Let me break down the overall scheme of vaccination, real quick.
- You get exposed to a dead/weakened/chunks of a pathogen (virus, bacterial toxin like tetanus, etc).
- Your body reacts to the vaccine ‘invader’ and triggers an adaptive immune response.
- Your adaptive immune system ‘remembers’ what it has seen, so when you are exposed to the real virus/bacteria/etc, it is already ready, and kills the pathogen before it can make you sick.
That is the ideal situation.
Sometimes your body just ignores the vaccine. The vaccine is dead, so it degrades before your body even sees it, much less develops the appropriate adaptive immune response.
Sometimes your adaptive immune system ‘forgets’. You get a vaccine, six months later you still have a great adaptive immune response to the pathogen. Six years later your immune system is like ‘lol wut? Daves not here, man!’
And even under ‘ideal’ circumstances, the adaptive immune response you make to a pathogen isnt perfect. It might make it so that if you are expose to the pathogen, you get a milder disease, because your immune system got a head start… but you still get sick.
And then there are the folks who just *cant* get vaccines for genuine medical reasons, like genetic or pharmaceutically induced immune suppression. ‘Weak’ virus in a vaccine for you? Meh. ‘Weak’ virus in a vaccine for someone who just got a new lung? Eeeeeeeeeeeeeh.
But we can still have our bases covered with vaccines as long as everyone, who medically can be vaccinated, is vaccinated. Most of us are properly protected, and we protect the folks who cant get vaccines and the random folks who didnt respond well to the vaccine and everyone is protected.
Alas, there are bad parents and assholes among us who do not vaccinate their children, who grow up to be unvaccinated teenagers, unvaccinated adults, etc, and they travel all around the world to places where people do not have the luxury of turning down vaccines, where preventable diseases are endemic, and these assholes bring them home to the US.
So, of course the people who cannot be vaccinated are at risk.
And, the random people who didnt respond well are at risk (could be me! could be you!).
But most of us would be safe in an ‘outbreak’ scenareo, right?
Apparently, sometimes, no.
A long time ago, in a galaxy far far away, parents actually loved their children, and made sure they got the MMR vaccine to protect them from measles, mumps and rubella. These diseases became so rare physicians didnt even know what they looked like, at least in the US. These diseases were fairy tale villains, conquered long ago.
And then some chode made up some data saying MMR was dangerous, and for whatever personal psychological reasons, parents refused to protect their children with vaccines, including MMR. Vaccination rates go down, herd immunity breaks down, people start getting sick from preventable diseases. Dead villains rising from the grave.
So in 2009-2010, there was an outbreak of mumps in New Jersey/New York, predominantly in Orthodox Jewish communities. Over 3500 people got mumps.
“AH-HA!” Some of you might be saying. “I bet they refused vaccination for ‘religious’ reasons, and thats why they all got sick! STUPID!”
The Orthodox Jewish communities impacted by this outbreak were not opposed to vaccines. They had totally normal vaccination rates.
… But… If everyone was vaccinated… how did do many people get sick? What happened to herd immunity?
Genetics? Bad batch of vaccines?
The index case patient in this outbreak was a twice-vaccinated 11-year-old boy who returned to the United States on June 17, 2009, from the United Kingdom, a country that was experiencing a large mumps outbreak at that time.
Patient Zero should have been protected, but he wasnt.
The majority of cases — 71% (2479 of the 3502 cases) — occurred among males.
…10% were unvaccinated, 14% had received one dose of MMR vaccine, and 76% had received two doses of MMR vaccine…
One dose should have been fine (ish), two is better, but 90% of the people who got mumps were vaccinated. And 71% were males, not including Patient Zero (also male and properly vaccinated).
What the hell is going on here?
The features of this outbreak are best explained by intense exposures, particularly among boys in schools, that overwhelmed the protection afforded by the vaccine. In general, Orthodox girls receive conventional schooling, whereas boys in yeshivas receive intense religious education starting at 12 years of age, with school days that are up to 15 hours long. Yeshiva study is typically interactive, involving a “chavrusa” (a study partner). Partners face each other across narrow tables or lecterns to study religious texts; the format is face-to-face, often with animated discussion. Frequently, several pairs of students study at a single table. A typical day involves several study sessions, with students changing partners for each session.
The protection we get from vaccines is not perfect, but it is enough to protect us from a random exposure to some jerk at the Superbowl or something.
But if you are exposed to a ‘high dose’ of pathogen, from lots of transmission friendly interactions, its too much for even an educated immune system, and you will get sick.
People got really sick from this outbreak. Not ‘just mumps’, but pelvic inflammation, brain inflammation, pancreatitis– One person went deaf. Permanently. PERMANENTLY.
Those Mommy Warriors who dont protect their kids?
You could be their next victim. Even if you are vaccinated.