As some readers of this newsletter may sense, I give some thought to possible titles of my articles. Most non-fiction writers do or, at least, should take their pieces’ titles seriously. What are the criteria for a good title? There are two, I think. First, it should give at least a hint of the subject of the piece. After all, not every potential reader will want to invest the time to find out what the topic is by first reading the whole article. Second, a good title catches the reader’s attention by suggesting that it will be interesting, perhaps sometimes fun, at least that it will say something unexpected, even significant. Of course, an appealing title obliges the author to deliver a good piece, not a boring one.
I hope that my title, above, has caught your interest. In 2025, everyone over 10-12 knows what pandemics are, since we went through one between 2020 and 2022/23, and will have a sense of their importance for human societies. Furthermore, many older readers will catch the reference in the title to a book first published in 1963. That book was by the gifted Afro-American writer James Baldwin and was titled The Fire Next Time. It was about how anti-black racism had poisoned American society for centuries, for whites as well as black people, and it was meant to serve as a warning for America that this problem, if not attended to, would continue to have that effect.
A pandemic disease, especially one that has not yet taken place, is clearly a very different kind of problem from the phenomenon of racism, a persistent long-standing condition. However, once one accepts that the extent and severity of a pandemic will be greatly influenced by the pre-existing condition of the societies, in several key respects, the difference begins to diminish. If various factors can influence how bad or long a pandemic will be, then, in principle, steps can be taken in advance to ameliorate those effects by modifying the causative factors. In his book. Baldwin did not lay out a detailed program for reducing racism or its effects but his warning was prescient. His book was published just as the civil rights movement in America, which was focused on voting rights, was beginning to gather strength. However, the late ‘60s saw a small wave of urban riots by black Americans, who increasingly saw that increased accessibility to the vote in the South had done little or nothing to address the problems of black people in the North. Martin Luther King, Jr., assassinated in 1968, had been emphasizing this point for several years in his public statements. The fire next time, indeed; it had arrived a few years after Baldwin’s book had appeared.
As for the next pandemic, should we be thinking about it, having just barely recovered from COVID-19? Most public health officials would say “yes”. It is a virtual statistical certainty that there will be another because the conditions are right for it. Also, please remember, that we have had two in the last 40+ years. First, there was the AIDS pandemic of the late 1980s, then COVID-19. There had also been a couple of near-misses, the Ebola epidemic in Africa, which was handled and curtailed with some very fast and intelligent management, and SARS-1, in the early 2000s, involving a virus related to that causing COVID-19. (The failure of SARS-1 to become a true pandemic is something of a mystery, at least to me). Still, the existence of two unquestionable pandemics in about 40 years should give all of us reason for concern that there will probably be another pandemic in the not-so-distant future. Will we be ready for it?
I mentioned that the conditions favoring pandemics are already in place. Let me mention several. A pandemic is considered to be such when the disease agent begins to be rapidly transferred from human to human. A highly infectious agent, bacterial or viral, and close proximity of people to each other, from within small groups such as families to much larger social units, such as towns or cities, is usually enough to produce this condition. Before this stage, however, there is often a long prior stage in which the infectious agent circulates in one or more animal species, often without marked pathogenicity but sometimes causing illness or death but which was not detected by human observers, especially if the carrier animal species was wild. This relatively “silent” period ends if and when the infectious agent is transferred to humans, causes visible illness, and is readily infectious. This process of movement from wild animals to humans is termed “spillover” or, to use the technical term, “zoonosis”. 1
It is believed for instance, on several grounds, that the AIDS virus, HIV, initially circulated at low levels, probably in a somewhat less pathogenic variant in wild chimpanzees in Africa for perhaps about a century before it spilled over into humans, probably through the ingestion of chimpanzee meat from hunted, but infected, chimpanzees, so called “bushmeat”. 2
However, wild animals are not the only source of pathogens with human pandemic potential. Domesticated animals, which exist in far greater numbers than any wild animal species, can also be a major reservoir, and source of, such pathogens. It is believed that SARS-1, which never went beyond epidemic status to become a pandemic, came from infected chickens.
A third major factor in the spread of pandemic pathogens is modern air travel. The rapid spread of the COVID-19 virus from China to Europe and North America in late 2019-early 2022 almost certainly involved air travellers who had picked up the virus but were asymptomatic at the time of their flights. Air travel is such a major feature and benefit of our civilization that it will never be abandoned nor, since all pathogens have an incubation period that can last days during which they are not causing visible symptoms, can the dangers of infected travellers be entirely eliminated, though precautions can reduce them.
In an ever more crowded world, with increased numbers of people and domestic animals, and probably of increased contacts between wild animals and people, the factors that lay the groundwork for a pandemic, are, if anything, increasing.
What can be done to reduce either the chances of a new pandemic starting or, at least, the force of its impact? Should the world treat such events as the equivalent of an Act of God, as it would have done in earlier times, against which we are powerless? Fortunately, the answer to that is a firm “no”. Measures that could make a big difference can and should be taken. What is unclear is whether they will be taken soon enough and how efficacious they will prove to be.
One action that might help, in principle, would be identifying likely viruses that might be involved. A problem in this respect is the sheer numbers of different viruses that exist that might have some pathogenic potential and some ability to spread from animals to humans. One estimate that I have seen of the numbers of kinds of viruses present in mammals and birds is on the order of 2 million. Of course, the a priori expectation is that a large proportion of these viruses are well-adapted to their hosts and would not have strong “zoonotic” potential. That is some consolation but not much given the unknowns.
Fortunately, much is known about many viruses and the factors that influence their zoonotic capacity. Clearly, if any of those with high spillover potential are identified in samples taken from infected persons in a new infectious outbreak, and if the identification is made early, often things can be done both to treat the patients and to limit the spread to new people. Even if the virus is new to biological science, most such would be clearly related in their RNA or DNA sequence to previously identified viruses – being in the same virus “family” – about whose disease potential something is already known, including information on treatment and how to reduce the spread of such viruses. That relatedness might in turn provide clues as to how to proceed.
An informative analysis of this kind was published in 2021 in a top American journal, the Proceedings of the National Academy of Sciences. It scored a total of 887 viruses from about half a million tissue samples from approximately 75,000 wild animals, for their risk potential in terms of 31 well known risk factors. (For a discussion of the idea of risk factors, see “Risk factors”: an introduction). They were then ranked as to probable dangerousness from the combined assessment of these factors and put in a data base named, appropriately, Spillover. Gratifyingly, the top 12 viruses, rated in this way, out of the top 50, were all known to have serious zoonotic and pathogenic potential. These particularly “bad actors” included Lassa virus, the COViD-19 virus (officially designated SARS-CoV-2), Nipah virus, and rabies, for all of which there is helpful information. This data-base will undoubtedly be a big help in identifying pathogenic viruses with the potential for causing pandemics in the future. 3
There is a chance, however, that we already know the viral agent of the next pandemic. This is the influenza virus known as H5N1, more commonly referred to as “bird ‘flu”. (For an earlier discussion of this virus and its potential for causing major disease, see Bird ‘flu?!, Mpox ?!! What next? ) This virus has been spreading amongst wild birds for many years now. It has spread amongst many different species around the world and has killed millions of wild birds.
Over the last three years, the virus also has been detected in domestic poultry, sometimes mild but frequently lethal to the chickens. One estimate of the number of infected chickens in the US alone is 175 million. That is less than 10% of the estimated number of domesticated chickens in the world but it is still a large number. It is now apparent that it is also spreading amongst domesticated cattle and that it can be transmitted from chickens and cattle to humans, though probably at a relatively low rate and most typically in a mild form. Human-to-human transmission has, so far, not been reported.
At this point, therefore, this disease does not look threatening to humanity, at least compared to the known influenza pandemics of the past, especially the most severe, that of 1918-1919, which is estimated to have killed 50 million people. Nevertheless, the speed of spread and the documented record of its zoonotic potential, amongst different wild birds, then amongst domesticated chickens and cattle and other animals (such as cats and raccoons) give serious grounds for concern. A letter to Science in the March 5th issue, signed by seven experts, is titled “Prepare now for a potential H5N1 pandemic”. That letter and its warning should reduce complacency about the problem. Remember, the genetic distance between a mild infectious virus and a deadly pathogenic one can be as small as one base pair in the genome of the virus. Given the numbers of the virus that can be produced in one infected person, the chances of such a mutation occurring are high. Of course, other factors come into play as to whether it becomes a serious pathogen but the potential for a pandemic developing from a previously mild disease is real. 4
Indeed, one can argue that the pandemic has already arrived. It is mostly affecting, so far, birds and cattle, but the species barriers are clearly porous, spillover from this virus is already occurring, and we simply do not know how close we are to a major health problem with this virus. Waiting until there are greatly increased numbers of very ill, or dead, humans does not seem like a particularly wise strategy.
Inevitably, with an issue of public health, one comes back to questions of policy and what would be the best policies to head off any new pandemic or, at least, limit its death toll. The letter to Science cited above is filled with recommendations and one can only hope that many of the proposed measures will be adopted.
Here, however, one comes to a fact that is both scary and sad. Instead of preparing to head off or at least limit the death toll from the next pandemic, the Trump administration is dismantling safeguards and, thereby, increasing the risks. The first Trump administration, to give credit where credit is due, did something excellent in 2020, when faced with the COVID-19 pandemic: they facilitated the rapid development of vaccines, their so called “Operation Warp Speed”, and thereby probably saved millions of lives.
However, a few years earlier, they had done something that went in the opposite direction. The Obama administration, in response to the Ebola epidemic, had developed a preparedness program for dealing with a future pandemic. The Trump administration never put its recommendations into effect, for reasons they never even tried to explain, and essentially cancelled it. The result was that the US was left flat-footed when COVID-19 hit in 2020. Furthermore, the second Trump administration is continuing along the same lines, which will undermine readiness to deal with the next pandemic and public health in general, again without anything resembling a rational explanation. These measures included: taking the US out of the WHO, ending thousands of research grants for various medical and health issues, firing the advisory board of the CDC, ending the avian ‘flu vaccination program, and more.
One can only hope that there is a return to sanity in terms of public health measures in the near future but this might take several years, during which the damage could be immense. This is rather a grim note upon which to end this essay but I cannot think of one that would be both cheerful and realistic. The pandemic next time? It may not be that far away.
For a good book on the spillover phenomenon, see Quammen, D. (2012). Spillover: Animal Infection and the Next Human Pandemic. New York: W.W. Norton and Co. This book correctly predicted that the next major pandemic would involve a coronavirus.
For a review that provides a history of HIV, see Sharp, P.M., and B.H. Hahn (2011). Origins of HiV and the AIDS pandemic. Cold Spring Harbor Perspect. Med. Doi: 10.1101/cshperspect.a0006841.
See Grange, Z.L et al. (2021). Ranking the risk o animal-to-human spillover for newly discovered viruses . Proc. Natll. Acad. Sci. USA, doi.org/10.1073/pnas2002324118
See J.L. Goodman et al. (2025). Letters: Prepare now for a potential H5N1 pandemic. Science 387: 1047. Doi.org/10.1126/science.adw3278.