When retired allergist and immunologist Dr. Donald Stevenson spoke to the Torrey Pines Rotary Club during its Feb. 3, 2016 meeting at Rock Bottom Brewery, he offered an important disclaimer: “I’m not hired by any vaccine company … I have no relationship with them.” This was good to know because the bulk of his lecture, “Influenza: The Killer Virus. Facts/Fiction about Vaccinations,” covered the structure, history, benefits of and debunking myths about the flu vaccine.
“Newspapers talk a lot about Ebola, Zika and other viruses, but this one is literally the worst killer the world has ever known,” Stevenson said of the nasty, but common, respiratory infection. He called the number of folks not getting the flu vaccine “a tragedy.”
Stevenson, who retired from the Scripps Clinic Medical Group and The Scripps Research Institute in January, explained that there are three types of influenza: A, B and C. Type A can be passed through animals (primarily pigs), birds and humans; while Types B and C can only be carried and passed by humans.
Breaking down the science of how a flu virus works, he said the human immune system recognizes structures on the outside of the virus cell, which he compared to a colorful coat. “Some coats are green, some are red, some are blue, some are yellow, which our system learns to recognize,” he said. “But each year, a new virus comes out that has a different-colored coat than what our immune system has already seen and is ready to combat. And some flu viruses go through a minor mutation our system can partially recognize – such as a chartreuse coat instead of green one – that’s why some viruses are easier to attack than others.”
In the early 1900s, he said, science started to better understand how a virus works, and medical professionals were better able to fight influenza at the molecular level. One of the first recorded flu epidemics was during World War I. In 1938, readying for World War II, the “killed” influenza virus vaccine was introduced, and used exclusively by the military, Stevenson said. As a result, there were no epidemics of U.S. troops during World War II.
Epidemics since then have been sporadic, he added, and took place in 1957, 1968, 2004 and 2009.
In 1976, there was what has been referred to as the “swine flu debacle,” Stevenson said, which may have been a precursor to the modern conception that the flu vaccine has severe side effects or causes other diseases. “One soldier died at Fort Dix of a flu that appeared to be close to a 1918 strain … The Centers for Disease Control and Prevention (CDC) was so concerned it was the same strain as in 1918, that it recommended the entire U.S. population be immunized,” he said.
In the rush of things, about 40 million people (24 percent of the population at that time) were immunized. At the same time, there was a slight influx of Guillain-Barre Syndrome cases reported. (G-B causes paralysis, and in some cases, paralysis of the chest, leading to death.) It was suggested in the press that the flu vaccine causes Guillain-Barre. “The government got really nervous and suspended vaccinations. This was a terrible thing to do because … the federal government was basically saying Guillain-Barre was caused by the flu vaccine, and that was tragic because the actual reason for the increase in Guillain-Barre was increased reporting.”
Fear that the flu vaccine caused other ailments is one of the main reasons Dr. Stevenson said his patients would choose not to get vaccinated, although he assured them the vaccine is made using a “killed” or “dead” virus.
“A vaccine is constructed based on three or four predominant strains selected by the World Health Organization in July of each year. These seed viruses are placed in chick embryos for about three months (the time is takes for the virus to “grow”) and then scientists carry out a process called Zone Electrophoresis to reduce the egg protein to less than one microgram per milliliter (so the vaccine can be given to those with egg allergies without stimulating a reaction),” he explained. “Scientists then harvest the virus and kill it. The dead virus initiates a less robust immune response, and there is some memory recall from the immune system having seen that ‘coat’ before.
“Conspiracy theorists who make a career out of denigrating vaccines without medical knowledge, create a headwind for doctors trying to promote vaccines.” Further, conflicting information from the CDC has also cast some doubt, he said.
The CDC issued a statement that children who get a severe reaction from egg allergies can get the vaccine, but only in their allergist’s office. “But, these are diametrical thoughts; one is saying there’s not enough egg protein in a flu vaccine to produce an allergic reaction, but yet you still have to get the vaccine in the allergist’s office,” he said.
Advocating for more people to get the vaccine, Dr. Stevenson said approximately 100,000 to 200,000 people die each year from influenza. And because Type A influenza can be carried by people or birds, it can travel worldwide. But if every human being on Earth got the flu vaccine, types B and C would be eradicated because there would be no host.
Following the lecture, Rotarians had the chance to ask Dr. Stevenson questions.
For more information about influenza — including facts, symptoms, vaccination information and more — visit cdc.gov/flu