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Dr. Christopher S. Baird

What is the debate over vaccines?

Category: Health      Published: June 17, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and Associate Professor of Physics at West Texas A&M University

child with smallpox
Smallpox infected 50 million per year in the 1950's. Smallpox has been completely eradicated from the planet thanks to an intense vaccination campaign. The last case of smallpox was in 1977. Public Domain Image, source: CDC.

There is no real debate over vaccines. Essentially all medical doctors, scientists, research technicians, healthcare administrators, and politicians agree that vaccines are safe, effective, and lifesaving. This huge consensus among educated professionals was reached because of the large body of evidence demonstrating the efficacy and safety of vaccines. The small but vocal minority that argues against the use of vaccines consists of non-scientific "alternative" healthcare peddlers and their gullible victims. A legitimate debate in educated circles requires evidence on both sides of the debate. Seeing as there is no evidence that vaccines fail or do significant harm, there is no real debate. Let us see what a legitimate scientific debate looks like and how it is resolved, and then look at some numbers.

By the end of the 19th century, James Clerk Maxwell had successfully united all of the equations describing electricity, magnetism, and electromagnetic phenomena into one complete set of laws now known as Maxwell's equations. Maxwell's equations matched numerous experimental results and successfully united previously distinct fields such as electronics, radio waves, optics, and magnetism. Interestingly, Maxwell's equations describe light as electromagnetic waves. However, in the years between 1900 and 1910, the situation started to unravel for the wave theory of light. Max Plank demonstrated that experimental measurements of blackbody radiation (the light from glowing, hot objects) could only be accurately described by equations if light was taken to be composed of fundamental particles, and not waves. Furthermore, Einstein demonstrated in 1905 that the nature of the photoelectric effect (when light knocks electrons out of materials) could only be described if light consists of particles. A genuine debate ensued in the scientific community over the nature of light: whether it is composed of waves or of particles. There was solid experimental evidence on both sides of the debate. Some experiments showed that light is a wave and others showed that light is a particle. Both sides had sound theoretical treatments describing their respective experiments.

How does a genuine scientific debate like this get resolved? The only way forward is to develop a new theory that successfully describes all experiments. In the first few decades of the 20th century, Plank, Bohr, Heisenberg, Einstein, Schrodinger, Dirac, Pauli and many others did just that by developing quantum theory. Quantum theory has been mainstream science for almost a century and is at the heart of every laser and computer chip. Interestingly, quantum theory describes light as both a particle and a wave. More accurately, it describes light as something complex (a quantized probability wavefunction) that acts somewhat like a wave in certain ways and somewhat like a particle in other ways. Modern experiments routinely show that light can act like a wave and like a particle, at the same time.

The point is that genuine debates do exist in science, but they require substantial evidence on both sides, and they end up being resolved through more experiments and better theories. There is no way to resolve the vaccines "debate" because there is no evidence that vaccines are ineffective and harmful to begin with. There is therefore no genuine debate surrounding vaccines. A better description of the status of vaccines would be: A scientific consensus exists that vaccines are safe and effective, which is based on a large body of evidence, while a small vaccine-denialism subculture exists that has a hard time thinking scientifically. For vaccine denialists, an infinite amount of experimental evidence will never change their mind because they are not thinking scientifically to begin with. The existence of a science-denying subculture in educated countries is not unique to vaccines. There exists small pockets of people who believe cell phones cause cancer, the position of distant stars controls their destiny, and magnets have healing properties. But considering the life-saving property of vaccines, vaccine denialism is the most dangerous type of science denialism.

Let us look at some numbers. The rate of U.S. rubella infection in the year that a vaccine was released (1969) was 27 people per 100,000 as reported by the CDC. Within 10 years of distributing and administering the rubella vaccine, the rate had dropped to 2 people per 100,000. The current incidence of rubella in the U.S. is less that 0.1 people per 100,000. The CDC further reports that Polio was contracted at a rate of 10 people per 100,000 in 1955 in the U.S., the year Polio vaccinations began to be distributed. By 1975, the Polio infection rate had dropped to just 0.01 people per 100,000. The measles infection rate went from 400 thousand total cases in the year the vaccine came out (1963) to 20 thousand total cases five years later, and is now at less than 1 thousand cases per year. The mumps infection rate was at 90 people per 100,000 per year when the mumps vaccine was introduced and fell to 1 per 100,000 in 1984. The tetanus infection rate was at 2.9 cases per million people in 1955 and after several decades of vaccinations dropped to less than 0.3 cases per million. Because vaccines have been deployed in every country on the globe, vaccines are one of the largest scientific experiments ever run. After centuries of use by billions of people, the effectiveness of vaccines is one of the most verified science facts of all time. Considering that the effectiveness of vaccines is one of the most experimentally-verified science facts of all time, and that denying the effectiveness of vaccines is so life threatening, vaccine denialism is one of the most irrational beliefs a person can have.

In the 1950's, the smallpox virus was infecting humans globally at a rate of 50 million per year. After an intense global vaccination campaign lead by the World Health Organization that spanned two decades, smallpox was completely eradicated from the planet. The last case of smallpox was contracted in 1977 and there have been no cases since then, thanks to vaccines. Vaccine denialists claim that these drops in infectious disease rates are caused by better hygiene and access to vitamins. But this statement does not match the scientific data. The rates for infectious diseases that have no vaccine, such as Salmonella, are not dropping and in many cases have increased during the last 50 years, despite better hygiene and nutrition. The CDC retorts, "Are we expected to believe that better sanitation caused incidence of each disease to drop, just at the time a vaccine for that disease was introduced?" Such thinking is simply irrational.

Arguing against vaccines is not only unwise and unscientific, it is frankly unethical and deadly. An anti-vaccination campaign conducted in Stockholm in 1873 reduced the portion of the population that was vaccinated against smallpox from 90% to 40%. A smallpox epidemic ensued in Stockholm that did not abate until vaccinations became mandatory. Similar anti-vaccination-induced outbreaks happened in the United Kingdom in the 1970's with pertussis, in Sweden in the 1980's with pertussis, in North Dublin in 2000 with measles, in Nigeria in the 2000's with Polio, and in Indiana in 2005 with measles.

Polio ward
Before the polio vaccine was developed, whole communities of children spent summer vacation in iron lungs instead of at camp. Public Domain Image, source: NIH.

Some vaccine denialists argue that taking too many vaccines will overload, and therefore weaken, a child's immune system. But scientific evidence does not support this claim. Vaccines are used in a dead or inactivated form so that they don't actually infect the patient the way the original pathogen does. A child receiving a vaccine may feel mildly sick for a few days, but these symptoms are not because the vaccine is damaging his tissue. These symptoms are the natural effects of an immune system being activated (people with allergies know all too well what an activated immune system feels like). With vaccines, there is nothing for the immune system to actually fight. The body does not have to repair tissue after vaccination as no tissue is damaged (aside from the poke of the needle). The body's immune system creates antibodies in response to the vaccine that help it identify the real pathogen when it comes along. Some vaccine denialists mistrust vaccines because they don't seem natural. In fact, vaccines don't replace the body's immune system or directly fight viruses. Vaccines just activate the body's natural defense system by showing it what pathogens look like.

Young people in modernized countries today who don't read history books simply have no idea how different life was before vaccines came along. Before the polio vaccine was developed, whole communities of children spent their summer vacation in iron lungs, not at camp. One in four babies did not survive to their first birthday in the 1850's in the U.S. That number dropped to about 1 in 17 in 1935, and then to about 1 in 150 babies in 2007, thanks largely to vaccines. Thanks to vaccines, many young people in developed countries today have never experienced a serious infectious disease or seen anyone else experience a serious infectious disease. As a result, they may assume that serious infectious diseases are no worse than a head cold. They simply have no conception of the death and suffering that vaccines protect against. In the textbook Vaccines, Dr. Stanley Plotkinmore reports that more lives have been saved by vaccines than by any other medical approach, including antibiotics.

Topics: scientific debate, vaccination, vaccine denialism, vaccines, vaccines debate