Know what improves the efficacy of TB vaccine
By Jahanbee Gupta
New York, Jan 2 (IANS) Researchers have shown that simply changing the dose and route of administration from intradermal (ID) to intravenous (IV) greatly increases the vaccine's ability to guard rhesus macaques against infection following exposure to tubercle bacillus (Mtb), the bacterium that causes TB.
Given to infants via a needle placed slightly below the skin, BCG protects babies from a sort of the disease called disseminated TB but is far less effective at preventing pulmonary TB. The findings from the University of Pittsburgh within the US, provide a replacement understanding of the mechanisms of BCG-elicited protection against tuberculosis infection and disease.
According to the researchers, to manage Mtb infection and stop clinical disease, a TB vaccine must elicit strong, sustained responses from the immune system's T cells, specifically those within the lungs. However, the quality, ID, route of BCG administration won't generate enough of those critical cells within the lungs.
The research team hypothesized that the administration of BCG by IV or aerosol (AE) routes would overcome this hurdle and thus confer substantially better protection from infection and disease in rhesus macaques following challenge with virulent Mtb.
All unvaccinated animals and people immunized via ID or AE routes showed signs of significantly greater infection. The investigators concluded that IV BCG conferred an unprecedented degree of protection in an animal model of severe TB and 'represents a big breakthrough within the world of TB vaccine research.'