Vaccines for Rickettsia typhi
In the past century, great progress has been made in the development of vaccines for the prevention of rickettsial disease, but no new rickettsial vaccine has yet been produced. Early rickettsial vaccines were difficult, expensive and very hazardous to produce. Creative Biolabs is developing a standardized, inexpensive, harmless and effective rickettsial vaccine through molecular biology techniques and strives to meet all the needs of customers.
Rickettsia typhi
Rickettsia typhi (R. typhi), a gram-negative, obligate intracellular bacterium, is the causative agent of murine typhus (endemic typhus). Murine typhus is one of the most prevalent rickettsial infections in the world and transmitted by the rat flea, Xenopsylla cheopis, and brings about damage in infected areas. Infection with R. typhi causes fever, headache, and myalgia. If not treated in time, it will lead to disseminated multisystem diseases including infection of brain, lung, liver, kidney and heart endothelial cells, diffuse alveolar damage and hemorrhage, interstitial pneumonia, interstitial myocarditis, and nephritis, etc. In the acute phase of the disease, non-specificity and non-uniformity of symptoms and lack of specific diagnostic tests often lead to misdiagnosis and delay of appropriate treatment.
Vaccines for Rickettsia typhi
- Live Vaccines
- Subunit Vaccines
People use the closely related R. typhi to stimulate a strong and broad immune response that would protect individuals from both murine and epidemic typhus. One of the initial live typhus vaccines was living bile vaccine for epidemic typhus which used an R. typhi strain from Casablanca. In this typhus vaccine, infected adrenal glands, spleen and tunica vaginalis of a single male guinea-pig were dried and emulsified in saline where ox bile was added. Other living typhus vaccines are made by researchers from attenuated R. typhi isolated from the endemic region. Some of them are derived from guinea-pig or rat dried brain material emulsified in egg yolk and suspended in olive oil. These live vaccines can produce a certain degree of protection, but their use is limited due to their large side reactions.
Due to the drawbacks of living typhus vaccines, it has been proposed to use rickettsial subunit human typhus vaccines composed of soluble surface proteins and glycoprotein antigens. These soluble proteins had been demonstrated to be immunogenic and protective. The immunodominant and most prevalent surface protein of the R. typhi is known as the outer membrane protein B (OmpB) which is responsible for the presence of a regularly arrayed surface structure or S layer. It elicits strong cellular and humoral immune responses in laboratory animals and provides protection in mouse and guinea-pig model, making it a good candidate for a subunit vaccine. However, owing to the intracellular nature of the R. typhi, mass production and downstream purification of the proteins are difficult. In order to solve this problem, we partially digest OmpB, screen and expresse a single fragment or combination of fragments necessary for immunoprotection, which is recognized by the sera of most typhus patients and is expected to be a vaccine candidate.
Features
- Correct folding and methylation modification of antigens
- Easy to purify and mass produce
- Very low side reaction and toxicity
- Production of high antibodies with high protection
In order to meet the needs of customers, Creative Biolabs has built a team of experienced scientists with the best instruments and each step is specifically designed to provide the best service for any rickettsial vaccine. If you have any special needs in rickettsial disease vaccine or be interested in learning more about our services, please feel free to contact us for more details.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
