At its top secret medical facility, the U.S. military developed a safe and effective vaccine against the debilitating chikungunya [CHIK] virus, which infected 186,000 people, or 20 percent of Réunion’s population, 15,000 km (9,350 miles) away fromFort Detrick, Maryland. After several successful trials, the vaccine against this “potential bioterrorist agent” is stuck somewhere in the U.S. for military personnel only and has yet to see the light of day.
The military’s active interest in this disease dates back to the early 1960s when Thailand was overrun by simultaneous outbreaks of cholera, dengue and chikungunya. It is rarely lethal but has the potential to disable civilians and soldiers for weeks if not months.
Since World War II, the U.S. military scientists have been scouting the world for infectious diseases, studying them, investigating their potential for offensive biological weapons, finding cures, and planting research centers around the globe. It was epidemic cholera in Thailand that paved the way for the U.S. military to study the chikungunya virus and eventually create a live attenuated vaccine.
In the late 1950s and early 1960s, Thailand became ground zero for many prominent U.S. researchers who studied highly pathogenic, hemorrhagic forms of dengue fever, cholera and chikungunya. Dr. William McD. Hammon, Dr. Scott B. Halstead, Dr. E.J. “Gene” Gangarosa and others all ended up in Bangkok. Today the Walter Reed Army Institute of Research [WRAIR] still maintains a facility in the country.
In 1958, the U.S Naval Medical Research Unit II [NAMRU-2] based in Taipei was deployed to Bangkok, where a cholera epidemic offered them another chance to study it and refine treatment techniques explored by NAMRU-3 during the 1947 epidemic in Egypt. The team invented the “Watten cholera cot,” an Army cot that has a hole with a funnel under the rectum to collect choleraic stools. (It is gross to picture this cot, but it helped them get an accurate measurement of the stool in liters.)
In 1959, researchers from the U.S. National Institutes of Health and Walter Reed arrived to the study the cholera patients. Dr. Halstead arrived in 1961 just as dengue started sweeping Bangkok again and chikungunya turned out to be in the mix of the sometimes deadly coinfection of the two nasty bugs.
In 1962 alone, 357,000 people were infected with Dengue, Chikungunya or both, Dr. Halstead wrote in 1969 in the American Journal of Tropical Medicine and Hygiene. Chikungunya [CHIK] strain 15561 came from this outbreak and ended up in the United States, where it was used to manufacture a weakened version of the virus for use as vaccine.
“This promising live vaccine was safe, produced well-tolerated side effects, and was highly immunogenic,” wrote Dr. Robert Edelman in the American Journal of Tropical Medicine and Hygiene in 2000. In the Phase II safety and immunogenicity study by Dr. Edelman and others, 98 percent of vaccine recipients developed chikungunya antibodies by day 28, and 85 percent of the recipients remained seropositive after a year. Only a few volunteers experienced transient arthralgia. This vaccine was labeled “TSI-GSD-218.”
The U.S. Army Medical Institute for Infectious Diseases [USAMRIID] at Fort Detrick in Frederick, Maryland, conducted several Phase I trials, but efforts to find a cure began much earlier. Published studies about CHIK vaccine experiments began appearing in 1967 (Harrison, Am. J. Trop. Med. Hyg.), and in 1969 AMRIID, which had just been created out of the Army Medical Unit, submitted an experimental vaccine using the killed chikungunya virus. Walter Reed also tested a version of the vaccine in 1969.
The U.S. military considers chikungunya a threat to its forces and lists it as a “potential bioterrorist agent.” The vaccine was designed for soldiers deploying to CENTCOM, PACOM, SOCOM and EUCOM, according to the Federation of American Scientists, but it is unknown whether current soldiers are being given the vaccine. The U.S. Army Center for Health Promotion and Preventive Medicine tells American soldiers that there is no cure for the disease in a bulletin updated last month and recommends mosquito repellent.
Chikungunya is believed to have been documented as early as in 1779 Batavia, now Jakarta, Indonesia. The virus was isolated for the first time during the 1952-1953 outbreak in southern Tanganyika, now Tanzania. The name means “stooped walk” or “one that bends/folds up” in Swahili/Makonde and describes a key symptom of the disease — arthralgia, excruciating joint and muscle pain that can last weeks or months into convalescence.
Symptoms are generally similar to dengue fever which makes diagnosing a pain and could lead to misclassification. CHIK is mosquito-borne and sustained by human-to-mosquito-to-human transmission, making vector control, short of a vaccine, the most critical component of fighting the disease. In the latest outbreak, the vicious Asian tiger mosquito (Aedes albopictus), not the usual Aedes aegypti and others, is believed to be the primary vector, according to journal Science. (Vol. 311. no. 5764, p. 1085, 24 Feb. 2006)
According to the journal, the U.S. military blames funding shortage for the limbo in turning the vaccine loose for public use. In the meantime, chikungunya, which arrived in Le Réunion from the Comoro Islands in March 2005, has now spread to Mauritius where 2,553 cases have been reported. The number of reported cases in Mayotte was 924 and in the Seychelles 4,650.
Worse, in Réunion, 93 people died directly or indirectly from chikungunya infection.