As late fall turns into winter, perennial concern arise from influenza. Some people are frightened about the flu for good reasons, others have unwarranted fears based on limited knowledge of fly epidemics such as the one that broke out in 1918. The reasonable fears we have stem from the particular vulnerabilities of some groups, such as the elderly, kids and pregnant women.
The unwarranted fears are based on expectation of an influenza plague as lethal as the 1918 pandemic, during which there were over thirty tines as many influenza deaths in USA as occur in a normal year. About one out of hundred people on earth died from influenza within twelve months.
Experts have been looking at the form of the two protein molecules that stick out of surface of the influenza virus. One protein is hemagglutinin, which allows the virus to bind to our cells for entry. The other is neuraminidase, which keeps the flu virus molecules from sticking to each other. If the influenza experts detect a combination of these proteins that is similar to the combination of the 1918 pandemic viruses, which is referred to as H1N1, alarm spreads same as nowadays.
H1N1 virus is not new, it happen before at 1976, causing a cascade of events that flowed out of control. When a large proportion of the population has not been exposed to a particular flu H1N1, the potential for a global outbreak of influenza is especially great. Flu experts were anxious in 1976 because they were nearing a period when immunity to the H1N1 combination would virtually have disappeared from the population.
People who were infected as babies in 1918 and survived were about sixty years old in 1976. So everyone who was less than sixty years old had no immunity to the 1918 virus. The anxiety was magnified by political forces, which pushed through a “swine flu” vaccination program, which caused a paralytic disease called Guillain Barre syndrome in about five hundred people, about twenty five of whom died. The benefits of the program are hard to gauge. Probably no more than a few lives were saved from flu outbreak that apparently burned out on its own.
Concern over a pandemic of an H1N1 virus was justified, but anxiety about a re visitation of a virus with the harmfulness of the 1918 influenza viruses was not.
We are seeing flu viruses that have the H1N1 combination but do not have exceptionally high virulence. We will fail to see a recurrence of a pandemic influenza with the kind of lethality that characterized the 1918 pandemic.