Sometimes vaccines can eradicate widespread disease, like MMR, diphtheria, polio, smallpox. Sometimes they can mired in controversy, like the fight over whether they cause autism. In this case, it's the former.

A study published June 3 in JAMA discusses the first opportunity to assess the association between vaccination and rotavirus disease in a developing country. Rotavirus is a serious virus - it's the leading single cause of severe diarrhea among infants and young children. And unlike some diseases rampant in areas with poor sanitation, rotavirus is pretty much everywhere. In fact, you've almost assuredly been infected with it at least once in your life. Granted, only about 1 in 20,000 kids in the U.S. die before age 5 from the most common strain of rotavirus (A), versus places like Vietnam (1 in 61-113) or Bangladesh (1 in 390-660). Still, it's a difficult issue, and vaccines have only recently entered the U.S. market.

Bar = 100 nm. Electron micrograph, courtesy EPA.

A pentavalent rotavirus vaccine prevented 98% of severe rotavirus diarrhea in a trial conducted in the U.S. and Finland, but these are industrialized countries.

The case-control study's primary outcome was the association of RV5 and rotavirus diarrhea requiring overnight admission or intravenous hydration in the emergency department. Of the 285 rotavirus cases, 191 (67%) were severe and 54 (19%) were very severe. The same strain was present in 88% of the cases.

Effectiveness of 3 doses of RV5 against rotavirus disease requiring admission or treatment with intravenous hydration was 46%, the authors report. Against severe rotavirus diarrhea, 58%, and against very severe rotavirus diarrhea, 77%. Not quite up to the 98% mark, but still a significant improvement.

Now all we need is a Bill Gates or Warren Buffett to contribute enough money to get these drugs developed and distributed to people in need.