Featured Research

from universities, journals, and other organizations

Harvard Team Creates Spray Drying Technique For TB Vaccine

Date:
February 23, 2007
Source:
Harvard University
Summary:
Bioengineers and public health researchers have developed a novel spray drying method for preserving and delivering the most common tuberculosis (TB) vaccine. The spray drying process could one day provide a better approach for vaccination against TB and help prevent the related spread of HIV/AIDS in the developing world.

Bioengineers and public health researchers have developed a novel spray drying method for preserving and delivering the most common tuberculosis (TB) vaccine. The low-cost and scaleable technique offers several potential advantages over conventional freezing procedures, such as greater stability at room temperature and use in needle-free delivery. The spray drying process could one day provide a better approach for vaccination against TB and help prevent the related spread of HIV/AIDS in the developing world.

The research team led by Yun-Ling Wong, a graduate researcher in bioengineering, and David Edwards, Gordon McKay Professor of the Practice of Biomedical Engineering, both at the Harvard School of Engineering and Applied Sciences, and Barry R. Bloom, Dean of the Harvard School of Public Health and Joan L. and Julius H. Jacobson Professor of Public Health, was sponsored in part by the Bill and Melinda Gates Foundation. The work appeared in the February 13 edition of the Proceedings of the National Academy of Sciences.

"With the increasing incidence of tuberculosis and drug resistant disease in developing countries due to HIV/AIDS, there is a need for vaccines that are more effective than the present Bacillus Calmette-Guιrin (BCG) vaccine," said Wong. "An optimal new vaccine would obviate needle injection, not require refrigerated storage, and provide a safe and more consistent degree of protection."

BCG, while the most widely administered childhood vaccine in the world, with 100 million infant administrations annually, is presently dried by freezing--or lyophilization --and delivered by needle injection. The commercial formulation requires refrigerated storage and has shown variable degrees of protection against tuberculosis in different parts of the world. Because of such limitations, public health experts and physicians have long seen a need for alternatives to the traditional BCG vaccine and current treatment strategies.

"The breakthrough for developing the spray drying process involved removing salts and cryoprotectants like glycerol from bacterial suspensions," explains Edwards. "This is counter to conventional thinking: that bacteria be dried in the presence of salts and cryoprotectants. While these substances are generally required for normal storage and freezing protocols, in the case of evaporative drying as occurs in spray drying, salt and cryoprotectants act like knives that press on the bacterial membrane with great force and inactivate the bacteria. By removing these, we managed to save the bacteria and achieve better stability."

The spray drying process developed for the BCG vaccine is similar to the way manufacturers prepare powdered milk. In fact, Edwards' first exposure to the spray drying process occurred when he was working with a spray dryer to produce highly respirable drug aerosols in a food science lab. While spray drying of small and large molecules is common in the food, cosmetic and pharmaceutical industries, the method has not been commonly used for drying cellular material. Most important, the new technique enables the BCG vaccine, and potentially other bacterial and viral based vaccines, to be dried without the traditional problems associated with standard freezing.

"Unlike traditional freezing techniques, spray drying is lower cost, easily scaleable for manufacturing, and ideal for use in aerosol (needle free) formulations, such as inhalation," says Wong. "Its greater stability at room temperature and viability ultimately could provide a more practical approach for creating and delivering a vaccine throughout the world."

Edwards, an international leader in aerosol drug and vaccine delivery, sees great promise for the advance, which he and his colleagues hope to develop in the next few years for better vaccination approaches for diseases of poverty through the international not-for-profit Medicine in Need (Mend), based in Cambridge, Paris, and Cape Town, South Africa.

"With the emergence of multidrug and extremely drug resistant TB, we hope this breakthrough is one more step to help us develop a stable vaccine to stem the tide of disease," says Bloom. "Better vaccination against TB can go a long way to addressing the current developing world health care crisis, with TB alone presently taking the lives of more than 2 million people a year. And we believe this method could also be used to improve delivery of many other vaccines."

Wong, Edwards, and Bloom's co-authors included Samantha Sampson and Sunali Goonesekera (Harvard School of Public Health); Willem Andreas Germishuizen (Harvard School of Engineering and Applied Sciences); Giovanni Caponetti (Eratech), Jerry Sadoff (Aeras Global TB Vaccine Foundation). The work was supported by a Grand Challenge Grant from the Bill and Melinda Gates Foundation and with a grant from the National Institutes of Health.


Story Source:

The above story is based on materials provided by Harvard University. Note: Materials may be edited for content and length.


Cite This Page:

Harvard University. "Harvard Team Creates Spray Drying Technique For TB Vaccine." ScienceDaily. ScienceDaily, 23 February 2007. <www.sciencedaily.com/releases/2007/02/070212184123.htm>.
Harvard University. (2007, February 23). Harvard Team Creates Spray Drying Technique For TB Vaccine. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2007/02/070212184123.htm
Harvard University. "Harvard Team Creates Spray Drying Technique For TB Vaccine." ScienceDaily. www.sciencedaily.com/releases/2007/02/070212184123.htm (accessed October 1, 2014).

Share This



More Health & Medicine News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) — A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) — A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com
Insertable Cardiac Monitor

Insertable Cardiac Monitor

Ivanhoe (Oct. 1, 2014) — A heart monitor the size of a paperclip that can save your life. The “Reveal Linq” allows a doctor to monitor patients with A-Fib on a continuous basis for up to 3 years! Video provided by Ivanhoe
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins