[2] On the other hand, newer PTLVs are simply placed into the group by similarity and their connection to human disease remains unclear.

The only other recognized species in the genus is Bovine leukemia virus, an economically-important cattle pathogen.

A retrovirus, PTLV shares the common gag-pro-pol-env set of genes, yet shows great complexity in the unique 3' end.

Unusually, the single-stranded RNA genome is present in two copies, forming a dimer specifically packed by parts of the gag protein.

Discovered by Robert Gallo and colleagues in 1980,[14] HTLV-1 has been implicated in several kinds of diseases, including tropical spastic paraparesis and as a virus cancer link for adult T-cell leukemia/lymphoma.

It might impact the platelet count,[22] contribute to chronic lung infections,[23] or lead to future cutaneous T-cell lymphoma (CTCL),[24] among a host of other proposals.

Plasmid DNA vaccines elicit potent and protective immune responses in numerous small-animal models of infectious diseases.

In the past two decades a large initiative has been put forth to understand the biological and pathogenic properties of the human T-cell lymphotropic virus type 1 (HTLV-1); this has ultimately led to the development of various experimental vaccination and therapeutic strategies to combat HTLV-1 infection.

A vaccine candidate that can elicit or boost anti-gp46 neutralizing antibody response may have a potential for prevention and therapy against HTLV-1 infection.

Potential treatments include prosultiamine, a vitamin B-1 derivative, which has been shown to reduce viral load and symptoms;[37] azacytidine, an anti-metabolite, which has been credited with the cure of a patient in Greece;[38] tenofovir disoproxil (TDF), a reverse-transcriptase inhibitor used for HIV; cepharanthine, an alkaloid from Stephania cephalantha Hayata;[39] and phosphonated carbocyclic 2'-oxa-3'aza nucleosides (PCOANs).

[40] A newer formulation of TDF, called tenofovir alafenamide (TAF), also has promise as a treatment with less toxicity.