Scientists said they could not find any link between the measles-mumps-rubella vaccine and autism. As a response to a 1998 report that found that the measles vaccine caused gastrointestinal problems and that those problems led to autism, the researchers replicated key parts of the original study led by British physician Andrew Wakefield to determine if the vaccine causes autism. They found no connection between the vaccine and autism.

According to Wakefield’s theory, the virus used in the vaccine grows in the intestinal tract, leading to an inflammatory cascade that ultimately results in neurological damage and gastrointestinal disturbances.

The new study conducted by Dr. W. Ian Lipkin of Columbia University, collaborating with a team of the Centers for Disease Control and Prevention, Massachusetts General Hospital and Trinity College in Dublin involved 25 children with autism but without intestinal problems and 13 children who reported gastrointestinal problems but without autism. Scientists searched for genetic material linked to the virus in intestinal tissue taken from the first group of children and compared them to samples taken from the second group diagnosed with intestinal problems, but without autism. The samples were analyzed in three laboratories that were not told which came from the children with autism.

At the end of the study, researchers said they found no difference in children who had GI complaints and no autism and children who had autism but no GI complaints. There were no links found between the timing of the vaccine, which typically is first given when children are 12- to 15- months old, and the onset of autism, or vaccination and the bowel ailments.

“We find no evidence to support a link between a measles vaccine, intestinal difficulties and autism,” said Dr. Mady Hornig, associate professor of epidemiology and director of Translational Research, at Columbia’s Mailman School of Public Health Center for Infection and Immunity.

The study is published in the online journal of the Public Library of Science, PLoS ONE.

On the other hand, the Autism Society of America cautioned that the cause of autism was complex and more research was needed to fully understand the role of the vaccine. The society released a statement saying that the study “fell far short of what the public needs to prove the safety of the MMR vaccine.” The analysis is the latest of more than 20 studies that have dismissed a link between the vaccine and autism.

According to the Centers for Disease Control and Prevention, measles is a highly infectious disease that causes symptoms like rash, high fever, cough, runny nose and red, watery eyes. In rare cases, patients face more serious complications, including pneumonia, encephalitis and even seizure and death.

Many parents refuse to vaccinate their children because they think the shots may cause autism or other health problems. Unvaccinated persons are at risk of acquiring measles themselves and also transmitting the disease to others, including children who are too young to be vaccinated.

From January through July, 131 cases of the infectious disease were reported, the highest since 1996, the CDC said. Four outbreaks are ongoing in Arizona, New York, Michigan and Wisconsin. Autism and related disorders affect 1 in 150 U.S. children, according to the CDC.