How does vaccination work?
By the late 18th century vaccination had come a long way, but how did it work?
Over millions of years, the human body has evolved numerous ways of protecting itself against attacks of various sorts. One shield in its arsenal is antibodies. When a virus makes the body sick antibodies are produced that learn to identify and fight the disease. When exposed to attack by that same virus again antibodies destroy it, the body is now immune.
This is why someone who survives smallpox is usually immune to the disease. Measles also produces the same response – a child who gets measles become immune to later attack.
A similar response occurs in Dengue but there is a complication: Dengue comes in four serotypes, or variations, DEN-1, DEN-2, DEN-3, and DEN-4. Catching one type of Dengue makes one immune only to that type of Dengue but not the other three types. This has been the challenge for those trying to produce a vaccine for Dengue – a vaccine that only protects from one kind of Dengue leaves the patient vulnerable to the other three.
In the case of early smallpox vaccination techniques known as variolation or inoculation, the patient suffered a mild, survivable form of the disease that developed antibodies against smallpox.
What if the body could be fooled into believing it had been attacked by a disease so that it developed antibodies against the real thing? That brings us to the work of Edward Jenner.
Jenner was a British physician who had undergone variolation as a child. Later he met a milkmaid who boasted that she would never be ugly with the effects of Smallpox because she had already caught a disease called cowpox that left her immune to the more serious disease. In fact, the phenomenon was already known to country doctors – milkmaids did not get the Smallpox that was ravaging the rest of the country.
After experiments, Jenner concluded that cowpox did, indeed, produce immunity to Smallpox. He was the first to vigorously promote vaccination this way. It was controversial, but he was right.
Our next stop is Boston, Massachusetts in 1721.
The Boston Controversy
In 1721 Boston, Massachusetts, was a British Colony. One if its leading lights was a Puritan minister and community leader called Cotton Mather.
That year, one of the biggest outbreaks of Smallpox in the colonies that century occurred. Out of a population of 11,000, over 6000 cases were reported with 850 dying from the disease. At the urging of Cotton Mather, a physician called Zabdiel Boylston to begin inoculting people against Smallpox. Some of those inoculated died and a bomb was thrown through Cotton Mather’s window with the message: ““Cotton Mather, you dog, dam you! I’ll inoculate you with this; with a pox to you.’’
Such a statement is familiar to anyone who has criticised the Philippine PAO claims regarding Dengvaxia deaths.
What people were looking at was the number of inoculated people who died and came to the conclusion that the inoculation killed. What they did not do was compare the deaths of those who had been inoculated to those who had not been treated. Data showed that 2 percent of those inoculated died but near;y 15 percent of those who had not been inoculated died.
The eventual outcome was the virtual elimination of smallpox in New England over a matter of a few years.
It was a case of confirmation bias: If one only looks at those who have been vaccinated and subsequently died, one comes to the conclusion that vaccination kills. All persons autopsied by the Philippine Public Attorney’s Office had been vaccinated against Dengue, we will explore why that should be in a later piece. As yet there is no study of how many died of Dengue who had not been vaccinated yet that is critical public health data on which decisions should be made.
Vaccination itself has always had its critics. I well remember a school friend who spoke out against vaccination in the 1960s in the UK, des[ite its proven success at eliminating childhood disease like polio, diphtheria and whooping cough. But there was no social media in those days. It took a fraudulent paper by a crooked scientist – yes, some are – who was paid $600,000 dollars by a group of lawyers to fake a paper claiming a link between Rubella vaccine and Autism, to get an anti-vaccination movement off the ground.
The Dengvaxia issue has been adopted by the anti-vaxxer movement and is causing the increase of vaccine-preventable diseases in the Philippines, using the PAO claims as a springboard.
Not let’s look at one of the most remarkable event in the history of vaccination in the Philippines: The Balmis Expedition, the first major assault on Smallpox in the Philippines.