Table 1.

Major strategies have been used clinically or potential for the treatment of HCMV infections.

Strategy	Adoption	Current Status	Main Problem
Antiviral drugs	Traditional: ganciclovir, valganciclovir, cidofovir, foscarnet Novel: letermovir, maribavir	Extensively used clinically for the treatment of acute infections	Side effects, toxicity, resistance issues including drug resistance and cross resistance
Nucleic acid-based gene targeting approach	EGSs-RNase, CRISPRs/Cas9, TALENs	Only under study for basic research, not for clinical application so far	Option of delivery tool, safety concerns
Cell therapy	ACT, immunotherapy	Not universal, only used conditionally in limited patient population or special cases	Efficacy evaluation is difficult, Random controlled clinical trials and prognosis manifestation is still lacking

Abbreviation: External guide sequences (EGSs)-RNase; the clustered regularly interspaced short palindromic repeats (CRISPRs)/CRISPR-associated 9 (Cas9) nuclease system; transcription activator-like effectors nucleases (TALENs); adoptive T cell therapy (ACT).