Map(s) of the week: School vaccinations

Toronto is facing its worst outbreak of measles in 12 years, with 21 cases since the middle of March. We’re kicking off the Map of the Week project (introduction here) with four maps dealing with vaccination of students in Toronto schools. An important part of the package is parentcentral.ca editor Brandie Weikle's explanation of why many Toronto students don't have the shots otherwise required by law, and what that could mean.

All images are clickable links. 

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Map: Percentage of the school-aged population (5-18) with vaccination exemptions

As we can see, vaccination exemption is highest in M5J, the FSA that covers the Islands and an area of waterfront condos. It is also high in Bloor West Village/Swansea, High Park, the area south of the Annex to the lakeshore, Seaton Village/Hillcrest, Riverdale and the Beaches, Weston, and the Finch/Bathurst area.

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Schools with the highest percentage of pupils with vaccination exemptions: Top 25

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Schools with the highest number of unvaccinated pupils: Top 25

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Schools with the lowest vaccination rates

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Nerd box

The two starting points for this project were two spreadsheets released by Toronto Public Health under access-to-information laws. One showed vaccination statistics for 861 Toronto schools, and the other gave enough address information of students whose parents have gone through the process of exempting them from vaccination that we could map exemption by neighbourhood, more or less.

The polygons on the first map are postal forward sortation areas (FSAs), the first three digits of a postal code. The amalgamated city of Toronto has just over a hundred, though not all are residential. FSAs are a useful unit for building this kind of map – they’re small enough to yield a lot of local information, while at the same time officials handling the FOI request can’t reasonably argue that anyone’s privacy is being compromised.

Comments

[Bannination]

A legend would be very helpful on the first map so we knew what the heck we are looking at.

[Patrick Cain]

Click on the image to find the full map.

[Peppy Epi]

As an infectious disease epidemiologist, these maps make me want to punch some affluent parents. Don't wanna support herd immunity? Then GTFO of my herd!

[Mother of an Child Who is No Longer Vaccinated]

I tend to find this data pretty useless in general though it is interesting to look at it.

Children are unvaccinated for a variety of reasons some of which maybe:

Reason of Conscious
Freedom of Religion
Medically Contradicted
Previous Adverse Event

Children that are VACCINATED also "shed" when vaccinated with live viruses (for example chicken pox).

I've been through two CP outbreaks in a childcare setting from the vaccinated strain as confirmed by Toronto Public Health. In this instance vaccinated children were shedding and passing on CP. Not the unvaccinated.

Further, the fact that one is unvaccinated does not make them a "host" for disease - DD's been exposed to pertusiss twice and not contracted it.

Just because you are not vaccinated does not guarantee you will become ill with a disease when you encounter it - maybe/maybe not - depends on your overall health, strength of your immune system, etc and what sort of immunity may have been passed to the child across the placenta or via full-term breastfeeding.

For example, an unvaccinated child exposed to the chicken pox may or may not get it. It's not given you will get a disease just because of the "un"vaccination status.

Add on top of this that some vaccines have "low efficacy rates", and certain individuals will experience "primary and secondary failure". Primary being the vaccine just did not work, secondary being waning immunity (Mumps in Iowa is a recent example) which usually leads to the addition of boosters on the schedule - further people's immunity will "wane" at different rates. So even when you have a vaccinated population - their levels of immunity are all different and vaccination does not guarantee they won't get the disease at some point in time also.

Lastly, these types of articles fuel the "unvaccinated should not be allowed in public school" because they are a health risk to the herd mentality - but when you understand all the above you can see how anyone can be a risk to the community at large.

It also leads to parents wanting the unvaccinated children personally identified, as another Mama said to me - with what a scarlet letter? And what road would that lead down - should people with other forms of communicable diseases (HIV, Hepatitis, etc) be labeled so we know they are a risk to us?

[MooMom]

Reason of CONSCIENCE not conscious

Medically CONTRAINDICATED not contradicted

Unvaccinated children are clearly statistically more likely to contract and pass on a vaccine preventable disease than vaccinated children. This has been demonstrated over and over again in the scientific literature. 100 vaccinated children will virtually always fare better than 100 unvaccinated children when confronted with the same disease exposure.

Fortunately, herd immunity will protect "Mother of an Child Who is No Longer Vaccinated's" child....that is until those pockets of unvaccinated children in the maps begin to affect herd immunity and put other children (the relatively small numbers of primary and secondary failures in particular) at risk and ends the herd immunity that the unvaccinated currently enjoy/take advantage of.

MooMom - part of the herd and proud of it

[Mother of an Child Who is No Longer Vaccinated]

Well in order to benefit from herd immunity you have to believe in it. Seeing I don't believe in herd immunity I am not enjoying or taking advantage of anything.

Certainly wasn't relying on the herd when we visited children living in squalors in Cuba, etc.

You could plop our family in any part of the world where vaccinate rates are much lower and it would not change our opinion. We don't fear disease.

We've been through exposure to chicken pox and pertusiss without getting them - the vaccinated children were the ones sick, not mine.

Glad you're proud to be a part of the herd.

I've always preferred to be an individual and not follow the herd. I am proud of that.

[MCB]

As a physician/scientist who treats children, I am very concerned about some parent's beliefs.

The concept of herd immunity has more to do with ability to limit/control epidemic outbreaks but nothing to do with the ability to eliminate spread of infrection because the infectious agents are always in the enviroment.

Of the many measles outbreaks in the US the majority affected are foreign visitors or foreign born citizens, who have not been vaccinated. It is difficult to argue herd immunity with the infectious agents still out there. I suspect we will begin to see a rise of infections in US born but unvaccinated children soon.

In response to the parent posting the refusal to vaccintate against pertussis, I saw 4 cases last year as did each of my immediate colleages. Multiply that times the number of persons who also take care of children and the numbers can be staggering. If the CDC pertussis incidence(or any other infection) seems low, it is because many cases go unreported.
Signed,
Concerned science advocate for children.

[Maryn McKenna]

Hi, just to let you know we have blogged these maps on Poynter.org, the US journalists' site.
http://www.poynter.org/column.asp?id=31&aid=144956
Nice!

Maryn McKenna
Poynter E-Media team

[DavidM]

Some of the private and alternative schools have few students so only 3 or 4 unvaccinated students put them, by percentage, in the highest category. Also, at least one school I'm familiar with was identified not by its location near the Beach, but by a mid-town address. Perhaps this was the address of the school’s owner?

[D.B]

Yes,I agree that, some parents don't want to be serious about the vaccinated. Sometimes, they show awful careless health support toward their kids. It's really sucks.They should be more careful about their children and make sure that their kid's get the vaccine. Atleast when school is giving a chance.