Like all filoviruses, marburgvirions are filamentous particles that may appear in the shape of a shepherd's crook or in the shape of a "U" or a "6",
Who'd o thunk.
Biological weapon
The Soviet Union had an extensive offensive and defensive biological weapons program that included MARV.[57] At least three Soviet research institutes had MARV research programs during the Cold War: the Virology Center of the Scientific-Research Institute for Microbiology in Zagorsk (today Sergiev Posad), the Scientific-Production Association "Vektor" (today the State Research Center of Virology and Biotechnology "Vektor") in Koltsovo, and the Irkutsk Scientific-Research Anti-Plague Institute of Siberia and the Far East in Irkutsk. As most performed research was highly classified, it remains unclear how successful the MARV program was. However, Soviet defector Ken Alibek claimed that a weapon filled with MARV was tested at the Stepnogorsk Scientific Experimental and Production Base in Stepnogorsk, Kazakh Soviet Socialist Republic (today Kazakhstan),[57] suggesting that the development of a MARV biological weapon had reached advanced stages. Independent confirmation for this claim is lacking. At least one laboratory accident with MARV, resulting in the death of Koltsovo researcher Nikolai Ustinov, occurred during the Cold War in the Soviet Union and was first described in detail by Alibek.[57]
MARV is a select agent under US law.[58]