Why did the flu of 19 18 kill so many otherwise healthy young people?

Seasonal influenza vaccination from 20 17 to 20 18 is in progress. Next year will be the 0/00th anniversary of the outbreak of influenza/KLOC-,and about 40 million people will die of influenza. It is time to consider the possibility of infectious diseases, which will spread all over the world and affect many people, and the importance of taking measures to curb infectious diseases.

This infectious disease of 19 18 is unusual. It killed many healthy people between the ages of 20 and 40, including millions of soldiers in the First World War ... In contrast, people who died of flu were usually under the age of 5 or over 75.

The pathogenic factors of 19 18 influenza are still unknown. Modern scientists sequenced the DNA of 19 18 virus from the lung samples preserved by the victims. However, this does not solve the mystery of why so many healthy young people were killed.

I began to investigate the disappearance of a young immigrant to the United States in World War I, and uncovering his story also gave me a new understanding of the hypothesis that 19 18 young people's immune system could not protect them from harm.

19 18 Influenza and World War I

The certificate portrays the Colombian goddess as the embodiment of the United States and is awarded to men and women who served in the First World War. Decades later, such a proof surfaced. This certificate is in memory of Adolf Saltini, discovered by his nephews Thomas, Richard and Robert Saltini, who never knew him.

A certificate is a piece of information in the past. It's calling to me, because I just got the certificate of certified genealogist, and I spent most of my time as a scientist tracking a gene that regulates immune cells. What happened to Adolf? ""An Italian immigrated to the United States, and Adolf Saltini died of the flu in the army. (Provided by Robert Saltini)

A little investigation confirmed Adolf's shipping list, showing that he was born in Italy in 1889 and immigrated to Boston in 19 13. His draft card shows that he works in a country club in Newton, a suburb of Boston. In order to learn more, Robert Satini bought a book named 1930 "Newton War Memorial" in Yi Bei. This book provides some clues:1965438+In March 2008, Adolf was drafted into the army and was ordered to report to Camp Devens, 35 miles from Boston. Later, he was transferred to an engineering training regiment.

Later, I posted questions on the "American Military Forum". Here, military history enthusiasts explain that the Army Corps of Engineers once trained soldiers at Camp A.A. Humphries in Virginia. Maybe adolf went to this camp? 1918 In the spring of 2008, when a slight flu spread, this deadly virus appeared in the United States on Tuesday, August 27th, when three naval dockers at Commonwealth Pier in Boston fell ill. Within 48 hours, dozens more men were infected. 10 days later, the flu killed the camp in Devens. William Welch, a famous pathologist from Johns Hopkins University, was invited to attend. He realized that "this must be some new infectious disease or plague." Virus is a tiny medium that can pass through a fine filter, and people know little about it.

With the mobilization of World War I, influenza spread to military facilities and ordinary people all over the United States. It attacked Humphrey camp in mid-September and killed more than 400 people in the following month. Among them is Adolf Saltini, 29 and a half years old. Adolf's body was transported back to Boston.

There is a sculpture at the lower part of the inverted column on his grave, which is the epitome of his early death.

It's 19 18 flu.

The remains of the victims and the knowledge of 19 18 influenza have promoted many scientific advances, including the discovery of influenza virus. However, the virus itself did not cause most deaths. On the contrary, a few people infected by virus are prone to pneumonia due to the secondary infection of bacteria. Before antibiotics appeared, pneumonia could be fatal.

Recent analysis shows that 19 18 has the highest death toll among people born around 1889, just like Adolf. There was an early outbreak of influenza at that time, and the virus involved may be different from the strain of 19 18. These analyses have produced a new hypothesis on the susceptibility of healthy young people in 19 18, as follows.

Adolf Saltini's tombstone at St. Michael's Cemetery (provided by Michael Sheehan, manager of St. Michael's Cemetery) shows that exposure to influenza virus at a young age will increase the resistance to subsequent infection with the same or similar virus. On the other hand, people who are children during the epidemic may not be resistant to other different viruses. Influenza viruses are divided into several groups related to evolution. The virus transmitted by Adolf as a baby may be in the so-called "group 2", while the virus of 19 18 is in the "group 1". So Adolf can't have a good ability to deal with this "1 group" virus. In fact, exposure to "Group 2" virus at the age of 19 18 may lead to abnormal reaction to "1 group" virus and aggravate his condition. "KDSP" and "KDSP" supported this hypothesis when the influenza virus appeared in 1968. Is in the "second group", in 19 18 against "1 group" influenza.

It will have a serious impact on children from 20 18 and beyond. What causes a common recurrent disease to evolve into an epidemic that is extremely fatal to healthy people? Will it happen again? A similar situation may happen again until 19 18 is better understood. Experts worry that a new epidemic of influenza or another source of infection may lead to millions of deaths. Bill Gates is leading the investment to prevent this from happening.

Influenza vaccine is produced every year by monitoring the strains spread in the first few months of the influenza season. A vaccine can be produced with a time lag of several months. Unfortunately, due to the rapid mutation of influenza virus, this lag will also lead to the emergence of virus mutations, and these mutations have poor targeting for vaccines. In addition, influenza pandemics often occur in viral gene recombination. This includes combining genetic material from different viruses, which may happen suddenly and unpredictably.

An influenza virus is currently killing chickens in Asia and recently killed people who have contact with chickens. This virus belongs to a subtype, and it is not known that it will cause an epidemic. It has not proved its ability to spread from person to person. However, whether this ability will appear in the continuous process of virus evolution. Chicken viruses "KDSP" and "KDSP" are both in the "second group", so if it becomes popular, children around the "second group" of 1968 may get some protection. I was born much earlier, and the "first group" viruses began to spread when I was a child. If the next epidemic virus belongs to the "second group", I may have no resistance.

This is an early stage of understanding how previous contact affects influenza susceptibility, especially for people born in the past 30 or 40 years. Since 1977, the viruses of "group I" and "group II" have been spreading. People born after that may develop resistance to one virus or another, which is based on the virus they first came into contact with. This is good news for the near future, because if there is an outbreak of "1" or "2" virus, some people should be protected. At the same time, if you are under 40 years old and find another epidemic, you need more information to guess whether you are susceptible or resistant.

This article was originally published in a conversation with Dr. Ruth Craig, Professor of Pharmacology and Toxicology at Dartmouth College.