Mycobacterium microti ATCC 35782

Stage of Development

Preclinical Evaluation

Vaccine Platform

Mycobacterial – Live Attenuated

Candidate Overview

The Mycobacterium microti ATCC 35782 strain corresponds to the M. microti strain used in Prague in the 1960’s where it was known as the ‘M.P.’ strain, referring to the abbreviated form of ‘Murinus Praha’. The M.P. strain originates from Dr Wells’ OV166 strain, isolated from Orkney voles [3], which was then adapted by Dr Sula to fully synthetic medium and used for preparation of the different vaccine lots for human vaccination (see References under Additional Information).

Sponsor / Lead Developer: Institut Pasteur Paris

Primary Indication: Prevention of TB disease

Target Population(s): Elderly and People living with HIV

Target Route of Administration: Intradermal

Immune tissue localization: Lung and Lymph node

Immunological responses: T-cell

Preclinical Animal Models: Guinea pig and Mouse

Intended to elicit trained immunity: Yes

Additional Immunologic Response Information

Immune ResponseT-cell
T-cell phenotypeCD4
T-cell functional profileIFN-γ
Preferential immune tissue localizationLung
Lymph node
Trained immunityYes

Additional Information

We have recently tested this vaccine in a SCID mouse model and found that the Mycobacterium microti ATCC 35782 strain was completely inoffensive in this highly susceptible model (SCID mice still gained weight 21 weeks after infection while BCG-infected mice had all reached their humane endpoint by week 17). However, when tested for vaccine efficacy in a guinea pig model, the M. microti strain showed protection against a challenge with virulent M. tuberculosis that was similar to BCG-induced protection (Orgeur et al., Microbial Genomics 000505, DOI 10.1099/mgen.0.000505


Sula L, Radkovský I. Protective effects of M. microti vaccine against tuberculosis. J Hyg Epidemiol Microbiol Immunol 1976;20:1–6. Reference

Sula L, Zavadilova Z, Medulanova L, Pokorny J. [New vaccine against tuberculosis. II. Characteristics of the strain, Mycobacterium tuberculosis, murine type-Wells OV 166, and preparation of the vaccine]. Cas Lek Cesk 1952;91:161–171.