A recent study conducted by researchers in China assessed the duration and extent of residual immunity to smallpox in individuals who received the vaccinia virus Tiantan strain (VTT) vaccination over 43 years ago. The study also aimed to determine whether this smallpox vaccine-induced immunity provides protection against mpox virus (MPXV) infection.
Mpox, also known as monkeypox, is a viral disease caused by MPXV. It shares similar symptoms with smallpox, including fever and rash. Although mpox is less virulent with a lower mortality rate compared to smallpox, it has become a public health emergency of international concern.
The study involved 294 participants aged between 19 and 63 years, divided into three groups based on their age and vaccination history. The first group consisted of individuals born after routine smallpox vaccination was discontinued in 1981. The second group included individuals vaccinated between 1970 and 1980, and the third group consisted of individuals aged 54-63 years.
The researchers assessed the vaccinia-specific level of residual humoral immunity, neutralizing antibody titers, and vaccinia-specific IgG levels in all participants. They also evaluated the cross-antibodies to MPXV antigens to determine the potential protection against MPXV infection.
The study findings revealed that humoral immunity from smallpox vaccination persists in the Chinese population over 43 years of age. However, the levels of vaccinia-specific neutralizing antibodies decline with age. This suggests that individuals with low or no VTT-specific antibodies are susceptible to MPXV infection and may benefit from vaccination.
The study also found that VTT-specific IgG antibodies were present in the majority of participants who received the smallpox vaccine before 1981. Furthermore, high levels of antibodies targeting specific MPXV antigens were observed, indicating potential protection against MPXV infection.
In conclusion, the study emphasizes the importance of smallpox vaccines in preventing mpox infection. It recommends prioritizing an anti-MPXV strategy, particularly for individuals under the age of 43 who are at a higher risk of mpox infections.
Source: Signal Transduction and Targeted Therapy (No URL provided)
