I. Contagiousness

I. Contagiousness

Hepatitis B is not highly contagious. In China, approximately 70% of the population has been infected with hepatitis B, yet only about 10% of those infected actually develop the disease. This means that 90% of infected individuals can easily eliminate the hepatitis B virus (HBV) that enters their bodies through their own immune mechanisms. Starting in the 1980s, China began implementing universal vaccination against hepatitis B. Three doses of the hepatitis B vaccine—administered one month and six months after the first injection—can transform the 10% of susceptible individuals into those who are no longer susceptible, thus depriving the hepatitis B virus of its opportunity to thrive. Having worked in hepatitis B clinical practice and research for over 30 years, I deeply feel that in recent years, the prevalence of hepatitis B in China has changed dramatically compared to the past. In outpatient clinics, the majority of cases were diagnosed in individuals who developed hepatitis B in the 20th century. Of course, the population born in the 21st century is not entirely free from hepatitis B; this is mainly due to blind spots and gaps in hepatitis B vaccination coverage, particularly in rural areas and mountainous regions, as well as the large numbers of migrant workers. Additionally, some parents were hepatitis B patients themselves, and their infants were not subjected to appropriate prenatal or postnatal care, allowing vertical transmission to occur. In conclusion, theoretically speaking, the contagiousness of hepatitis B can be completely contained by humanity. Today, this issue has been fully resolved in advanced countries; some nations no longer consider hepatitis B a contagious disease, and patients with chronic hepatitis B who test negative for HBV-DNA should not be admitted to infectious disease wards.