Further to my recent posting on viruses (” ‘Holy Grail’ vaccines to combat influenza virus”, 25 August) a bacteriologist has replied to me privately via an “All is Status” reader that I was amiss in writing about “weak” . . . immune systems and “gaps” within them. He is quite right in a technical sense, but they were terms it was useful to use without having to go into a much longer rigmarole.
Every individual has a very wide, and similar width of range of immune responses to attack. But there are differences in the composition of the individual repertoire according to the differences in the virological and bacterial ecologies of the region in which the individual lives and his particular inheritance from his parents. Thus, when a new disease hits a region, an individual might be able to respond “strongly” with an appropriate immune response (inherited from one or more of his ancestors) or he might have a “gap” and might die (though his brother or sister might have inherited the appropriate response and lived).
Thus when the Spanish Conquistadores went to Central America in the 16th century, 90% of the Mayans died from the new virus strains that the Spanish had brought with them from Europe. The indigenous immune systems had a different repertoire. The same applied to the early British employees of the East India Company going to India — they had a very high rate of mortality initially because they met diseases which British people hadn’t come across for millennia and the immunity had drifted out of their regional genetic repertoire.
What epidemiologists are deeply worried about is that as a much wider range of vaccines becomes available against a much wider variety of endemic diseases then, increasingly, on a world-wide basis there are increasing “gaps” in the overall repertoire and thus many individuals are “weak” in being able to respond to newly mutating viruses. Thus, a new virus can come along and inflict a very high mortality on people in many different regions of the world causing mass deaths until an appropriate vaccine can be developed — and this may take months or years.
This is what epidemiologists are warning the world about, just as they also warned about the peril of the growth of bacterial resistance to the range of antibiotics — and which is now becoming a very serious problem in almost every hospital in the world — in the adanced countries and the Third World. But just as the general medical profession took no notice about epidemiologists’ warnings about the profligate use of antibiotics against bacterial infections (and a great many other complaints which didn’t even respond to antibiotics) so no-one is taking much notice about the dangers of profligate use of vaccinations as, apparently, the only way to treat new virus diseases.
In the recent case of the out break of ebola in east Africa and the subsequent development of a vaccines against it, many of those who are now congratulating themselves really ought not to. Several different vaccines in different countries around the world, including Russia, China, this country, America and Canada were proposed but each of them was only effective against a limited number of the different ebola strains which had mutated in the months since the original outbreak. The Canadian one proved to have the widest efffectiveness and this was the one used to finish the epidemic — in the main. But there are still other strains out there which will inevitably cause future outbreaks.
The only sure response to a new virus like ebola is quarantining. If the World Health Organisation had not dilly-dalled in January 2014 when the first outbreak of the deadly ebola disease was first noticed then the disease could have been stamped out completely by quarantining long before even more rapacious strains of the disease had mutated. Thus, in the follwoing three or four months before the WHO and other charities woke up, ebola had become very much more widespread than it might have been.
Fortunately, there will probably never be a virus or a bacterium which will have a 100% mortality on the human genome. New mutating viruses or bacteria have to permutate between the four basic components of DNA and although the number of new possibilities are in their millions, all humans born also have new responses which follow from random mutations in their immune systems that occur at every fertilization event. Thus, among the billions of people on earth, a percentage of humans — albeit a very low one in some cases — are always likely to survive, however exotic a new virus or bacterium.
The survivability of the human genome against all attacks cannot be guaranteed because this depends on the overall variability of the human genome compared with other animals. The human genome has much less variablity than that of the chimpanzee, for example. Among the world human population, most of us are predominantly a sub-branch of the original African human population — since the exodus from Africa 60,000 years ago — and thus the genetic variability of most of us means that we are likely to be less prepared against some deadly virological and bacterial attack than Africans are.
Thus the ecology of life on earth is a grand contest between viruses and bacteria, and between them and plants and animals (and between plants and animals by eating!). Hopefully it will always be a contest without outright winners!