Mariano Quisto, a remote community leader in Peru's dense Amazon rainforest, first learned of the global pandemic in October when health workers arrived by boat at his isolated village with vaccines.

"We didn't know about COVID-19. This is the first we are hearing about it," Quisto said through a translator from the village of Mangual, in Peru's vast but sparsely populated Loreto region in the country's north.

Reuters arrived with government health workers and International Red Cross members in Quisto's Urarina indigenous community, after a three-day boat ride along rivers starting from the Amazonian city of Iquitos, the world's largest metropolis that is unreachable by road.

In Mangual, the village highest up the river, residents hunt and fish for food and live in wooden stilt houses with no electricity. Connection with the outside world is minimal and the local language developed in isolation over centuries.

"Brigades haven't come here in many years. These communities are really forgotten," said Gilberto Inuma, president of Fepiurcha, an organization advocating for Urarina rights.

The broader Urarina indigenous group, one of Peru's most insular, has just 5,800 people, official data show. Not all communities have been spared from the knowledge, or impact, of the pandemic. At least five Urarina people have died of COVID-19, Inuma said.

The trip upriver underscores the challenges of vaccinating remote indigenous communities in Peru and beyond, as well as gaps in wider healthcare access for remote groups.

Many community members complained that what they really needed was better continuous healthcare services.

In the village with no doctors, ailments include headaches, diarrhea, malaria and conjunctivitis, Quisto said. "We don't know how to take care of our patients. That's our worry."

Indigenous communities, especially in the Amazon, have some of Peru's lowest vaccination rates, said Julio Mendigure, who heads health policy for the groups at the country's health ministry.

Less than 20% of them have been fully vaccinated, compared to around half for the country as a whole, he said.

"When you look at that number, you have to remember that to administer both doses, teams have to travel 4-5 hours. That's in the best case scenario," Mendigure explained. Reaching Mangual required 26 hours of travel over three days along rivers that at times dry up or are blocked with fallen trees.

The boat included a blue cooler box carrying 800 doses of China's Sinopharm vaccine, refrigerated with dry ice. A team will return in November to give second doses after administering over 600 inoculations.

"I decided to get the vaccine so that I don't get sick," said one Urarina woman who was inoculated and asked not to be named because the community so infrequently speaks to outsiders.

"Because it's possible if traders come to visit they will bring the disease and pass it on."