In descending order of activity:
Herpes simplex virus type I (HSV-1)
Herpes simplex virus type II (HSV-2)
Varicella zoster virus (VZV)
Epstein–Barr virus (EBV)
Cytomegalovirus (CMV)The drug is predominantly active against HSV and, to a lesser extent, VZV. It is only of limited efficacy against EBV and CMV. However, valaciclovir has been shown to lower or eliminate the presence of the Epstein–Barr virus in subjects afflicted with acute mononucleosis, leading to a significant decrease in the severity of symptoms. Valaciclovir and acyclovir act by inhibiting viral DNA replication, but as of 2016 there was little evidence that they are effective against Epstein–Barr virus, they are expensive, they risk causing resistance to antiviral agents, and (in 1% to 10% of cases) can cause unpleasant side effects. Acyclovir therapy does prevent viral latency, but has not proven effective at eradicating latent viruses in nerve ganglia.As of 2005, resistance to valaciclovir has not been significant. Mechanisms of resistance in HSV include deficient viral thymidine kinase and mutations to viral thymidine kinase and/or DNA polymerase that alter substrate sensitivity.It also is used for herpes B virus postexposure prophylaxis. Chemistry
Details of the synthesis of valaciclovir were first published by scientists from the Wellcome Foundation. Aciclovir was esterified with a carboxybenzyl protected valine, using dicyclohexylcarbodiimide as the dehydrating agent. In the final step, the protecting group was removed by hydrogenation using a palladium on alumina catalyst. History
Valaciclovir was patented in 1987 and came into medical use in 1995. It is available as a generic medication.
(1962)
Hannah and Her Sisters (1986)
Hanging Up (2000)
Frozen (2013)
Little Women (2019)

Literature
Little Women
Laura Lee Hopes Bobbsey Twins novels, which included two sets of fraternal twins: 12-year-old Nan and Bert, and six-year-old Flossie and Freddie
In Her Shoes (2002), novel
#Toots (2019), novel

Television
Hope & Faith, American sitcom
Sisters (TV series)
What I Like About You, TV series
Sister, Sister, TV series

Games
Jessica & Zofia Blazkowicz , Wolfenstein: Youngblood
Mileena & Kitana, Mortal Kombat
Kat and Ana, WarioWare

See also
Brother
Sisterhood (disambiguation)
Religious sister

References
External links
 The dictionary definition of sister at Wiktionary