The United Nations has warned of an "alarming" decrease in the number of children receiving life-saving vaccines around the world.

The drop included vaccinations for preventable diseases such as diphtheria, tetanus and measles, the U.N. said in a statement. The U.N.'s World Health Organization and UNICEF blame the decrease on the change in routine health care caused by the coronavirus crisis.

A vaccine is a biological preparation that provides active immunity to an infectious disease. A vaccine usually contains a substance that is similar to the disease-causing illness. It tells the body's immune system to recognize the substance as a threat and destroy it.

"Vaccines are one of the most powerful tools in the history of public health, and more children are now being immunized than ever before," WHO chief Dr. Tedros Adhanom Ghebreyesus said in a statement.

"But the pandemic has put those gains at risk. The avoidable suffering and death caused by children missing out on routine immunizations could be far greater than COVID-19 itself."

The WHO and UNICEF said that even when vaccines are available, many children who need them are afraid to leave their homes because of the coronavirus. Others face difficulties traveling because of COVID-19 restrictions.

But even before the spread of the coronavirus, the agencies said child vaccinations were already falling. They said nearly 14 million children did not get vaccinated against measles and pertussis in 2019. Most of these children live in Africa. Economic difficulties also prevented children in Brazil, India, Indonesia, Mexico, Pakistan and the Philippines from getting the needed vaccine.

COVID-19 has made routine vaccinations a major "challenge," UNICEF Executive Director Henrietta Fore said. She said vaccination programs need to be restarted urgently "before children's lives are threatened by other diseases. We cannot trade one health crisis for another."

The WHO says that before the spread of the coronavirus, more than 116 million, or 86 percent, of all babies born had been vaccinated every year for the past 10 years.

More than 20 life-threatening diseases can now be prevented by immunization, the WHO reports. In addition, new vaccines for major killers like diarrhea, cervical cancer, cholera and meningitis are being introduced in several countries, the agency said.

I'm Susan Shand.

VOA News reported this story. Susan Shand adapted it for Learning English. Bryan Lynn was the editor.

________________________________________________________________

alarming – adj. something that is worrisome or dangerous

routine – adj. a common or usual activity

immunity – n. to be vaccinated against a disease

pandemic – n. a contagious disease that moves from one country to another

immunize – v. to vaccinate someone against a disease

challenge - n. something that is difficult to do