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Updated: Jul 22, 2026

Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 1
Published on: April 8, 2009
Tissue distribution of the Ankara strain of vaccinia virus (MVA) after mucosal or systemic administration
J C Ramirez1, D Finke, M Esteban
1Centro Nacional de Biotecnología, CSIC, Campus Universidad Autonoma de Madrid, Spain.
Abstract:
MVA is a candidate vector for vaccination against pathogens and tumors. Little is known about its behaviour in mucosal tissues. We have investigated the fate and biosafety of MVA, when inoculated by different routes in C57BL/6 mice. Intranasal inoculation targeted the virus to the nasal associated lymphoid tissue and the lungs, whereas systemic inoculation led to distribution of MVA in almost all lymphoid organs, lungs and ovaries. Intravaginal, intrarectal and intragastric inoculations failed to induce efficient infection. After 48 h no virus was detectable any more in the organs analyzed. Upon intranasal inoculation, no inflammatory reactions were detected in the central nervous system as well as the upper and lower airways. These results show the tropism of MVA and indicate that high doses of recombinant MVA are safe when nasally administered, a vaccination route known to elicit strong cellular and humoral immune responses in the female genital tract.
Insights
Intranasal administration of modified vaccinia Ankara (MVA) is safe and targets mucosal tissues. This vaccination route shows potential for eliciting immune responses without causing inflammation, even at high doses.
Area of Science:
- Virology
- Immunology
- Vaccinology
Background:
- Modified vaccinia Ankara (MVA) is a promising vaccine vector for pathogens and tumors.
- Understanding MVA's behavior in mucosal tissues is crucial for effective vaccine development.
Purpose of the Study:
- To investigate the biodistribution, safety, and tropism of MVA following administration via different routes in C57BL/6 mice.
- To assess the potential of intranasal MVA delivery for inducing mucosal immunity.
Main Methods:
- Mice were inoculated with MVA via various routes (intranasal, intravaginal, intrarectal, intragastric, systemic).
- Viral fate and distribution were analyzed in lymphoid organs and other tissues up to 48 hours post-inoculation.
- Inflammatory responses in the central nervous system and airways were evaluated after intranasal MVA administration.
Main Results:
- Intranasal MVA inoculation localized the virus to the nasal-associated lymphoid tissue and lungs.
- Systemic inoculation resulted in widespread MVA distribution across lymphoid organs, lungs, and ovaries.
- Intravaginal, intrarectal, and intragastric routes did not support efficient MVA infection.
- No infectious MVA was detected in analyzed organs after 48 hours.
- Intranasal MVA administration did not induce inflammatory reactions in the central nervous system or airways.
Conclusions:
- MVA exhibits specific tropism depending on the inoculation route.
- High-dose intranasal administration of MVA is safe and well-tolerated.
- Intranasal MVA delivery is a viable strategy for inducing mucosal and systemic immune responses, particularly relevant for the female genital tract.
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