Lately there has been an outbreak of measles, a vaccine preventable disease, along with an outbreak of people yelling at each other. There have been angry exchanges between people who would like all children vaccinated according to the recommended guidelines and people who support the rights of parents to choose which vaccines to give their children, if any, and when to give them. There has been much focus on the assertion, particularly, that the Measles/Mumps/Rubella vaccination (MMR) might cause autism. There is no believable evidence to support that assertion, but the questions of whether vaccination is safe and whether it should be required are much more interesting.
Yay Vaccines!
I am a big fan of vaccination as a means of fighting disease. It is an ingenious concept. The recipient of a vaccination gets an injection or oral dose of a weakened virus or bacterium or an inactive part of one, which causes the body's own immune system to produce cells that will recognize and kill the real virus or bacterium if it enters the body at some future date. Vaccinations are so much more elegant than antibiotics, which are chemicals that are broadly active against a whole bunch of different agents and only last until the body inactivates or excretes them. Vaccines stimulate the body's own very complex and amazingly effective systems for fighting infection in much the same way that natural infections or exposures would. These systems are then available to prevent disease whenever the need arises.
Herd immunity--that's how vaccines eradicate diseases
Vaccines are ingenious at the individual level, but they are even more ingenious on the level of populations. A vaccine raises an individual's resistance to a disease, but each individual is still somewhat vulnerable to that disease because the body's defenses are not absolute. Some vaccines are more effective than others, and some people have a more robust response than others. Infectious diseases persist in our communities because they move from one person to another. If the vast majority of people in the community are immune to a disease, as can be achieved with vaccination, the disease cannot be transmitted and will die out. The few people in the population who are not immune are protected by the many who are since the likelihood of coming into contact with someone with an active infection in such a community is very low. This effect is known as "herd immunity" and is one of the primary reasons that we should care about whether other people get vaccinated.
Curing smallpox
The word "vaccination" comes from the word root for cow, since the first vaccine in common use was derived from cows to fight smallpox. It had been observed that dairy maids who were infected with cowpox, a pustular disease, from touching the udders of infected cows did not get smallpox. In 1796 the physician Edward Jenner created a vaccine from that virus which became widely used. In 1979 smallpox, which killed as many as 500 million people in the 20th century alone, was declared eradicated. The vaccine was mandatory for school children, and I'm pretty sure I got it when I was a kid. It usually left a little scar on the upper arm but otherwise only rarely had side effects. Once in awhile, when a child had something that predisposed him or her to more serious infections, the vaccination would cause an overall body pustular rash which was very nasty. The vaccine is no longer in common use, but still exists, especially for preventing the tropical disease monkeypox which is similar to smallpox but milder.
Goodbye, polio
Other vaccine successes include polio, which was a virus that primarily infected children via the fecal-oral route, and caused paralysis, which was often fatal or disabling for life. The first vaccine was produced by Dr. Jonas Salk and was an injectable dead virus, and the second, close on its heels, was an oral vaccine that was a live attenuated virus (meaning it resembled the active virus but didn't cause polio.) Polio has been wiped out in most developed countries now due to vaccination, though it still breaks out in countries where vaccination is less common.
Measles, mumps and rubella
The measles vaccine was first licensed in 1962 and improved in 1968. It was combined with vaccines against mumps and rubella to create the MMR in 1971. It is estimated that the vaccine, in its first 20 years, prevented 52 million cases of measles, 17,400 cases of mental retardation due to measles effects on the brain and 5200 deaths. Measles causes fever, runny eyes and nose, a cough, a typical spotty rash and sometimes sore throat and spots in the mouth. I saw a case in Africa in a very miserable infant who probably had measles related pneumonia and had a reasonable chance of dying of the disease. Globally, measles vaccination has had a staggering impact. In the year 2000 it is estimated that over 700,000 people died of measles, primarily children, making it the 5th leading cause of death in kids. With a UNICEF backed measles immunization strategy, measles infections and deaths were reduced by 74% by the year 2010. Africa and India are major measles hot spots. There is no specific treatment for measles, so the only thing physicians can do is support the patient with fluids or oxygen if necessary and try to make sure the disease doesn't spread to others who might be vulnerable. Measles is very contagious. The vaccine, however, is very effective in preventing the disease. Rubella is another spots and fever disease, and can cause serious birth defects if a pregnant mother is infected with it. I had that one when I was a wee child and it didn't seem too bad, but I hope I didn't infect any pregnant people. There was no commonly available vaccine at that time. Mumps is a virus that causes swelling of the lymph nodes and can infect a young man's testicles, sometimes resulting in infertility. The vaccine is quite effective in preventing it, but not nearly as good for mumps as it is for measles.
Autism connection? Nope.
MMR is the vaccine at the center of the present controversy. In 1998 Andrew Wakefield, a gastroenterologist in England, reported 8 cases of children who developed autistic symptoms and gastrointestinal symptoms within 1 month of receiving the MMR vaccine. He proposed that the vaccine was causative, despite the fact that there was no obvious reason why it should be and there was no increase in cases of autism in the period after the MMR vaccine was introduced in England. His data was later questioned and thought to be fraudulent and the paper was retracted. Many studies have been done since then and have not shown any believable evidence that MMR causes autism, yet there are many people who still believe the vaccine/autism connection. Autism does present in early life and vaccines are given in early life, so a reasonable parent with a child who develops autism might suspect that the vaccine caused the autism, even though it did not.
But wait...not necessarily all good
Although it seems pretty clear that MMR doesn't cause autism, vaccines are not all benign and there are many diverse vaccines in common use. In the first 18 months of life the Centers for Disease Control recommends that a child receive about 24 immunizations, if I am reading this chart correctly. If successful, the vaccinations might prevent pneumonia, hepatitis, meningitis, chickenpox and the shingles that can follow in later years, tetanus, which can be fatal, whooping cough, most ear infections and rotavirus gastroenteritis. Also, of course, measles, mumps and rubella. But this is a lot of shots. Each one might cause muscle aches, listlessness and injection site redness and swelling. Children also often cry really hard and want never to go back to the doctor's office. The shot that prevents whooping cough can occasionally cause high fever and seizures and sometimes, though rarely, results in a temporary floppy unresponsive state that can't be a good thing. The reformulated version of this, which has been available for decades now, is less likely to cause these side effects, but the reactions still occur. The rubella part of the MMR can cause chronic arthritis in adults who are rubella immune if they receive MMR to boost their measles immunity.
Other vaccine greats
There are also immunizations for older children and adults which are just as miraculous and just as much of a concern with regard to side effects. These are recommended for various subgroups and situations, but not required for school aged children. This is a list of all of the vaccines available in the US. One of my favorites on this list is the chickenpox vaccination. I must have been an odd and solitary child because I never got chickenpox. My twin got it when she was in her 20s and was really sick. She still has scars from it. Chickenpox is usually an annoying skin rash, with lots of small blisters that scab after a few days, but those little blisters can occur in the mouth and esophagus which makes eating and swallowing very difficult, and the virus can cause severe pneumonia. When I was in my thirties they released the chickenpox vaccine and I got one. Since that time I have been exposed to chickenpox, which is incredibly contagious, many times without getting the disease. This means that I, and the generation of children that have gotten that vaccine will never get shingles, which is a reactivation of chickenpox which causes pain and skin lesions, sometimes with lifelong pain and scarring. Despite the fact that the flu shot is sometimes disappointingly ineffective, I happily submit to it yearly because the flu is such a nasty disease and vaccination lowers my risk of getting it or makes it less severe if I do. The human papillomavirus (HPV) vaccination is also a winner. It is indicated in girls and boys to prevent genital warts that can cause cervical and penile cancer. It is still expensive and hasn't been embraced universally yet, partly because genital warts can also be prevented by having only one sexual partner for life and making sure that he or she has never had sexual contact with anyone else. Some parents forego the vaccine for their children because they believe that this will be achievable. Cervical cancer kills 4000 women yearly and results in fertility threatening surgery and treatments in many more. The HPV vaccine could prevent these outcomes and potentially also make the dreaded pap smear obsolete.
Yellow fever: not without its problems
The yellow fever vaccine is both wonderful and terrible. In the 1600's yellow fever came from Africa to the Americas and eventually to Europe with captured African slaves. Yellow fever is so named because it causes liver failure with jaundice. It also causes nausea, vomiting, kidney failure and diffuse bleeding. It killed more soldiers in the Spanish American war than battle injuries. It slowed work on the Panama canal and infected people in Boston and other US port cities. In the early 1900's it was found to be caused by the bite of the Aedis aegypti mosquito and mosquito control led to significantly better control of the disease. It was still a considerable problem in places where mosquitoes could not be controlled so a vaccine was created in 1930 which has been very effective in reducing disease. Travelers to parts of South America and Africa are still at risk, as are residents. Unfortunately the vaccine can rarely cause a version of yellow fever in some people and can cause a fatal inflammation of the brain. The newer version of the vaccine is less likely to cause these side effects, but they can still occur. Despite the known side effects, travelers to many countries need to provide proof of vaccination in order to enter if they are arriving from an area with known risk of yellow fever.
The Swine Flu debacle
In 1976 there was an outbreak of swine flu (H1N1 influenza) in Fort Dix, New Jersey. One army recruit died, and there was fear that this virus, which was similar to the one that caused the influenza pandemic in 1918, would spread across the country. In fact, the only infections were at Fort Dix and 40 million Americans were vaccinated against it, resulting in quite a number of cases of Guillain Barre syndrome, an immune mediated paralysis that can result from both infections and vaccinations. On the bright side, apparently immunity from that vaccine did last until the most recent pandemic in 2009, so the folks who got that vaccine were less likely to come down with our most recent H1N1.
Where do we stand, legally?
The laws about vaccinating children differ by state. All states require some vaccinations in order to attend school, but some states offer exemptions, not just on the basis of medical issues such as immune system diseases, but on the basis of parents' religious or philosophical beliefs or values. With the recent measles outbreak, children who did not receive measles vaccination are being kept out of school, and some schools in California have reported up to 65% of students not being fully vaccinated due to their parent's objections. Some suggest more stringent requirements for vaccination, eliminating exemptions on the basis of religious or philosophical beliefs. West Virginia has already taken this step and several other states have only medical and religious exemptions.
Stupid people? Not so fast...
So are "anti-vaxxers" stupid and selfish? I don't think so. At least not necessarily more so than anyone else. Some of their concerns are not really valid, like worrying about the presence of tiny amounts of mercury as a preservative in some vaccines (hardly any now) and the possibility that multiple vaccines given at the same time will overwhelm the immune system (it's actually built for that: picture what happens when a child eats a handful of dirt.) There are some reasonable arguments against vaccinating ones children, even though I may not agree with them. Since vaccination protects the population and because it can be a big money maker for clinics, pharmacies and drug companies, it would not be surprising if we didn't hear much about occasional side effects. So suspicion is not entirely unwarranted. As a loving parent it is hard to be a party to 24 immunizations before the age of 18 months, especially since most of them involve sticking a needle into tender baby flesh. When a disease, like measles, seems to be vanishingly rare, how wise is it to expose one's children to an immunization which definitely has associated side effects (though not autism)? Some of the parents who reasoned in this way now have children with measles and many more have children who aren't able to attend school because they are not vaccinated. Are they selfish? They probably didn't think they were, but the vaccine isn't 100% effective and it isn't given until after a child's first birthday, so infection with measles does put other children, especially babies, at risk of measles and its complications.
Civil discourse--perhaps we should give it a try
How do we, as a society, want to deal with this issue? Americans are fiercely individualistic compared to many other countries, and we usually tell the government that they have no jurisdiction when it comes to our personal decisions. We draw the line (but it's a very wiggly one) at personal decisions that put our children or other people at risk. That's how our rules about vaccination came about in the first place. We, as physicians and nurses, now tell people about side effects of vaccines at the time they are administered, but we don't, in fact, allow them to refuse them for their children unless they also want to opt out of public school, except in the case of religious or philosophical beliefs. Do we want to close those loopholes as well? What we really ought to do is have civil and respectful conversations. We should carefully weigh both the value of controlling vaccine preventable and otherwise untreatable diseases against the actual observed side effects of vaccines. We want to support scrutiny by organizations that have as little vested interest as possible, such as the CDC. We want both sides, vaxxers and anti-vaxxers to avoid black and white thinking.
Yay Vaccines!
I am a big fan of vaccination as a means of fighting disease. It is an ingenious concept. The recipient of a vaccination gets an injection or oral dose of a weakened virus or bacterium or an inactive part of one, which causes the body's own immune system to produce cells that will recognize and kill the real virus or bacterium if it enters the body at some future date. Vaccinations are so much more elegant than antibiotics, which are chemicals that are broadly active against a whole bunch of different agents and only last until the body inactivates or excretes them. Vaccines stimulate the body's own very complex and amazingly effective systems for fighting infection in much the same way that natural infections or exposures would. These systems are then available to prevent disease whenever the need arises.
Herd immunity--that's how vaccines eradicate diseases
Vaccines are ingenious at the individual level, but they are even more ingenious on the level of populations. A vaccine raises an individual's resistance to a disease, but each individual is still somewhat vulnerable to that disease because the body's defenses are not absolute. Some vaccines are more effective than others, and some people have a more robust response than others. Infectious diseases persist in our communities because they move from one person to another. If the vast majority of people in the community are immune to a disease, as can be achieved with vaccination, the disease cannot be transmitted and will die out. The few people in the population who are not immune are protected by the many who are since the likelihood of coming into contact with someone with an active infection in such a community is very low. This effect is known as "herd immunity" and is one of the primary reasons that we should care about whether other people get vaccinated.
Curing smallpox
The word "vaccination" comes from the word root for cow, since the first vaccine in common use was derived from cows to fight smallpox. It had been observed that dairy maids who were infected with cowpox, a pustular disease, from touching the udders of infected cows did not get smallpox. In 1796 the physician Edward Jenner created a vaccine from that virus which became widely used. In 1979 smallpox, which killed as many as 500 million people in the 20th century alone, was declared eradicated. The vaccine was mandatory for school children, and I'm pretty sure I got it when I was a kid. It usually left a little scar on the upper arm but otherwise only rarely had side effects. Once in awhile, when a child had something that predisposed him or her to more serious infections, the vaccination would cause an overall body pustular rash which was very nasty. The vaccine is no longer in common use, but still exists, especially for preventing the tropical disease monkeypox which is similar to smallpox but milder.
Goodbye, polio
Other vaccine successes include polio, which was a virus that primarily infected children via the fecal-oral route, and caused paralysis, which was often fatal or disabling for life. The first vaccine was produced by Dr. Jonas Salk and was an injectable dead virus, and the second, close on its heels, was an oral vaccine that was a live attenuated virus (meaning it resembled the active virus but didn't cause polio.) Polio has been wiped out in most developed countries now due to vaccination, though it still breaks out in countries where vaccination is less common.
Measles, mumps and rubella
The measles vaccine was first licensed in 1962 and improved in 1968. It was combined with vaccines against mumps and rubella to create the MMR in 1971. It is estimated that the vaccine, in its first 20 years, prevented 52 million cases of measles, 17,400 cases of mental retardation due to measles effects on the brain and 5200 deaths. Measles causes fever, runny eyes and nose, a cough, a typical spotty rash and sometimes sore throat and spots in the mouth. I saw a case in Africa in a very miserable infant who probably had measles related pneumonia and had a reasonable chance of dying of the disease. Globally, measles vaccination has had a staggering impact. In the year 2000 it is estimated that over 700,000 people died of measles, primarily children, making it the 5th leading cause of death in kids. With a UNICEF backed measles immunization strategy, measles infections and deaths were reduced by 74% by the year 2010. Africa and India are major measles hot spots. There is no specific treatment for measles, so the only thing physicians can do is support the patient with fluids or oxygen if necessary and try to make sure the disease doesn't spread to others who might be vulnerable. Measles is very contagious. The vaccine, however, is very effective in preventing the disease. Rubella is another spots and fever disease, and can cause serious birth defects if a pregnant mother is infected with it. I had that one when I was a wee child and it didn't seem too bad, but I hope I didn't infect any pregnant people. There was no commonly available vaccine at that time. Mumps is a virus that causes swelling of the lymph nodes and can infect a young man's testicles, sometimes resulting in infertility. The vaccine is quite effective in preventing it, but not nearly as good for mumps as it is for measles.
Autism connection? Nope.
MMR is the vaccine at the center of the present controversy. In 1998 Andrew Wakefield, a gastroenterologist in England, reported 8 cases of children who developed autistic symptoms and gastrointestinal symptoms within 1 month of receiving the MMR vaccine. He proposed that the vaccine was causative, despite the fact that there was no obvious reason why it should be and there was no increase in cases of autism in the period after the MMR vaccine was introduced in England. His data was later questioned and thought to be fraudulent and the paper was retracted. Many studies have been done since then and have not shown any believable evidence that MMR causes autism, yet there are many people who still believe the vaccine/autism connection. Autism does present in early life and vaccines are given in early life, so a reasonable parent with a child who develops autism might suspect that the vaccine caused the autism, even though it did not.
But wait...not necessarily all good
Although it seems pretty clear that MMR doesn't cause autism, vaccines are not all benign and there are many diverse vaccines in common use. In the first 18 months of life the Centers for Disease Control recommends that a child receive about 24 immunizations, if I am reading this chart correctly. If successful, the vaccinations might prevent pneumonia, hepatitis, meningitis, chickenpox and the shingles that can follow in later years, tetanus, which can be fatal, whooping cough, most ear infections and rotavirus gastroenteritis. Also, of course, measles, mumps and rubella. But this is a lot of shots. Each one might cause muscle aches, listlessness and injection site redness and swelling. Children also often cry really hard and want never to go back to the doctor's office. The shot that prevents whooping cough can occasionally cause high fever and seizures and sometimes, though rarely, results in a temporary floppy unresponsive state that can't be a good thing. The reformulated version of this, which has been available for decades now, is less likely to cause these side effects, but the reactions still occur. The rubella part of the MMR can cause chronic arthritis in adults who are rubella immune if they receive MMR to boost their measles immunity.
Other vaccine greats
There are also immunizations for older children and adults which are just as miraculous and just as much of a concern with regard to side effects. These are recommended for various subgroups and situations, but not required for school aged children. This is a list of all of the vaccines available in the US. One of my favorites on this list is the chickenpox vaccination. I must have been an odd and solitary child because I never got chickenpox. My twin got it when she was in her 20s and was really sick. She still has scars from it. Chickenpox is usually an annoying skin rash, with lots of small blisters that scab after a few days, but those little blisters can occur in the mouth and esophagus which makes eating and swallowing very difficult, and the virus can cause severe pneumonia. When I was in my thirties they released the chickenpox vaccine and I got one. Since that time I have been exposed to chickenpox, which is incredibly contagious, many times without getting the disease. This means that I, and the generation of children that have gotten that vaccine will never get shingles, which is a reactivation of chickenpox which causes pain and skin lesions, sometimes with lifelong pain and scarring. Despite the fact that the flu shot is sometimes disappointingly ineffective, I happily submit to it yearly because the flu is such a nasty disease and vaccination lowers my risk of getting it or makes it less severe if I do. The human papillomavirus (HPV) vaccination is also a winner. It is indicated in girls and boys to prevent genital warts that can cause cervical and penile cancer. It is still expensive and hasn't been embraced universally yet, partly because genital warts can also be prevented by having only one sexual partner for life and making sure that he or she has never had sexual contact with anyone else. Some parents forego the vaccine for their children because they believe that this will be achievable. Cervical cancer kills 4000 women yearly and results in fertility threatening surgery and treatments in many more. The HPV vaccine could prevent these outcomes and potentially also make the dreaded pap smear obsolete.
Yellow fever: not without its problems
The yellow fever vaccine is both wonderful and terrible. In the 1600's yellow fever came from Africa to the Americas and eventually to Europe with captured African slaves. Yellow fever is so named because it causes liver failure with jaundice. It also causes nausea, vomiting, kidney failure and diffuse bleeding. It killed more soldiers in the Spanish American war than battle injuries. It slowed work on the Panama canal and infected people in Boston and other US port cities. In the early 1900's it was found to be caused by the bite of the Aedis aegypti mosquito and mosquito control led to significantly better control of the disease. It was still a considerable problem in places where mosquitoes could not be controlled so a vaccine was created in 1930 which has been very effective in reducing disease. Travelers to parts of South America and Africa are still at risk, as are residents. Unfortunately the vaccine can rarely cause a version of yellow fever in some people and can cause a fatal inflammation of the brain. The newer version of the vaccine is less likely to cause these side effects, but they can still occur. Despite the known side effects, travelers to many countries need to provide proof of vaccination in order to enter if they are arriving from an area with known risk of yellow fever.
The Swine Flu debacle
In 1976 there was an outbreak of swine flu (H1N1 influenza) in Fort Dix, New Jersey. One army recruit died, and there was fear that this virus, which was similar to the one that caused the influenza pandemic in 1918, would spread across the country. In fact, the only infections were at Fort Dix and 40 million Americans were vaccinated against it, resulting in quite a number of cases of Guillain Barre syndrome, an immune mediated paralysis that can result from both infections and vaccinations. On the bright side, apparently immunity from that vaccine did last until the most recent pandemic in 2009, so the folks who got that vaccine were less likely to come down with our most recent H1N1.
Where do we stand, legally?
The laws about vaccinating children differ by state. All states require some vaccinations in order to attend school, but some states offer exemptions, not just on the basis of medical issues such as immune system diseases, but on the basis of parents' religious or philosophical beliefs or values. With the recent measles outbreak, children who did not receive measles vaccination are being kept out of school, and some schools in California have reported up to 65% of students not being fully vaccinated due to their parent's objections. Some suggest more stringent requirements for vaccination, eliminating exemptions on the basis of religious or philosophical beliefs. West Virginia has already taken this step and several other states have only medical and religious exemptions.
Stupid people? Not so fast...
So are "anti-vaxxers" stupid and selfish? I don't think so. At least not necessarily more so than anyone else. Some of their concerns are not really valid, like worrying about the presence of tiny amounts of mercury as a preservative in some vaccines (hardly any now) and the possibility that multiple vaccines given at the same time will overwhelm the immune system (it's actually built for that: picture what happens when a child eats a handful of dirt.) There are some reasonable arguments against vaccinating ones children, even though I may not agree with them. Since vaccination protects the population and because it can be a big money maker for clinics, pharmacies and drug companies, it would not be surprising if we didn't hear much about occasional side effects. So suspicion is not entirely unwarranted. As a loving parent it is hard to be a party to 24 immunizations before the age of 18 months, especially since most of them involve sticking a needle into tender baby flesh. When a disease, like measles, seems to be vanishingly rare, how wise is it to expose one's children to an immunization which definitely has associated side effects (though not autism)? Some of the parents who reasoned in this way now have children with measles and many more have children who aren't able to attend school because they are not vaccinated. Are they selfish? They probably didn't think they were, but the vaccine isn't 100% effective and it isn't given until after a child's first birthday, so infection with measles does put other children, especially babies, at risk of measles and its complications.
Civil discourse--perhaps we should give it a try
How do we, as a society, want to deal with this issue? Americans are fiercely individualistic compared to many other countries, and we usually tell the government that they have no jurisdiction when it comes to our personal decisions. We draw the line (but it's a very wiggly one) at personal decisions that put our children or other people at risk. That's how our rules about vaccination came about in the first place. We, as physicians and nurses, now tell people about side effects of vaccines at the time they are administered, but we don't, in fact, allow them to refuse them for their children unless they also want to opt out of public school, except in the case of religious or philosophical beliefs. Do we want to close those loopholes as well? What we really ought to do is have civil and respectful conversations. We should carefully weigh both the value of controlling vaccine preventable and otherwise untreatable diseases against the actual observed side effects of vaccines. We want to support scrutiny by organizations that have as little vested interest as possible, such as the CDC. We want both sides, vaxxers and anti-vaxxers to avoid black and white thinking.
Comments
All that I attempted was to explain the concept of "herd immunity"... and why that works best when the greatest percentage are protected. But this issue of "Freedom" came up... and I was accused of: ignorance; being a dupe of (or shill for) "Big Pharma"; giving in to "the Control Freaks" (eg the Gates Foundation); hating 'innocent babies'(???); and more.
I also had positive feedback... and a few conversations got beyond the 'venting' stage. What began to sink in was that: the 'unknown' was a strong deterrent to parents' lack of willingness to vaccinate their kids; the "propaganda" factor was Huge (and pervasive); and this 'libertarian' behavior- of wanting to "cherry-pick" what worked for THEM- and still take advantage of 'our Freedoms' without any concomitant 'Responsibility' for their choices was very prevalent.
I home-schooled my children for a few years... but took advantage of the local "well child" clinic to immunize my kids, in the '70s (having also delivered them at home, unaided). "Freedom" is fine... if you think it through, and understand that we All breathe here, together-- you, me, & the automobiles & trucks, etc. The gas additives are 'here', too... and there's no 'Freedom' from that, without a mask. Every person in the N. Hemisphere (and polar bears, too) have "fire retardants" in their systems (body fat, etc). I'd be FAR more concerned with the proliferation of halogenated hydrocarbon compounds in the environment than I would be for 'side effects' to vaccines.
I may be a little less enthusiastic about some of the current menu of available immunizations, especially "all at once", to the very young... but those "basic"- and proven- categories are worth tamping down one's ideas of "Freedom" (and the "exceptionalism" that always seems to emanate from those expressions). Hey- we're all animals, and we're in this together (on so many levels)... and the viruses, etc are, too... and have WAY more experience than WE do. (And, thanks for the link to the MMR Wiki... which I'm gonna go & read, right now.) ^..^