PANAMA CITY, Panama -- One in four children in Latin America and the Caribbean does not have vaccine protection against three potentially deadly diseases, a UN report said Monday, warning of plummeting inoculation rates.

While 90 percent of children in the region in 2015 had received the vaccine for diphtheria, tetanus and whooping cough (DTP3), by 2020 coverage had dropped to three-quarters, according to the UN Children's Fund (UNICEF) and the Pan American Health Organization (PAHO), a regional office of the WHO.

This means some 2.5 million children were not fully protected -- and 1.5 million of them have not had even one dose in the three-shot regimen.

Globally, according to the World Health Organization, 17.1 million infants did not receive an initial dose of DTP3 vaccine in 2020, and another 5.6 million were only partially jabbed.

Outbreaks of preventable diseases "have already occurred" in Latin America and the Caribbean, the agencies said.

In 2013, only five people in the region contracted diphtheria -- a bacterial disease that can cause breathing difficulties, heart failure and potentially death.

Five years later, the number was nearly 900.

- Worsened by Covid -
There has also been a rise in cases of measles -- another disease that can be prevented with inoculation -- from nearly 500 cases in 2013 to more than 23,000 in 2019, said the statement.

"The decline in vaccination rates in the region is alarming," said UNICEF regional director Jean Gough.

The reasons were multifold.

"The context in the region has changed in the last five years. Governments have focused their attention on other emerging public health issues such as Zika, chikungunya and more recently Covid-19," UNICEF neonatal expert Ralph Midy told AFP.

"The existence of migrant populations that are difficult to locate and do not always have access to regular health services, in addition to people living in isolated or hard-to-reach areas, also hinders the vaccination process."

The downward trend started even before the Covid-19 epidemic, which worsened the situation by interrupting primary health care services and causing some people to avoid clinics and hospitals for fear of the virus.

"As countries recover from the pandemic, immediate actions are needed to prevent (vaccine) coverage rates from further dropping, because the re-emergence of disease outbreaks poses a serious risk to all of society," said Gough.