VOA常速英语:Rotavirus Vaccine Is Safe, Study Finds

Rotavirus is the most common cause of severe diarrhea in babies worldwide. The pathogen kills more than 500,000 children each year, according to data from the U.S. Centers for Disease Control. A vaccine against rotavirus was in wide use until it was pulled from the market a few years ago because of safety concerns. A study in the Journal of the American Medical Association examines the safety and effectiveness of another rotavirus vaccine now being used.

Nearly every child in the world gets infected with rotavirus by age three. The diarrhea it causes can result in severe dehydration and death.  More than 85 percent of the deaths from this virus occur in Asian and African countries. As many as 2 million children are hospitalized each year because of rotavirus infections.

The younger a child is, the more life-threatening the infection can be, which is why an oral vaccine is given to babies.

Babies normally get two or three doses starting when they are two months old. Several years ago, a rotavirus vaccine was taken off the market because it increased a baby's risk of developing a rare, but potentially deadly, intestinal blockage.

Other vaccines have since taken its place. But a manufacturer's study of one of them, the RotaTeq vaccine, suggested it, too, might cause intestinal blockage after the first dose. Epidemiologist Irene Shui, at the Harvard School Of Public Health, decided to investigate.

“Because the rotavirus vaccine is given to almost every child in the United States, it’s crucial to monitor the vaccine’s safety,” said Shui.

Shui and other researchers examined the records of almost 800,000 babies who received this vaccine, including 300,000 first doses. They were looking for incidents of intussusception, the medical term for this kind of blockage.

“We did not find an elevated risk of intussusception following any dose of the vaccine, and especially following the first dose,” she said.

Shui said even though the intestinal blockage is rare, it is important to continue to monitor these vaccines with additional studies like hers.

And she noted that the World Health Organization recommends the vaccine be included in all infant immunization programs.

“The benefits from rotavirus vaccine in terms of reducing the number of hospitalizations and deaths from rotavirus disease far outweigh the potential risk of intussusception that might exist.”

In the U.S., according to the Centers for Disease Control, the vaccines are up to 98 percent effective in preventing severe rotavirus disease in infants and young children.