| Abbreviations | Meaning |
 | MDV | Marek Disease Virus |
 | MEAV | Meaban Virus |
 | MEGMV | Megakepasma Mosaic Virus |
 | MELV | Melao Virus |
 | MESV | Murine Embryonic Stem-cell Virus |
 | MEV | Maximum Exercise Ventilation; Mevalonate; Minimal Excursionary Ventilation; Murine Erythroblastosis Virus |
 | MEV | Measles Virus; Megaelectron Volts |
 | MHV | Magnetic Heart Vector; Middle Hepatic Vein; Mouse Hepatitis Virus; Murine Hepatitis Virus |
 | MICV | Micropia Virus |
 | MIDV | Middelburg Virus |
 | MINV | Minnal Virus |
 | MIRV | Mirim Virus |
 | MIV | Mosquito Iridescent Virus |
 | MLS | Mouse Leukemia Virus |
 | MLV | Moloney Leukemia Virus; Mono Lake Virus; Multilaminar Vesicle; Murine Leukemia Virus |
 | MLVAR | Amphotropic Receptor For Murine Leukemia Virus |
 | MMLV | Moloney Murine Leukemia Virus; Montana Myotis Leukoencephalitis Virus |
 | MMTV | Mouse Mammary Tumor Virus |
 | MMULV | Moloney Murine Leukemia Virus |
 | MNPV | Multiple Nucleopolyhedrovirus |
 | MNTBV | Manitoba Virus |
 | MNTV | Minatitlan Virus |
 | MO-MSV | Moloney Murine Sarcoma Virus |
 | MOBV | Methylhydroxy-benzovesamicol; Mobala Virus |
 | MOCV | Molluscum Contagiosum Virus |
 | MODV | Modoc Virus |
 | MOJUV | Moju Virus |
 | MOKV | Mokola Virus |
 | MOMLV, MO-MLV | Moloney Murine Leukemia Virus |
 | MOPV | Monovalent Oral Poliovirus Vaccine; Mopeia Virus |
 | MORV | Moriche Virus |
 | MOSV | Mossuril Virus |
 | MOV | Metal-oxide Varistor; Minimal Occlusive Volume; Molluscum-like Poxvirus |
 | MOV | Mottle Virus |
 | MPKV | Maprik Virus |
 | MPLV | Myeloproliferative Leukemia Virus |
 | MPMV, M-PMV | Mason-Pfizer Monkey Virus |
 | MPOV | M'Poko Virus |
 | MPRV | Mapuera Virus |
 | MPSV | Myeloproliferative Sarcoma Virus |
 | MPV | Micromonas Pusilla Virus |
 | MPXV | Monkeypox Virus |
 | MQOV | Mosqueiro Virus |
 | MRD | Measles-rindenpest-distemper [virus Group] |
 | MRV | Magnetic Resonance Venography; Mammalian Orthoreovirus; Minute Respiratory Volume; Mitchell River Virus; Mixed Respiratory Vaccine |
 | MRVI | Mixed Virus Respiratory Infection |
 | MSGV | Mouse Salivary Gland Virus |
 | MSPV | Malpais Spring Virus |
 | MSV | Master Seed Virus |
 | MSV | Moloney Sarcoma Virus |