Some dates worth remembering:
1862: Louis Pasteur discovers the eponymous process of pasteurization (based on work done by Lazzaro Spallanzani 100 years earlier), first used in beer and wine, but most importantly in milk. As the process is gradually introduced (the first US state required it in 1947, the federal government for interstate commerce in 1973). It took a while, but with its introduction the frequency of serious and often life-threatening infections coming from unpasteurized (= “raw”) milk, including streptococcus, typhoid, typhus, and TB, among others, dramatically decreased. Health was improved.
2024: The US President-elect, Donald Trump, announces that he will nominate Robert F. Kennedy, Jr., who advocates the drinking of unpasteurized milk, to the cabinet post of Secretary of Health and Human Services.
1952: During the last major polio epidemic in the US, a friend comes to visit our family on a Saturday to see my new baby sister. On Monday, she comes down with polio and spends the rest of her life in a wheelchair. My parents are worried about their children having been infected, more about the greater risk to 3-year-old me than the baby, as polio in infants was uncommon. I do not get clinical polio (see * below) and soon thereafter receive both the Salk (injection) and later the Sabin (oral) polio vaccines. During this decade I also come down with clinical cases of measles, mumps, German measles (rubella), and chicken pox. The last was quite unpleasant, but I didn’t die and had no significant after-effects. The vaccine against measles (and mumps and rubella) were released in 1963. The rates of these diseases, especially measles which caused the most deaths, plummet. Most measles outbreaks since have been in populations in which people did not immunize their children, notably in 2019 among Hasidic Jews in Brooklyn.
As a young doctor at a public hospital in the 1970s, one of the common and feared infections we saw in the pediatric emergency room was that caused by the bacteria Hemophilus influenza b (not the same as the virus influenza). It commonly caused ear infections, but also very serious meningitis, and, most scary to us, epiglottitis, in which the epiglottis, the piece of tissue in your throat that prevents you from breathing in food, swells very large very fast and can completely cut off a child’s breathing unless a breathing tube can be placed in time (and it is difficult with the swelling). In 1985, the vaccine against H flu b was introduced, and these infections and deaths almost disappeared. Varicella (chicken pox) vaccine was not released until 1995, and the rate of those infected (and then later infected with shingles, a resurgence of the same virus, known as Varicella-Zoster) plummeted. Before the vaccine was released, about 4 million cases of chicken pox, with over 10,000 hospitalizations and 100 deaths, occurred (mostly among children) annually in the US.
2024: The US President-elect, Donald Trump, announces that he will nominate Robert F. Kennedy, Jr., who believes all vaccines are bad and should be avoided, to the cabinet post of Secretary of Health and Human Services.
The difference between individual and public health is important, and bears repeating. For the individual, getting a disease (infectious or not) is 0% or 100%. If something happens to “one in a million” people it is very rare (including serious reactions to vaccines, which do not, incidentally, include autism) but if you are the one, it is 100% for you. On the other hand, if something affects 99% of people, but you are in the 1%, you are lucky. Public health looks at trying to prevent (or contain, if they are infectious) diseases by looking at the impact of disease, or preventive measure (e.g., vaccines, pasteurization) on the population**. Pointing to individual exceptions (“my grandfather drank a quart of whisky and smoked two packs of cigarettes a day and lived to be 100”, or “we drank raw milk all the time and we’re healthy”) does not change that unless an subgroup that is not susceptible can be identified (e.g., biological males do not get cervical cancer – although they still should be immunized against HPV as they can transmit it). Some things may decrease the risk; those drinking raw milk direct from the cow on their farm are at lower risk of infections than those who consume it after it has been shipped and had days, or longer, to become infected. Folks who are skeptical of modern medicine often emphasize “prevention”, but this is not a magic incantation. Vaccines are one of the few things we have that actually prevent serious disease. Also avoiding foods that have a significant likelihood of being infected – tainted meat, shellfish, water infected with sewage (water remains the largest cause of death, through infant diarrhea; the main reason commercial campaigns to replace safe breastfeeding with formula that needs to be rehydrated are terrible), or raw milk.
Human progress is not unidirectional. There are often steps backwards, motivated by misinformation, financial gain, fantasies, (some people’s interpretation of) religious beliefs, political gain, and others. The appointment and confirmation of Kennedy would be a big step backward. The implementation of the policies he advocates will take us back more than a century.
There is a – very important – place for evidence and truth.
*Even though poliovirus infects almost everyone exposed who is susceptible, not everyone who is infected with poliovirus gets clinical polio; it is about 10%. Measles, on the other hand, also infects almost 100% of susceptible people, and virtually everyone infected gets clinical disease.
**It is worth noting that even the practice of one-on-one clinical medicine is based on applied epidemiology, the science of studying disease in populations. Why we may suspect a certain condition in a person with certain symptoms is because, in a population of people who are similar and who have these symptoms, these are the common causes. Same for treatments: we don’t say “well, the last person I saw with diabetes responded well to insulin, but you’re a different person, so let’s try digitalis.”
