The headlines are not helpful. This one is from CBS News:

“Mutant Polio Virus Spreads in Nigeria
124 Children Afflicted This Year By Paralyzing Disease, Believed To Be Caused By Same Vaccine Used To Fight It

And other new sources print the same story with even more frightening headlines…

Reality check please.

Let’s talk about Polio. I’m old enough to remember when our moms kept us from going to public pools in August, for fear of polio. I personally know three friends from my grade-school who contracted the disease, and later met two physicians who contracted it while treating patients. In those pre vaccination days, there were 25,000 cases a year in the United States alone.

Then came the Salk Vaccine, and no more polio.

Here we need to go into medical stuff.

The Salk vaccine is a “killed” virus, so there is no way to get the disease from it. But you do need booster shots.

Then they developed the “live” polio vaccine.  It was a mixture of several polio viruses, including the one that most commonly causes paralysis. It was easy to give (on a sugar cube).The viruses however were not “dead” but “attenuated”, which means very weak, so that the person getting the vaccine got a mild case of the virus and made his own antibodies.

But once in a great while (one estimate is one in 2.4 million cases in the US), the virus mutates inside the child who gets the vaccine. But since the child is already making antibodies, he usually doesn’t get sick: but children and adults who lack immunity can become infected the virus, (which is called “VAPP” for vaccine acquired paralytic poliomyelitis)  which, like the “wild” virus is spread via the four “F’s” (Fingers/flies/fluid/feces) . Those most vulnerable are those in poor health, malnourished children, people with immune system problems, people with cancer, and pregnant women.

So in recent years, even though certain populations in the US don’t allow vaccinations, there actually has been more cases of polio  from the vaccine than from the “wild” virus.

Ergo, your kids now have to get polio shots, just like grandmom used to get 50 years ago.

Yet when one has to give vaccines in desperately poor countries, the ability to give a simple sugar cube with three drops of vaccine is a lot easier and cheaper than buying syringes and teaching personnel to give shots (in the “good old days” we reused and sterilized glass syringes, or we would fill the syringe with ten injections and just reuse it until no vaccine was left,  but with the risk of HIV it means buying one syringe per injection).

So is the risk worth it?

Let’s look at India.

From the World Health Organization:

Each year, 25 million babies are born in India and the important question is: how many of them will eventually develop VAPP? In 1999, there were 181 cases of VAPP among children under 5 years old. If a similar number of VAPP cases occurred each year, then the risk of VAPP would be 7 (181/25) per million, or 1 per 143 000 infants born.

But without the vaccine at all, the cases are many times that.

What usually keeps the number of VAPP (polio from the vaccine) from spreading is “herd immunity”, so although the rare child will secrete the virus, those around him are immune and don’t catch it.

But what happens when you give the vaccine to a population where a lot of kids didn’t get vaccinated, because they are poor and there was no good public health system, or because the local “religious” authorities read some of the anti vaccine hysteria in the press and told parents not to allow their children get vaccinated?

That’s what is happening in northern Nigeria.

When Nigerian leaders suspended polio vaccination in 2003, believing the vaccine would sterilize their children and infect them with HIV, Nigeria exported polio to nearly two dozen countries worldwide, making it as far away as Indonesia.

But now lack of “herd immunity” is allowing the VAPP virus to start it’s own epidemic, whereas in “normal” populations, it would only infect the immediate family. But when vaccinations are stopped, due to war, societal disruption, or paranoia, the herd immunity fails, and more cases of VAPP appear.

But again, let’s have some perspective here:

This year, the number of polio cases caused by the vaccine has doubled: 124 children have so far been paralyzed, compared to 62 in 2008, out of about 42 million children vaccinated. For every case of paralysis, there are hundreds of other children who don’t develop symptoms, but pass on the disease.

Now for the big news, which you probably never knew about.

Years ago, a huge effort was made to eliminate smallpox, and it was successful. Smallpox now exists only in a few biohazard labs, and unless some terrorist is dumb enough to release it, that killer is no more.

So the World Health Organization is aiming to do the same to polio.

The global eradication of poliomyelitis is a public health effort to eliminate all cases of poliomyelitis (polio) infection. The global effort, begun in 1988 and led by the World Health Organization, UNICEF and The Rotary Foundation, has reduced the number of annual diagnosed cases from the hundreds of thousands to around a thousand.

and it is working:

In 2006 only four countries in the world (Nigeria, India, Pakistan, and Afghanistan) were reported to have endemic poliomyelitis. Cases in other countries are attributed to importation. A total of 1,997 cases worldwide were reported in 2006; of these the majority (1,869 cases) occurred in countries with endemic polio.[19] Nigeria accounted for the majority of cases (1,122 cases) but India reported more than ten times more cases this year than in 2005 (676 cases, or 30% of worldwide cases). Pakistan and Afghanistan reported 40 and 31 cases respectively in 2006. Polio re-surfaced in Bangladesh after nearly six years of absence with 18 new cases reported. “Our country is not safe, as neighbours India and Pakistan are not polio free”, declared Health Minister ASM Matiur Rahman.[37]

And of course it doesn’t help that the Taliban killed the Pakistani physician trying to vaccinate children in their area of that country.

But the outbreak in Nigeria is worrisome to public health physicians, and one suspects that it might cause public health authorities to change to the safer but much more expensive shot to stop polio.

The problem, of course, is if the difficulty and expense of giving a shot versus handing out a simple sugar cube might result in a lot less polio vaccine being given to children, and a resurgence of the disease anyway.

In countries with limited public health budgets, the increased budget to eliminate polio has to be balanced not only against disease because of fewer immunizations being given, but that the money might better be spent to prevent other diseases, such as malaria, which kill many many more children and adults every year (Malaria killed 300 thousand people in Nigeria last year).

Finally, in today’s connected world, one has to realize that polio in Nigeria is a risk to all of us, because polio can be exported to other countries. Unless it is completely eliminated, the shots (or in poor countries) the oral vaccine with it’s tiny risk, will continue to be needed to protect children.

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Nancy Reyes is a retired physician living in the rural Philippines. Her website is Finest Kind Clinic and Fishmarket, and she writes medical essays at HeyDoc Xanga Blog.

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