Herpesviruses屬於很常見的一種病毒，目前已發現的約有一百種，存在於許多不同的生物體中。全部種類均屬於Herpesviridae。Herpes virus雖然種類繁多，但他們基本形式是相似的，例如他們感染宿主的機制。目前所知道的Herpes virus可分為三類，alpha, beta and gamma herpesviruses，如下表：
| Alpha herpesviruses | Beta herpesviruses | Gamma herpesviruses |
| Herpes simplex virus type 1 (HSV-1)
|
Cytomegalovirus (CMV) | Epstein-Barr virus (EBV) |
| Herpes simplex virus type 2 (HSV-2) | Human herpesvirus type 6 (HHV-6) | Human herpesvirus type 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus) |
| Varicella zoster virus (VZV) | Human herpesvirus type 7 (HHV-7) |
由於Herpes virus種類如此繁多，故研發它們共同的抑制劑相信可以有巨大的市場。所以Boehringer Ingelheim才會下手去研發它的抑制劑。
↑Herpes Simplex Virus
- Epstein-Barr virus, which causes infectious mononucleosis (also known as ‘mono’ and ‘glandular fever’);
↑Adolescent girl with infectious mononucleosis.
- Varicella zoster, which causes chickenpox and shingles;
 |
 |
 |
 |
|
↑Typical rash of chickenpox in
an adult.
|
↑Typical rash of chickenpox in
an adolescent.
|
↑Typical rash of chickenpox in
an adult.
|
↑Typical herpes zoster rash.
|
- Herpes simplex virus type 1, the cause of cold sores;
↑Typical blisters associated with cold sores due to HSV.
- Herpes simplex virus type 2, the most common cause of genital herpes.
