COVID-19 is still going strong, far outstripping my lame intentions to post something weekly. I have been keeping close tabs on all developments, but I feel like I would need to post a few times a week to be useful and I can't seem to make time for that. I do hope to give a COVID-19 summary update at the next Montgomery County Pediatric Society virtual meeting on March 8. In the meantime if you have particular questions please use the Comments section to pose them.
This week the news media finally seemed to start paying attention to disturbing developments in Ebola virus infections in both East and West Africa. It's worth discussion, especially since the world is much better prepared to handle it now than it was during the large outbreak in West Africa a few years ago.
First to East Africa, where we have new cases appearing in the Democratic Republic of Congo. The total number of cases is low, perhaps 6 (it's difficult to be certain of the exact number mostly based on media reports), but what is noteworthy is that the index case may have been infected by semen from an Ebola survivor originally infected in the 2018-20 outbreak in the DRC. Fortunately public health resources are being mobilized rapidly in a locale which like many other countries previously has had significant barriers to public health measures for Ebola control.
In West Africa, Guinea is the epicenter of a new outbreak. This was one of the countries, along with Liberia and Sierra Leone, most affected by the 2014-16 outbreak that spilled over into the US and elsewhere. Here the index case appears to be a nurse who first sought medical attention on January 18, was misdiagnosed for a time, and ultimately died on January 28. She was buried without safety protocols, further exposing others to the virus. As in the DRC, public health interventions are proceeding much more rapidly than in the past. As I write this, the World Health Organization is deploying staff to the area, along with millions of dollars in funding. Importantly, we have 2 main tools today that were not available in past outbreaks.
First, we now have specific treatment for Ebola virus disease in the form of a monoclonal antibody cocktail approved by the FDA a few months ago; results of a large trial were published in the NEJM in December. The trade name is Inmazeb, a bit less of a mouthful than the trio of monoclonal antibodies that make up the pharmaceutical: atoltivimab, maftivimab, and odesivimab-ebgn. It is effective in lessening mortality in infected individuals especially if given early in the disease course. Unfortunately it is administered IV so it is a little more cumbersome especially in resource-poor areas.
Second are Ebola vaccines. The US FDA approved one, called Ervebo, last December. It is a live recombinant vaccine made using a backbone of vesicular stomatitis virus (VSV) with the envelope glycoprotein of the Zaire ebolavirus substituted into the nucleic acid code. (VSV is primarily a disease of cattle, horses, and swine, and outbreaks have occurred in the US. Humans occasionally can be infected, primarily from direct contact with infected animals.) This vaccine is used to immunize contacts of Ebola virus patients in what is termed "ring vaccination;" the technique was highly successful in controlling and eventually eliminating smallpox, for example.
A second vaccine, not reviewed by the FDA, is available for use in other countries. It is actually a combination of 2 vaccines, a first dose Zabdeno which is an adenovirus-vector vaccine and a second dose called Mvabea which contains Vaccinia Ankara Bavarian Nordic virus supplemented with parts of various Ebola and related filoviruses. Because of the requirement for 2 doses, Zabdeno is not that helpful for immediate outbreak control such as with ring vaccination, but it is another tool to help contain the virus in a population.
The WHO announced creation of Ebola vaccine stockpiles just on January 12, 2021, good timing for what we are experiencing now. Immunization programs started in the DRC on February 15; vaccine shipments will arrive in Guinea on February 21 with vaccine campaigns starting on February 22.
Perhaps the US currently is at less risk for imported Ebola because of somewhat limited international travel, but we should not relax. Just as with SARS-CoV-2, any health crisis anywhere in the world affects all of us. Outbreaks in resource-poor populations can be devastating. I'm hopeful all the new advances in Ebola virus disease will prevent a repeat of the tragic 2014-16 West African outbreak.