It’s now been 7 years since the human species lost one of its fiercest weapons against the threat of infectious disease: D.A. Henderson. Each year, I assemble a list of questions that I wish I could just rattle off rapid fire as I walked into his office door as I used to have the distinct honor to do on a regular basis for 8 years. D.A., often wearing a sweater vest, would turn in his chair and indulge me while regaling me with some story of some thing that happened to him or related to whatever the subject of my question was. In the end, I often had the answer — sometimes DA would affirm my own thinking and other times he would point out a connection that I was not aware of and lead me to dive into the medical literature. I was recently looking through some old papers and spotted DA’s handwriting in the margins of a medical journal article alerting me to something he noted and wanted me to notice as well. It is his benevolence and his interest in cultivating my limitless quest to learn all I could about infectious disease that is what I miss most about him. Individuals infrequently get to sit in the presence of extreme competence and genius that it is hard to describe to those who have not experienced it themself.
Without further preamble, here’s what I would excitedly run into DA’s office to ask him if he were still here:
1. What do you think is happening with SARS-CoV-2 in terms of how quickly it will modulate to become more like the other 4 seasonal coronaviruses? It still is killing more than they do and mutating more than them. Will it take another couple of years? Less? What is the determining factor?
2. Is the biggest influenza pandemic threat the 2.3.4 clade of H5N1? The fact that it is prolifically spreading amongst avian species and infecting countless mammal species yet not been able to do much to humans is hard to integrate with it being the major pandemic threat from the influenza virus family.
3. Why didn’t smallpox vaccination hold up completely against mpox? Is it just waning immunity over time? What did you think of Jynneos — I know that you thought Dryvax/ACAM2000 was the vaccine of choice but Jynneos seemed to hold its own in preventing severe disease. Would you have selectively deployed the 1st generation vaccine?
4. It seems that polio eradication is completely fixated not on wild polio but on the vaccine-derived viruses, contrary to your advice to the eradication teams. It seems that chasing vaccine-derived strains has gone about the way you predicted it would. There is now even a novel oral polio type 2 vaccine — more genetically stable and therefore less likely to cause paralytic disease — which itself has caused paralysis? How would you now convince the polio eradicators to focus on wild polio?
5. What is behind the successive Ebola Sudan and Marburg outbreaks? Some occurring in countries that are not known to be major filovirus epicenters? Is it the reservoir host’s migratory patterns? Is it that better diagnostics have made more undifferentiated illnesses identifiable?
The way DA would provide answers to these 5 questions would be illuminating in a manner that has been sorely missing from the communicable disease world since his death. Each answer would undoubtedly provide a guide to the best policy prescription, adding to the resiliency of our species.
It is minds like DA’s that beat back the forces of a sometimes-inhospitable planet and for that we should all be thankful and hold out hope that another as independent and probing a mind arises and relishes tackling these problems in the manner of DA.