Why Relief Agencies Are Rushing Polio Vaccines to Gaza

In July, health officials made an unsettling discovery in Gaza: Poliovirus, a global scourge, was found in samples of wastewater. This month, the news got worse. A 10-month-old baby contracted polio and is now paralyzed in one leg.

It’s the first confirmed case of polio in Gaza in 25 years. Now international agencies are sending more than 1.6 million doses of oral poliovirus vaccine to the conflict zone in an ambitious effort to immunize 640,000 children under age 10.

Israel has agreed to three pauses in military operations, starting Sunday, to facilitate the campaign.

Health officials had been warning for months that the conflict in Gaza could eventually give way to major regressions in infectious diseases. Transmission of poliovirus — which attacks the nervous system and can lead to spinal and respiratory paralysis, and in some cases death — may already be widespread, some experts fear.

Here’s what you should know.

How could there be polio in Gaza?

Of the three naturally occurring “wild-type” viruses, only Type 1 remains; Type 2 and Type 3 have been eradicated.

But there is another form to worry about: so-called vaccine-derived poliovirus. This form now accounts for most outbreaks worldwide.