Is the comeback of measles in the US "largely due to anti-vaxers?"

Question

From CNN:

In some recent years, there have been fewer than 100 cases nationwide. But the [measles] virus has made a comeback in other years, including 2019 -- largely due to anti-vaxers, experts say.

The article doesn't include any statements by any "experts" mentioning anti-vaxers.

Is the comeback of the measles virus "largely due to anti-vaxers?" Have other sources made a similar attribution?

Why don't I believe CNN? Its claim makes sense, right? Well, the Oxford Vaccine Group at the University of Oxford wrote (emphasis added):

People who oppose vaccination – the so-called “anti-vaxxers” – are often thought to be the reason for low vaccination rates. The truth is, anti-vaxxers don’t wholly explain low vaccination rates. The influence of the movement is often exaggerated and does not properly explain a complex situation.

So, is CNN's claim an exaggeration? Or is it the reality?

To clarify (as @redleo95 suggested): The accepted answer has to include data on anti-vaxxers.

To clarify (as @Fizz suggested): It is preferred if the accepted answer focuses on the US (and specifically, the 2019 measles outbreak).

Who are anti-vaxxers? (suggested by @redleo95 and only partially addressed in comments): Consider 1) "people/groups who possess an anti-vaccine sentiment" and/or 2) "people/groups who possess and actively advocate an anti-vaccine sentiment."

@fredsbend Good point. The lack of reputable sources is another reason I want to find out more. Any answer that teaches me something would be great. — Barry Harrison, Apr 21 '19 at 03:30
Coincidentally, I just heard a claim from Andrew Wakefield of all people, in person if you'll believe it, that the comeback is due to measles being unique in its mutations. In other words, he suggests that the vaccination is setting us up for serious pandemic. Considering the source, take it with a grain of salt. — , Apr 21 '19 at 03:32
@fredsbend Interesting! I will still look into measles and its mutations, won't hurt. — Barry Harrison, Apr 21 '19 at 03:33
@fredsbend curious. I've heard that influenza mutates like crazy - which is why you need a new vaccine each year and it's still a crapshoot - but I've never heard such of measles. OTOH, I've heard that measles were pretty much non-existent before the anti-vaccination craze. — John Dvorak, Apr 21 '19 at 08:55
The two statements are not necessarily mutually exclusive. As I understand it CNN is referring to an increasing number of outbreaks in the last few years. The Oxford Vaccine Group is referring to vaccination rates (probably of the whole country). Anti-vaccine groups have limited influence on vaccination rates country wide, because they are relatively few, but at the same time have bigger influence on individual outbreaks, because inside a given community they my have a large influence on vaccination rates. — redleo85, Apr 21 '19 at 12:42
"The truth is, anti-vaxxers don’t wholly explain low vaccination rates." This is obfuscating things. What's happened of late is that anti-vaxxers have become more vocal, in large part due to internet conspiracy sites. But they've been around for decades, haranguing people in churches, etc. — Daniel R Hicks, Apr 21 '19 at 13:49
@JohnDvorak To be honest, I wasn't paying close attention, so I may be misrepresenting him, but he definitely thinks it will get worse and anti-vax positions has little to do with it. — , Apr 21 '19 at 14:51
@redleo85 If your comment is what you supported with evidence, that the influence of anti-vaxxers are localized in regions where the measles outbreak occurred, I will definitely upvote it. Of course, correlation isn't causation, but it's more correlation than your current answer. — Barry Harrison, Apr 21 '19 at 16:43
The question could be improved by giving a proper definition or more explanation of what you consider to be "anti-vaxxers". — redleo85, Apr 21 '19 at 17:03
@redleo85 "people/groups who possess an anti-vaccine sentiment." — Barry Harrison, Apr 21 '19 at 17:06
@Barry You will most likely not get an answer to that question, because you would need hard figures on the number of people with "anti-vaccine sentiment". I doubt these numbers exist anywhere. — redleo85, Apr 21 '19 at 17:11
In the original question, there's the statement "Have other sources made a similar attribution?" Thus, find other statements by experts! — Barry Harrison, Apr 21 '19 at 17:16
If you meant to ask only about the US, please edit your question accordingly, including the title, and add a country tag. Also, the Oxford/Medium page is NOT strictly about the US. So using to "contradict" CNN is a little odd. The former source cites [a Canadian study](https://globalnews.ca/news/3409038/whos-really-to-blame-for-canadas-falling-vaccination-rates-its-not-only-anti-vaxxers-report-says/) for instance, and also discusses Ukraine. — Fizz, Apr 23 '19 at 06:00
@Fizz I tend to interpret the Oxford page as a more general thing. — Barry Harrison, Apr 23 '19 at 06:26
The thing to check would be to compare the number of measles/mumps/chicken pox outbreaks in a state or country whose levels of vaccinations have not been affected by the anti-vax movement/sentiment. Find that state or country and the link as to whether there are outbreaks due to mutation of the virus or because fewer people are being vaccinated will be clearer. While vaccination is obligatory in Italy, Poland and in France, not every parent feels comfortable with the law and complies.... https://www.vaccinestoday.eu/stories/mandatory-vaccination-work-europe/ — Mari-Lou A, May 07 '19 at 08:35
@Mari-LouA Interesting thought! If you answer with that, I will award a 100 rep bounty and upvote it. — Barry Harrison, May 08 '19 at 00:19

score 25 · Accepted Answer · edited May 05 '19 at 21:01

25

The answer depends a lot on what mechanism you imply and who you consider to be "anti-vaxxers". If you consider anti-vaxxers to be all groups of people who as a group oppose vaccination (e.g. for political, religious or other reasons), then CNN is largely right.

If you are looking for a causal link between the anti-vaccination movement and the increasing number of measles cases, it will be hard to prove. Mainly, because no data is collected on why people who get infected did not get vaccinated beforehand. It's also hard to know the number of people who don't get vaccinated because of this movement (people may not get vaccinated for a variety of reasons).

However, the Center for Disease Control (CDC) publishes yearly figures on measles cases in the United States. These are the figures from 2010-2019. The CDC also published information to some of the outbreaks. There are three years with exceptionally high numbers of cases: 2014, 2018 and 2019. In 2014 and 2018 the majority of measles cases occurred in a small number of outbreaks in pockets of largely unvaccinated communities. 2014: 383 cases in the unvaccinated Amish Community, 2018: most of cases in the Jewish-orthodox community in NY State, NYC and New Jersey. For 2019, no specific reason has yet been given. One of the newest studies dealing with vaccine hesitancy and measles Papachrisanthou et al. conclude:

VPDs are on the rise in the US and worldwide secondary to parental misconceptions, vaccine hesitancy, waning immunity, and negative effects on herd immunity.

Olive et al. find that NMEs (non-medical exemptions) for children are on the rise in 12 of 18 states, who permit these exemptions..

Marti et al. look for global reasons for vaccine hesitancy and find that:

The most frequently cited reasons for vaccine hesitancy globally related to (1) the risk-benefit of vaccines, (2) knowledge and awareness issues, (3) religious, cultural, gender or socio-economic factors.

An overview of the reasons can be seen in this graphic

So the one of the main criticisms of the anti-vaxxer movement (risk of vaccines) is the biggest driver of vaccine hesitancy globally.

This influences the US, because international travelers carrying the virus come to the US and infect people in regions where the vaccination rate is low (Papachrisanthou et al.).

The majority of the 2018 measles outbreaks have been in unvaccinated individuals exposed to international travelers. Europe is also experiencing the highest measles outbreak in over 2 decades secondary to suboptimal vaccination rates.

As for expert opinion on a link between anti-vaccination and measles outbreaks: The WHO clearly states in this report,

Because of low coverage nationally, or pockets of low coverage, multiple WHO regions have been hit with large measles and diphtheria outbreaks causing many deaths.

Furthermore, the WHO has included vaccine hesitancy as one of the 10 threats to global health in 2019.

So CNN's claim is not an exaggeration. It depends, though, on who you consider to be "anti-vaxxers". If you include people who do not vaccinate for religious reasons in the anti-vaxxers, CNN is right. If you only include people who do not vaccinate because they believe conspiracy theories that vaccines are harmful to be anti-vaxxers, their influence is plausible, but it is difficult to prove causation.

edited May 05 '19 at 21:01

Glorfindel

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answered Apr 21 '19 at 15:07

redleo85

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"Armish" or did you mean "Amish?" The Amish is a large religious community in the USA. I've never heard of "Armish." – JRE Apr 21 '19 at 16:24
Spelling error. Thank for noting. – redleo85 Apr 21 '19 at 16:28
While I do appreciate the answer, I don't feel it is complete. You mention 2 sources. (1) You associate 2 outbreaks with unvaccinated populations (from CDC data, I don't dispute this). However, were the populations unvaccinated *due to antivaxxers*? (2) The WHO quote doesn't really add anything to your answer. It doesn't mention anti-vaxxers. All it says is lower vaccine coverage can lead to outbreaks. Again, I don't doubt this. But the question is more "Are anti-vaxxers responsible for lower vaccine coverage now than, say, 10 years ago?" than "Is lower vac coverage associated with outbreaks?" – Barry Harrison Apr 21 '19 at 16:39
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Then it would probably help if you specified your answers and your interpretation of the CNN quote you mention. Especially you should specify who you include in "anti-vaxxers" and what kind of mechanism exactly you interpret "largely due to" to mean. As I wrote in the first paragraph, an answer might be impossible. – redleo85 Apr 21 '19 at 16:45
@redleo85 Agreed. However, you drew a relatively definite conclusion: " CNN is largely right." – Barry Harrison Apr 21 '19 at 16:46
If you, I don't know, point out *only* that it's hard to draw a conclusion rather than make a relatively bold unsupported claim, I'd be more OK. – Barry Harrison Apr 21 '19 at 16:47
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But the number of people who do not vaccinate for religious reasons has remained fairly constant (and small) for a long time. The increase in unvaccinated people has been almost entirely due to anti-vax conspiracy theorists, and it is the increase that has caused the measles outbreaks. So it entirely reasonable to state the the outbreak is due to conspiracy-theory anti-vaxxers, even though there are also religious anti-vaxxers in the mix. – DJClayworth Apr 22 '19 at 01:00
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I am *very* hesitant to accept this question for reasons in the comments: (1) a bit too much speculation with a bit too definitive conclusion (there's only 1 source of numeric data!! That's way too few datapoints. More sources please?), (2) doesn't address the 2019 case, (3) doesn't really contain "expert opinion" (WHO link doesn't mention apprehension of vaccination or other anti-vaxx stuff. **So, community: Should I accept this answer?** Before posting any of my questions, I do some "background search." In this case, the answer hasn't taught me anything my background search didn't. – Barry Harrison Apr 22 '19 at 21:50
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@BarryHarrison The WHO document doesn't look like it's a peer reviewed publication. In important questions of public health I don't think answers that don't cite peer-reviewed publications should be "accepted answers" on skeptics.SE. – Christian Apr 25 '19 at 11:29
@Christian I have unaccepted. Many of my above comments detail why I am hesitant to accept this answer. Yet it's so highly upvoted that I doubt anybody else will bother to provide a better answer :( – Barry Harrison Apr 25 '19 at 21:09
I still think the question could be improved instead of setting the bar for an answer higher and higher. Asking for peer-reviewed studies which include numbers from 2019 in April of 2019 effectively makes it impossible to write an answer that can be accepted, because of the length of the peer-review publication process. – redleo85 Apr 26 '19 at 10:05
@Christian I have included a number of peer-reviewed papers to support the argument. I also think questions of public health need to be thorough, but the question as I understand it is less about public health (are vaccines effective), but more about the influence of a small, very vocal minority on the behavior of the greater public. An additional focus is the credibility of CNN. – redleo85 Apr 26 '19 at 10:08
@redleo85 I apologize for "setting the bar for an answer higher and higher." I do not want to be like this and agree that expectations of an answer should be clearly stated in the question or a comment below the question. This was not the case (my bad!). You can stop worrying about your answer. As new sources come up, I'll edit it as needed. – Barry Harrison Apr 26 '19 at 10:24
@Barry No need to appologize. We all want a high quality answer. I just think that some of the restrictions will make it less likely than an additional answer will be provided. – redleo85 Apr 26 '19 at 10:42
@redleo85 Again, lack of clarity *is* a fault on my part. – Barry Harrison Apr 26 '19 at 11:06
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@redleo85 : As the skeptic community I think we should uphold certain epistemic standards. We should especially uphold those standards when interfacing with a community like that of antivaxxers. The question of why we have a comeback of measles is an important question of public healthy whose studies is worthy of grants that fund it and we should be open about the absence of serious scientific investigation of that claim if there's in fact such an absence. – Christian Apr 26 '19 at 12:15
Marti et al. included the category "communication and media environment." I would argue that this category is more characteristic of the anti-vaxx movement. What do you think? – Barry Harrison Apr 26 '19 at 22:16
Depends on how you characterise the anti-vaxx movement. I'm not sure how communication and media environment is characteristic for it. Can you elaborate on that? – redleo85 Apr 27 '19 at 06:04
People who "actively advocate" use communication, yes? Hmm, I now thing this spans the "communication and media environment" category as well as the one right above it. – Barry Harrison Apr 27 '19 at 09:11
@redleo85 Could we have a discussion in chat? Seeing how there probably won't be another answer, I just want to talk over some stuff before I accept. – Barry Harrison May 07 '19 at 01:45
@Barry sure. Give me a time. – redleo85 May 08 '19 at 07:18
@redleo85 OK, will wait then. – Barry Harrison May 08 '19 at 15:19

Barry Harrison · Answer 2 · 2019-04-23T22:35:42.493

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This answer only covers the second question:

Have other sources made a similar attribution?

The Dean for the National School of Tropical Medicine at Baylor has said on twitter (emphasis added):

More bad news...a totally unnecessary and self inflicted wound, and a direct consequence of an aggressive #antivax misinformation campaign

The New York City Health Commissioner has said

This outbreak is being fueled by a small group of anti-vaxxers in these neighborhoods. They have been spreading dangerous misinformation based on fake science.

Additionally, the World Health Organization has placed vaccine hesitancy, defined as "the reluctance or refusal to vaccinate despite the availability of vaccines", on its list of "Ten threats to global health in 2019".

edited Apr 23 '19 at 22:35

answered Apr 21 '19 at 17:10

Barry Harrison

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Community wiki, so anybody can improve the answer. It's not entirely convincing right now. – Barry Harrison Apr 21 '19 at 17:24
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I'd say it's not an answer at all, but merely a statement by one person (albeit someone who likely has better information on the issue than most). – jwenting Apr 23 '19 at 06:44
@jwenting Thanks for the comment. The Q was: "Is the comeback of the measles virus "largely due to anti-vaxers?" Have other sources made a similar attribution?" I guess "other sources with similar attribution" might count. If you want me to delete this, let me know. – Barry Harrison Apr 23 '19 at 06:45
Your attempt at an answer covers the second part of the question, but not the first, I think. You probably should leave it as an avenue for further research or expand on it by digging into the sources used by these people to make their statements. – jwenting Apr 23 '19 at 07:07
@jwenting I will edit to make this clearer. – Barry Harrison Apr 23 '19 at 22:34

Is the comeback of measles in the US "largely due to anti-vaxers?"

2 Answers2