"That is why it is more important than ever to do our part to protect and sustain polio elimination in our region while we wait for countries in other parts of the world to achieve this goal," Etienne added.

The pandemic has stressed immunization and surveillance systems designed to catch and respond to vaccine-preventable diseases, according to PAHO.

"Now during the pandemic, we must work extra hard to not lose what we have gained," said Cuauhtemoc Ruiz Matus, head of PAHO's Immunization Program.

Ruiz said that strong political commitment from governments, strategic partnerships between international agencies, and the work of health care workers contributed to the success to the region's fight against the virus.

"Without all of these things, we wouldn't be where we are today," said Ruiz.

Reported coverage for the polio vaccine for the Americas between 2016 and 2019 ranged between 85-87%, according to PAHO.

Coverage in 2020 might be lower "due to disruptions in primary health care activities caused by the COVID-19 pandemic," according to PAHO.

Polio once was a common virus.

In some young children it can affect the nerves and cause muscle weakness or paralysis.

There is no treatment and no cure but getting vaccinated can prevent infection.