any positive test for MERS-CoV would trigger a track of contacts.

We know that MERS-CoV is not an easy spreading virus from human to human, but, under certain circumstances like close contacts in confined space could be responsible for contamination either to relatives, other hospitalized People or even worse, HCW if unprotected.

Regarding architecture of buildings where emergency wards are installed, it is important to address the impact assessment of contamination risk depending of both vertical and horizontal positions. With regards to this specific issue, it is amazing to look back in the past, when residential hospital model, in early XX° century, was built to prevent infectious diseases from spreading indoor and outdoor. Nowadays, we are focusing more  on air conditioned tower and its risk of Legionella or on air filters like for MERS Coronavirus in SK.

The new architecture of hospitals is more (internal and external) customer orientated, developing easy access through corridors or lifts, gangways and subways in order to facilitate communication and transfer of patients but also and by the way, facilitating the spread of virus and bacteria…except in restricted areas like operating room, ICU where specific procedures are in force.

nosocomial risk assessment

Unfortunately, HCW are not champion for hand hygiene and sanitation, especially during care management by passing from one patient to another without applying mandatory process for decontamination.

Now, we have all we need to have to understand the occurence of a nosocomial MERS outbreak. An Hazard analysis critical control point would prevent from a cross-contamination by regulating the flow of patients arriving and staying in ER.

Another lesson learned from avian Flu H1N1 pandemics is to inform suspected infected patients and for asymptomatic ones to prevent from coming to ER; putting in place a phone call number like 911 in case of an emergency and to organize a safe and secured ground transportation by ambulance driven by protected and trained paramedics.

Patients and their relatives or visitors would be aware about the health risks related from getting MERS; they could become vector of the coronavirus. So, hygiene measures including hand sanitation and cough etiquette are of great importance and must be highlighted by Health authorities.