March 2026: The recent CDC announcement about polio has created much confusion. The bottom line is that it’s NOT coming back, it has NOT increased, and there is no more risk now than in the past 40 years. Traveling to any industrialized country is safe, and if you have previously decided to not vaccinate against polio the current disease status should not impact that choice. Read on to understand what the CDC statement really means and why I can confidently make the above statement.
First, understand that all countries that still use the live oral polio vaccine, like the ones on the CDC’s list in Africa, will always have the vaccine strains of polio show up in their wastewater systems. THAT is what creates these positive surveillance results – the actual VACCINE STRAINS coming out in the stools of vaccinated people in these countries, and routine testing of wastewater is actually how they insure that the people in that area are vaccinating adequately. Most developed countries, like the U.S., use the killed injected polio vaccine that doesn’t shed and can’t spread to others.
Second, cases of the real infection (known as wild-type polio) have actually decreased from 2024 (99 cases) to 2025 (41 cases). And these have all occurred in Pakistan and Afghanistan. Those are the only two countries where the real disease is actively occurring, and that hasn’t changed.
What is new is that vaccinated people who can shed the vaccine strains of the virus in their stools travel or move to countries in Europe and America, and those viruses show up in our wastewater (such as what was found in New York two years ago). That is why these European countries have made the list. There were also a few people who did bring the wild-type infection into some countries, like Spain and Germany. But the infection is not spreading. It is well contained.
So why the CDC’s warning? Great question, and I don’t know the answer. Almost all of the countries on the CDC’s list have always been at level 2. Level 1 is zero risk; level 4 is major outbreak. Level 2 is just to be aware that there is a very tiny risk of catching vaccine strains of the virus from the wastewater, so be careful. I don’t know who goes and plays in wastewater when on vacation, but I appreciate the CDC warning me not to. Some of the European countries on the list are new, so maybe that’s why the CDC put out this statement. OR, maybe they did this so that everyone would talk about it and realize that the only danger to travelers comes from the actual vaccine itself, not the wild-type disease. And this might make people think …
The truth is that yes, you can actually develop paralytic polio from exposure to these vaccine strains through wastewater. But the chance of this happening to travelers who follow common-sense precautions is as close to zero as you can get without actually being zero.
If you feel like you are going to be exposed to unavoidable unsanitary living conditions or unclean water sources in countries where vaccine-strains of polio are a concern (See CDC information here), you can and should discuss your options for vaccinating with your doctor. Getting two doses of the injected polio vaccine, two months apart, will give you vaccine-induced protection. Getting a third dose about 6 months after the second adds a bit more protection.