Emerging vaccines & Latent TB

Human Immunodeficiency Virus (HIV)

In the past 20 years since the development of the first antiretroviral medication, science has made great progress in combating the human immunodeficiency virus, or HIV.  Research on vaccines has not been promising as of yet, but starting this month, a new vaccine made from killed virus will begin its phase 1 trials.  Stay up to date with the Vaccine Trials Network: www.hvtn.org

Malaria

Plasmodium falciparum, the parasitic cause of severe malaria, relies on the anopheles mosquito and the human for its lifecycle.  Eradication of this disease is potentially feasible, if this cycle can be broken.  Interim results for a vaccine showed a 55% protection in infants given the vaccine.  Hope seems to be on the horizon, despite major setbacks in the development of multi-drug resistant strains.

Ebola

This hemorrhagic virus kills 90% of patients it infects.  Currently the only treatment available is supportive care.  Great strides were made in creation of a vaccine when a recent trial showed disease prevention in 80% of mice vaccinated.  The vaccine was created through genetically engineering bacteria to grow the viral surface proteins.

New Treatment Option for Latent Tuberculosis 

In 2010, nine million people around the world were diagnosed with tuberculosis, TB.  Over 11,000 cases were reported in the United States, where prevalence among Native Americans and Pacific Islanders was three times that of caucasian Americans.

Previous options for the treatment of latent TB consisted of either six to nine months of isoniazid or four months of rifampin therapy.  Long treatment durations are difficult for patients to adhere to until completion.

A multicenter randomized trial compared three months of rifapentine with isoniazid to nine months of isoniazid treatment for latent TB.  A total of 7731 patients were followed for 30 months.   

Combination therapy was found to be non-inferior with a trend toward superiority.  Patients taking combination therapy were significantly more likely to finish the treatment regimen, though were more likely to discontinue therapy due to an adverse event.  However, there was significantly less hepatotoxicity with combination therapy.

References:

HIV. CBC News: HIV vaccine trial approved by FDA: Canadian-developed vaccine to start human clinical trials in January 2012.  CBC News 12/20/11.  Available at http://www.cbc.ca/news/health/story/2011/12/20/hiv-vaccine-western.html 

Johnston MI.  HIV vaccine development- improving on natural immunity. The New England Journal of Medicine 2011;365(10):873-875. 

Malaria.    Schweitzer A, Todagbe S, Lell B, Soulanoudjingar SS,  Fernandes J, Abossolo BP, et al. Results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children.  The New England Journal of Medicine 2011;365(20):1863-75. 

White NM. A vaccine for malaria.  The New England Journal of Medicine 2011;365:1926-1927.  

Ebola. Carpenter J. Vaccine developed against ebola.  BBC 12/6/11. Available at http://www.bbc.co.uk/news/science-environment-16011748

New treatment option for latent tuberculosis. Morbidity and Mortality Weekly Report (MMWR). Decrease in reported tuberculosis cases --- United States, 2009.  Centers for Disease Control and Prevention 2010;59(10):289-294.  

Sterling TR, Villarino ME, Borisov AS, Shang N, Gordin F, Bilven-Sizemore E et al.  Three months of rifapentine and isoniazid for latent tuberculosis infection.  The New England Journal of Medicine 2011; 365(23):2155-66.