Study finds TB vaccine less effective when administered as part of routine immunizations

A clinical study of the MVA85A TB vaccine found it to be less effective at stimulating an immune response when administered to infants in combination with the routine immunization schedule.

While MVA85A was deemed to be well tolerated, safe and able to induce a strong immune response, but the immune response was lower in infants who received it in conjunction with other vaccines for the Expanded Program on Immunization. The responses to the standard EPI vaccines were not affected by giving MVA85A at the same time.

The EPI schedule includes vaccines for diphtheria, tetanus and pertussis, in addition to Bacille Calmette-Guerin, the current vaccine for TB. MVA85A is given after BCG to boost the body's immune response and improve protection against TB.

"It's reassuring to see that MVA85A does not affect immunity to the other vaccines that are included in the EPI and important to see that it is safe in infants," Dr. Helen McShane, the developer of the MVA85A vaccine, said. "This study will help us determine the best way to integrate MVA85A into routine infant immunization schedules in future."  

The study, published in Science Translational Medicine, was led by Dr. Martin Ota at the Medical Research Council Unit in Gambia.

"These important results highlight that we have a real opportunity to make sure that children are protected in the future against tuberculosis by introducing effective and well-timed immunization programs," Dr. Ota said. "This can only be achieved with robust information gathered from well-conducted clinical trials such as this."