What is the HSV vaccine

HSV is a type of herpes virus. This virus can be transmitted through mutual contact, especially between people, which can easily lead to mutual transmission of these viruses, including oral herpes, herpetic dermatitis, and genital herpes. Therefore, in order to effectively reduce the infection of these viruses, HSV vaccination is naturally indispensable. Only by timely vaccination can the infection be blocked.

1. Introduction

Herpes simplex virus (HSV) belongs to the a-virus subfamily of the herpesviridae family, and the viral plasmid size is about 180 nanometers. In the STD hospital, the virus is currently divided into type 1 and type 2 based on antigenic differences. Type 1 is primarily acquired from oral lesions, and type 2 can be isolated from genital lesions. Infection is due to person-to-person contact. The number of people infected from four months to several years after the onset can reach 50-90% of the total population. It is the virus that is most susceptible to invading humans, but only a part of them will develop the disease clinically. This disease can be divided into: oral herpes, herpetic keratitis, herpetic dermatitis, genital herpes, Kaposi's disease, etc., and is sometimes also the cause of meningitis and encephalitis.

Pathogenicity

Patients and healthy people are the sources of infection, and the disease is mainly transmitted through direct close contact and sexual contact. HSV invades the body through multiple routes including the oral cavity, respiratory tract, genital tract mucosa and broken skin. Human infection is very common, with an infection rate of 80-90%. The common clinical manifestation is localized herpes on the mucous membranes or skin. Occasionally, severe systemic diseases may occur, involving the internal organs.

3. Primary infection

Infants under 6 months old mostly obtain antibodies from their mothers through the placenta. About 90% of the initial infection has no clinical symptoms and most infections are latent. Primary HSV-1 infection often occurs in children aged 1 to 15 years. The most common symptom is gingivostomatitis, which is a group of herpes that occurs on the buccal mucosa and gums. After rupturing, it is covered with a layer of necrotic tissue. In addition, it can cause cold sores, eczematous herpes, herpetic keratitis, herpetic encephalitis, etc. Genital herpes is more common after the age of 14 and is caused by HSV-2. It is relatively serious, with severe local pain, accompanied by fever, general malaise and lymphadenitis.

4. Latent infection and recurrence

After immunity is generated by primary HSV infection, most of the virus is cleared, and some of the virus can reach the cells of the trigeminal ganglion (HSV-1) and spinal ganglion (HSV-2) along the myelin sheath or in the surrounding astrocytes, where it persists in a latent state, in relative equilibrium with the body, and does not cause clinical symptoms. When the body has a fever, is exposed to cold, the sun, is menstruating, is under emotional stress, uses pituitary or adrenal cortex hormones, or is infected by certain bacteria or viruses, the latent virus is activated and proliferates, travels down the nerve fiber cords to the sensory nerve endings, and continues to proliferate in nearby epidermal cells, causing recurrent local herpes. Its characteristic is that each recurrence often occurs in the same location. The most common manifestation is the appearance of groups of small blisters at the junction of the skin and mucous membrane between the lips and nose. Herpetic keratitis, herpetic cervicitis, etc. may also recur.