Despite its storied past almost two decades ago, the rotavirus vaccine has contributed to massive preventative gains in the United States over the last several years, in both human and financial costs, a new study finds.

Before the age of 5, nearly every child in the world will, at some point, suffer a rotavirus infection. The consequences are great: severe diarrhea and persistent vomiting. But the introduction of a vaccine in the late 1990s, and then an updated and safer version roughly a decade later, have made the virus nearly wholly vulnerable. Today, the rotavirus still claims the lives of an estimated 450,000 children under five years old. Eighty-five percent of these children live in developing countries, where access to a vaccine is all but impossible.

The main reason children enter the hospital because of a rotavirus infection is diarrhea. The virus leaps between hosts via contaminate hands, surfaces, and objects — and in remarkably small concentrations, too. An infected person can contain more than 10 trillion infectious particles per gram, but fewer than 100 are needed to infect another person. Perhaps the only upside to a rotavirus infection is that immunity typically follows infection. As kids age, their likelihood of symptoms reduces. Adults are mostly immune.

The vaccine goes a tremendous way toward minimizing those infections, the latest study found. Between 2007 and 2011, over 175,000 U.S. children avoided hospitalization, more than 240,000 emergency department visits were saved, some 1.1 million outpatient visits were prevented, and nearly $1 billion in health care costs ($924 million) were saved as a result of the vaccine’s reductions, the team estimates.

The findings are particularly poignant because of the ongoing controversy regarding vaccine’s relationship with autism. Ostensibly, the results should serve as another nail in the coffin that while vaccinating young children with multiple batches of extremely low-grade viruses may seem harmful, in fact the opposite is true.

No data has found that autism is a product of normal vaccination schedules. A recent study found that between the ages of seven months and 10 years, children who received the standard immunizations suffered no neurological disorders as a result of their vaccinations in infancy. “Some parents are concerned that too many vaccines administered too early in life may adversely affect a child’s health, including neuropsychological development,” said the study’s lead author, Dr. Shahed Iqbal, from the Centers for Disease Control and Prevention. These concerns can lead to vaccine refusals or delays, which put not only that child at risk but each child he or she comes in contact with.

Certainly, rotavirus’ overwhelming success should hope to silence the vaccine’s opponents. As both vaccination and autism rates continue to rise — autism now affects one in every 68 children; 10 years ago it was one in 150 — critics’ voices are likely only to get louder. That is, unless the anti-vaccination movement tips in the group’s favor, and diseases begin to spike in prevalence. Maybe then will the consequence of vaccine refusal finally become clear.

Source: Leshem E, Moritz R, Curns A, et al. Rotavirus Vaccines and Health Care Utilization for Diarrhea in the United States (2007–2011). Pediatrics. 2014.