New News About Tuberculosis Vaccine

Tuberculosis subunit vaccine MVA85A is designed as parenteral booster to bacille Calmette Guérin conferring extra protection against TB
poor children in dev country

One of the oldest vaccines, first used medically in 1921, and one of the deadliest diseases, have made the news recently.

Despite widespread use of the bacille Calmette–Guérin (BCG) vaccine, tuberculosis (TB) remains a leading cause of mortality, from a single infectious agent (Mycobacterium tuberculosis or Mtb).

The BCG vaccine is only partially effective (51%) and vaccines in development keep racking up disappointments in clinical trials.

"The currently available BCG vaccine is not effective,” said McGill University's Maziar Divangahi, Ph.D. a pulmonary immunologist.

“The current antibiotic treatments are toxic and have resulted in generating TB-resistance strains. The antibiotics era is approaching its end; we are in serious trouble with this bug if we don't investigate an alternative approach," said Dr. Divangahi.

According to the World Health Organization, BCG is administered to 100 million children per year, globally.

With TB looking more dangerous than ever, as it evolves resistance to current antibiotics, vaccine developers are considering different approaches, such as:

  • A new tuberculosis subunit vaccine, MVA85A, pioneered by Oxford University has raised various concerns. MVA85A is designed as a parenteral booster to be given after BCG, hoped it would confer extra protection against TB compared with BCG alone. There are claims suggesting the preclinical vaccine tests were misrepresented by the research team. The university itself has said that three separate investigations into the research have cleared the academics behind it of any wrongdoing whatsoever.
  • In a new, small, pre-clinical study, led by researchers from McGill University, scientists have shown that when BCG is given access to bone marrow stem cells, it can generate trained monocytes/macrophages, thereby generating protective immunity against TB. In the bone marrow, BCG can induce the reprogramming of hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs). The authors of the Cell article said: “BCG-educated HSCs generate epigenetically modified macrophages that provide significantly better protection against virulent M. tuberculosis infection than naïve macrophages.”

The BCG vaccine is not generally recommended for use in the United States because of the low risk of infection with Mycobacterium tuberculosis, the variable effectiveness of the vaccine against adult pulmonary TB, and the vaccine’s potential interference with tuberculin skin test reactivity, says the Centers for Disease Control and Prevention (CDC).

The BCG vaccine should be considered only for very select persons who meet specific criteria and in consultation with a TB expert in the United States.

USA healthcare providers who are considering BCG vaccination for their patients are encouraged to discuss this intervention with the TB control program in their area.

The BCG vaccination should only be considered for children who have a negative TB test and who are continually exposed, and cannot be separated from adults who:

  • Are untreated or ineffectively treated for TB disease, and the child cannot be given long-term primary preventive treatment for TB infection; or
  • Have TB disease caused by strains resistant to isoniazid and rifampin.

BCG vaccination should not be given during pregnancy.

Even though no harmful effects of BCG vaccination on the fetus have been observed, further studies are needed to prove its safety, reports the CDC.

Between 2011 and 2014 the wholesale price was $0.16 to $1.11 USD a dose in the developing world.  In the United States, the BCG vaccine costs $100 to $200 USD.

The CDC Vaccine Price List provides the private sector prices for general information.

Vaccine discounts can be found here.

Vaccines, like any medicine, can have side effects, says the CDC. You are encouraged to report negative side effects of vaccines to the FDA or CDC.