This is a bit different from my usual style, but a friend of mine on Facebook posted a link to a blog called "Measles Shmeasles Goes to Disneyland" by someone named Jessica Gianelloni, and asked for my input/opinion about what it said, and I put a lot of work into putting together a response, so I figured I might as well post it here too. Note: The original blog no longer exists, as the owner shut it down for some reason, but the content can probably still be found online if you desire it.
Overall I think in this article Jessica gets a bunch of stuff wrong, and at least some of the things she gets right are badly out of context. An interesting thing to note is that I searched for the headline she cites ("Disneyland Measles Outbreak Linked To Anti-Vaccine Movement") and could only find it on The Onion. Make of that what you will.
One thing that seems correct is that the vaccine is not as effective as expected in the 1960s; one dose is not adequate. I don't know why Jessica says 3 or more doses are recommended now though; all the recommendations I could find said only two. But that's not super-important at this point.
HERD IMMUNITY
The next thing is a claim that at least 80% of people being immune is required for herd immunity, which seems accurate based on her "citation." And levels are even higher than that, around 90% vaccinated; I doubt this is incorrect. The question is that if we have such high coverage, which is predicted to prevent spread of measles, why do we have measles outbreaks? And the implication is that the vaccine must not be capable of preventing the spread.
This is a very unsophisticated analysis though. Measles is considered eradicated in the US, which doesn't mean there are no cases, but it means that any outbreaks that start are imported from other countries; once a given outbreak ends, the virus is not present in that area anymore to start any more outbreaks.
And when outbreaks do happen, it's pretty consistent that a majority of the cases are people that never had a measles vaccine; there are areas where the coverage is well below 80% of people. For examples: there was a study on outbreaks from 1989 to 1991, and the risk of catching measles was 35 times higher for unvaccinated people. In 1990 for example, unvaccinated people made up 0.5% of the population but had 17% of the cases of measles in the outbreak. That's a lot higher than would be expected if the vaccine weren't very good. This number was worse in some years, better in others.
In the current Disneyland outbreak, of 34 cases in which the vaccination status of the people was known, 28 hadn't been vaccinated (82%). Similarly, in outbreaks in the first half of 2013 and 2014, of those cases with known vaccination status, 91% and 87% (respectively) were known to be unvaccinated. Only 2% of cases in the 2013 data had received both recommended doses. So it's not really possible to say these were outbreaks in highly vaccinated populations, since it spreads mostly only between unvaccinated. This is something Jessica seems to get wrong.
One thing to note is that of those unvaccinated cases, some of them were too young to be vaccinated. This is important in light of Jessica's Palevsky quote: the reason people who vaccinate are upset with those who don't is that when outbreaks occur, it's mostly the unvaccinated that spread disease to those too young to be vaccinated.
NATURAL MEASLES IS NICE
Next is claims about how before there was a vaccine, measles was a one-time thing, a normal part of growing up, and even contributed to a person's health in many ways other than just the disease itself. But now the vaccine makes it so that instead of measles being found mostly in older children (where it is mildest), it's more common in young children (too young to be vaccinated). The numbers Jessica gives are from less than 0.5% of cases in infants before the vaccine, to 30% now. In addition, implications are that the vaccine A) does not allow mothers to pass protective antibodies to their infants, at least not as well; B) does not offer life-long protection; and C) does not provide the same alleged general health benefits as actual measles infection.
First, about epidemiology before and after the vaccine: I don't know where Jessica got these numbers, but they aren't nearly in line with what I could find. First, from a couple of studies in the US in the 1930s, that I've blogged about before: One in Detroit in 1935 (081) found that in children 0-9 years old, 6% of cases were in children under 1 year old (and 66% in 1- to 4-year-olds). The other, in 1930 in Baltimore (060) found that of cases in children 0-14 years old, 4% were in under 1 year, 8% in 1 year, and most in 1-8 years old. So that's a lot higher than under 0.5%, long before the vaccine.
In more recent outbreaks: In the Disneyland outbreak so far, 6% of the cases have been infants under 1 year old. Again in the first half of 2013, 11% of the cases were under 1 year old. So that's a bit higher than the 1930s numbers, but nowhere near the 30% that Jessica claims.
It's also worth mentioning that in the population overall, in the 1930 Baltimore study, 0.8% of children under 1 year old got sick with measles; so 8 per 1000. Compare that to today, in the 1st half of 2013, there were 18 cases in children under 1 year out of a nationwide population of about 4 million in that age range; so that's 0.0009% of infants got measles. That's 9 per million, almost 1000 times less than before the vaccine. And Jessica acknowledges that the seeming 98% decline in measles was the death rate, not the incidence rate ("Does the incidence rate when the vaccine was introduced even matter?"), so we can attribute this 1000-fold decrease to the vaccine. That seems pretty impressive. I would say, is it important that a slightly higher proportion (2x) of outbreak cases are in younger children, if younger children are much less likely (1000x) to catch it overall?
Next, implication A: the vaccine does not allow mothers to pass protective antibodies to their infants, at least not as well the actual disease. Mothers who had the natural infection pass antibodies to their infants that generally protect them for 12-15 months (as Jessica says). But studies show that mothers who only had the vaccine can also pass protective antibodies to their infants. In this 2010 study, the protection passed from vaccinated mothers to infants was similar to that from naturally immune mothers, though it faded a bit more quickly (1-3 months less time). Here is a nice graph from this study:
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| Leuridan 2010, Figure 2 |
Is this significant? Probably somewhat, but not nearly as big a difference as Jessica makes it sound, and measles is a lot more rare now too.
Next, implication B: the vaccine does not offer life-long protection like the actual disease. I didn't look too hard into the claim that the wild virus provides life-long immunity (though one of the first detailed accounts of measles did include an observation of someone who seemed to still be immune to measles after having caught it 60 years earlier. No idea if that is a common thing though). As for the vaccine, a 2012 study found that after 20 years, only 10-15% of people who had received 2 doses had no antibodies. There was also a 1998 study that found that after 12 years, about 98% of people who got the vaccine seemed to have adequate antibody levels to protect them.
At this point in my writing, Jessica shut down her blog. Not sure why. Luckily I found another copy online so I can continue to go back and see what she said.
Next, implication C: the vaccine does not provide the same alleged general health benefits as actual measles infection. Immune diseases, tumors, allergies? I think I know what she's talking about here, something I had heard of before: there was a 1985 study that compared children who got measles and either had a rash or didn't have a rash. There wasn't any comparison with vaccinated or anything, just measles infections. And it seemed to show that children who got the rash had fewer health issues later in life than those who didn't. The lack of rash was explained by children having some sort of passive immunity, either from maternal antibodies or from injections of antibodies; there was no discussion about how the vaccine might affect things. But the hypothesis was that if the body didn't completely deal with the virus all at once, the virus might lurk around and cause health problems later (the ones Jessica claims it prevents). But I don't know if there was any follow-up to this study to clarify anything.
As it stands, it seems like the vaccine might be just as helpful as full-blown measles in preventing these health issues. Other research in Africa found that "vaccine efficacy against death was much greater than the proportion of deaths attributed to acute measles disease...These observations suggest that standard titre measles vaccine may confer a beneficial effect which is unrelated to the specific protection against measles disease." And another study found maybe a slightly increased risk of allergy for those who got wild measles infections.
Overall, it doesn't seem like the data supports Jessica's claims and implications.
MEASLES IS NOT NECESSARILY DANGEROUS
Jessica then claims that measles is not something to be feared, at least not in developed countries such as the US, so a vaccine is not necessary. And even in developing countries such as Africa, the vaccine is not as helpful as sanitation and nutrition would be, especially vitamin A. The implication, I think, is that the costs and risks from the vaccine are greater than the benefits, compared to other treatments or the disease itself.
I'll address the costs and risks of measles first. The CDC in 1998 claimed that measles kills 1 or 2 people for every 1000 it infects, and this is about the same rate as for the encephalitis it causes, a serious brain inflammation. In developing countries, it can kill as many as 1 out of 4 people it infects. I don't know where these numbers come from though.
For encephalitis, I didn't find any other good numbers on that, but it seems like we haven't seen any for a while. However, you can see in the outbreaks I've cited above (Disneyland, 2013, 2014), at least 11% of those who caught it needed to be hospitalized; up to 25% sometimes. Seems pretty serious. I guess I can appreciate Jessica's faith in modern medicine, though, if she thinks being hospitalized is no big deal.
As for death rates, two people died from measles in 2003, and considering the number of cases since 2000, about 1500, that's right in the 1-2 per 1000 range. The two deaths weren't exactly in the healthiest people, but unhealthy people do exist (often through no fault of their own) and should be protected; also, it's not always possible to know who is particularly susceptible to the disease. It could be you!
Another confirmation of the death rate: in the 1999 study mentioned above, there were 26672 cases and 89 deaths. This works out to 3 per 1000 cases; right on target, unfortunately.
But risk of death is not the only factor to consider; there's also cost burden, both to individuals and to the healthcare system overall. Being hospitalized is not cheap, I'm pretty sure, especially for those who have no insurance. A study estimated that each case of measles costs about $20,000 (and that's a conservative estimate!). This is costs for treatment and also public health efforts to track and control the outbreaks. Definitely a cost worth avoiding if possible.
What about vitamin A? That's a fairly cheap and low-risk treatment, right? I don't know what African study Jessica is referring to in the blog, of course, but the World Health Organization agrees that it's worth giving vitamin A to people with measles in developing countries, and agrees with Jessica's 50% figure. A review of other studies concludes that vitamin A might help reduce severity, at least in hospitalized cases. So that's nice, though I don't know how much of an impact it could really have on the risks overall. It seems better to avoid being hospitalized and needing treatment in the first place.
So overall, a fairly high risk of hospitalization (and associated costs), a fairly low (but not negligible) risk of death, perhaps less risk with vitamin A treatment, at least in developing countries. The obvious next question: is the vaccine any better, or is it worse?
THE MEASLES VACCINE IS MORE DANGEROUS
Jessica claims that the vaccine is associated with "seizures, encephalitis, blood disorders, sensory impairments, learning disabilities, immune system suppression, inflammatory bowel disease, inflammation of the brain, and many other severe allergic reactions." Some of those are redundant or too vague for me to figure out what she's talking about, but the Institute of Medicine released a report a few years ago reviewing vaccines and the evidence for their risks, so I'll summarize some of that.
Keep in mind that, for measles itself, if we didn't have a vaccine, there would be about 500,000 to 5 million cases in the US each year, so with a 1 in 1000 to 1 in 10000 death rate (I'm being conservative, giving a range), that means 50 to 5000 deaths and 55000 to 750000 hospitalizations. Are vaccines worse than that?
Regarding encephalitis/brain inflammation, there were studies looking at more than 500,000 children. In that sample, 199 got encephalitis, which overall is about 4 in 10000, except that only 9 of those cases happened within 3 months of vaccination; 80 of them were actually before the children got vaccinated, and the rest were more than 3 months after. So hardly any were likely associated with the vaccine. Another study found no association either.
Regarding febrile seizures, the report concluded evidence was pretty good that they were associated with the vaccine, but they don't seem to cause any permanent harm or learning disability.
Next, implication B: the vaccine does not offer life-long protection like the actual disease. I didn't look too hard into the claim that the wild virus provides life-long immunity (though one of the first detailed accounts of measles did include an observation of someone who seemed to still be immune to measles after having caught it 60 years earlier. No idea if that is a common thing though). As for the vaccine, a 2012 study found that after 20 years, only 10-15% of people who had received 2 doses had no antibodies. There was also a 1998 study that found that after 12 years, about 98% of people who got the vaccine seemed to have adequate antibody levels to protect them.
At this point in my writing, Jessica shut down her blog. Not sure why. Luckily I found another copy online so I can continue to go back and see what she said.
Next, implication C: the vaccine does not provide the same alleged general health benefits as actual measles infection. Immune diseases, tumors, allergies? I think I know what she's talking about here, something I had heard of before: there was a 1985 study that compared children who got measles and either had a rash or didn't have a rash. There wasn't any comparison with vaccinated or anything, just measles infections. And it seemed to show that children who got the rash had fewer health issues later in life than those who didn't. The lack of rash was explained by children having some sort of passive immunity, either from maternal antibodies or from injections of antibodies; there was no discussion about how the vaccine might affect things. But the hypothesis was that if the body didn't completely deal with the virus all at once, the virus might lurk around and cause health problems later (the ones Jessica claims it prevents). But I don't know if there was any follow-up to this study to clarify anything.
As it stands, it seems like the vaccine might be just as helpful as full-blown measles in preventing these health issues. Other research in Africa found that "vaccine efficacy against death was much greater than the proportion of deaths attributed to acute measles disease...These observations suggest that standard titre measles vaccine may confer a beneficial effect which is unrelated to the specific protection against measles disease." And another study found maybe a slightly increased risk of allergy for those who got wild measles infections.
Overall, it doesn't seem like the data supports Jessica's claims and implications.
MEASLES IS NOT NECESSARILY DANGEROUS
Jessica then claims that measles is not something to be feared, at least not in developed countries such as the US, so a vaccine is not necessary. And even in developing countries such as Africa, the vaccine is not as helpful as sanitation and nutrition would be, especially vitamin A. The implication, I think, is that the costs and risks from the vaccine are greater than the benefits, compared to other treatments or the disease itself.
I'll address the costs and risks of measles first. The CDC in 1998 claimed that measles kills 1 or 2 people for every 1000 it infects, and this is about the same rate as for the encephalitis it causes, a serious brain inflammation. In developing countries, it can kill as many as 1 out of 4 people it infects. I don't know where these numbers come from though.
For encephalitis, I didn't find any other good numbers on that, but it seems like we haven't seen any for a while. However, you can see in the outbreaks I've cited above (Disneyland, 2013, 2014), at least 11% of those who caught it needed to be hospitalized; up to 25% sometimes. Seems pretty serious. I guess I can appreciate Jessica's faith in modern medicine, though, if she thinks being hospitalized is no big deal.
As for death rates, two people died from measles in 2003, and considering the number of cases since 2000, about 1500, that's right in the 1-2 per 1000 range. The two deaths weren't exactly in the healthiest people, but unhealthy people do exist (often through no fault of their own) and should be protected; also, it's not always possible to know who is particularly susceptible to the disease. It could be you!
Another confirmation of the death rate: in the 1999 study mentioned above, there were 26672 cases and 89 deaths. This works out to 3 per 1000 cases; right on target, unfortunately.
But risk of death is not the only factor to consider; there's also cost burden, both to individuals and to the healthcare system overall. Being hospitalized is not cheap, I'm pretty sure, especially for those who have no insurance. A study estimated that each case of measles costs about $20,000 (and that's a conservative estimate!). This is costs for treatment and also public health efforts to track and control the outbreaks. Definitely a cost worth avoiding if possible.
What about vitamin A? That's a fairly cheap and low-risk treatment, right? I don't know what African study Jessica is referring to in the blog, of course, but the World Health Organization agrees that it's worth giving vitamin A to people with measles in developing countries, and agrees with Jessica's 50% figure. A review of other studies concludes that vitamin A might help reduce severity, at least in hospitalized cases. So that's nice, though I don't know how much of an impact it could really have on the risks overall. It seems better to avoid being hospitalized and needing treatment in the first place.
So overall, a fairly high risk of hospitalization (and associated costs), a fairly low (but not negligible) risk of death, perhaps less risk with vitamin A treatment, at least in developing countries. The obvious next question: is the vaccine any better, or is it worse?
THE MEASLES VACCINE IS MORE DANGEROUS
Jessica claims that the vaccine is associated with "seizures, encephalitis, blood disorders, sensory impairments, learning disabilities, immune system suppression, inflammatory bowel disease, inflammation of the brain, and many other severe allergic reactions." Some of those are redundant or too vague for me to figure out what she's talking about, but the Institute of Medicine released a report a few years ago reviewing vaccines and the evidence for their risks, so I'll summarize some of that.
Keep in mind that, for measles itself, if we didn't have a vaccine, there would be about 500,000 to 5 million cases in the US each year, so with a 1 in 1000 to 1 in 10000 death rate (I'm being conservative, giving a range), that means 50 to 5000 deaths and 55000 to 750000 hospitalizations. Are vaccines worse than that?
Regarding encephalitis/brain inflammation, there were studies looking at more than 500,000 children. In that sample, 199 got encephalitis, which overall is about 4 in 10000, except that only 9 of those cases happened within 3 months of vaccination; 80 of them were actually before the children got vaccinated, and the rest were more than 3 months after. So hardly any were likely associated with the vaccine. Another study found no association either.
Regarding febrile seizures, the report concluded evidence was pretty good that they were associated with the vaccine, but they don't seem to cause any permanent harm or learning disability.
Regarding autism, there have been a lot of studies of that with the MMR, some better and some worse. Even of the better ones, they're consistent with their reporting of a lack of association of the vaccine with autism.
Not sure what Jessica means by "blood disorders," but studies consistently report a lack of association of the vaccine with type 1 diabetes at least.
For sensory impairments and other things, the report authors considered the link between measles itself and the vaccine as some evidence for an association, but other than that there wasn't good evidence for a link with the vaccine in particular.
For allergic reactions, there is good evidence that the vaccine is associated with anaphylaxis, but this is rare, happens right after the shot, and is treatable.
Considering all that, it seems pretty clear that we aren't aware of any reason why the vaccine should be considered more risky than measles itself for most people. And it's pretty clear from recent outbreaks that we need to choose one or the other. So those are my thoughts on the issue, based on the data I could find. Just the facts.
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