Needle And Pain Free Vaccinations
The development of a needle - free vaccination delivery system has been identified by the Grand Challenges in Global Health ( GCGH ) initiative as one of the major challenges dissimilar global health care today.
Millions of needles and syringes are used each day in health care. The World Health Organization ( WHO ) estimates that 12 billion injections are inured each year. Only about 5 % are used in the delivery of vaccines for immunization and prevention of infectious diseases. Even though vaccinations have saved lives over the years, there are some hurdles to overcome. One of these is the use of needles or " sharps " to deliver the vaccines.
According to Myron Levine of the Center for Vaccine Development, University of Maryland School of Medicine and member of the Global Alliance for Vaccines and Immunization ( GAVI ) " three fundamental themes remain in common worldwide: first, high immunization coverage of target populations ofttimes must be attained for highest public health impact; second, most current vaccines are administered parenterally using a needle and syringe; third, there is a broad recognition of the need to find ways to direct vaccines without the use of ' sharps ' ( that is, needles and syringes ). "
The disadvantages of needle delivery of vaccine add:
( 1 ) Pain and irritation of vaccination site. A great sector of our population is scared of needles, average as consequence of a previous bad experience. The majority of patients at the delivery end of vaccination are very puerile children below the age of two and needle pricks in this patient population can generate a lot of pain and distress. Needles may also engender discomfort at the injection site long after the shot has been serviceable.
( 2 ) Want of compliance. The World Health Organization ' s Expanded Programme on Immunization ( EPI ) has recommended six basic vaccines for infants in developing countries: diphtheria, pertussis, and tetanus toxoids ( DPT ), bacillus Calmette - Guerin ( BCG ), and attenuated polio and measles. In developed countries congenerous as the US, more vaccinations are required by health authorities. However, for the so - called " herd laxity " to work, a certain % of the population must clinch with vaccination timetable.
( 3 ) Safety. Vaccination with needles produces dangerous infectious waste that come with serious health threats to both patient and health care professionals. The recycle of unsterilized needles has facilitated the transmission of blood - borne infections coextensive as HIV and hepatitis.
( 4 ) Speed and efficiency. Recently, the threats of bioterrorism and pandemic flu have highlighted the need of fast, easy and safe vaccine delivery to the body politic should the need arise. Yep, vaccination using syringes and needles was not designed for these situations.
( 5 ) Cost - efficiency and logistics. Doing away with syringes and needles can make vaccinations in less developed countries cheaper and more accessible. Syringes and needles need to be merry and stored for vaccination purposes. Injectible vaccines need to be frore during transport.
Although needle - free delivery systems materialize for many drugs, vaccines ad hoc a challenge due to they often consist of immense molecules that cannot be chewed delivered transdermally. Myron Levine summarized in a review article the different methods of administrating needle - free vaccines.
( 1 ) Vaccines delivered through mucosal surfaces. Though theoretically possible, this embodiment of delivery hasn ' t partisan on eliminate maybe with the use of the nasal drool.
( 2 ) Uttered vaccines. Specific vaccines can be disposed orally in the fashion of pills. Oral polio vaccine has ad hoc been around for awhile. Other vaccines can be delivered via this migration including certain types of cholera vaccines and the new rotavirus vaccines. However, this delivery beat presents some problems for very pubescent infants who might not be able to swallow properly and whose digestive system may not be able to withstand the effects of the vaccines.
( 3 ) Nasal vaccines. The nasal vaccine through the respiratory tract is a very popular alternative to the flu shot. The FluMist™ nasal doctor, made from live, attenuated, cold - appurtenant vaccine, has been approved by the FDA and is delivered using a single - use spraying device through the nostrils.
( 4 ) Aerosol vaccine. This mode of administration through the respiratory tract has been tested for measles vaccine. This is an alternative to the nasal wash and can be used with liquid aerosol and dry skill for mass immunization.
( 5 ) Needle - free percutaneous starless injection. This device works by propelling liquid through a small skin pore underneath high pressure. The liquid is then joyous to the dermis and underlying tissues and muscles. There are multiple dose injectors available, making this type of delivery fast and practical for mass immunizations. However, it has the disadvantage of a high incidence of local irritation at the vaccination site as well as the alternative of transmission of infectious diseases.
( 6 ) Transcutaneous delivery. This is commonly known as the " vaccine patch " and is delivered via the skin. The adhesive patch is handy after a preliminary hydration, forthwith on the skin. The occlusive patch makes the skin permeable to the vaccine. The cutaneously of use antigens are then taken up by Langerhans cells commence in the primary layer ( epidermis ) of the skin allowing the unsusceptible - processing cells to migrate to the lymph nodes.
In recent years, several biotech companies have invested millions of dollars in developing, testing and finalizing different forms of needle - free delivery systems for all kinds of drugs, not only vaccines. The most positive of the needle - free vaccination systems at this advent is Trans Cutaneuous Immunization ( TCI ).
Several advantages of the TCI have been identified. including cost - effective, safe, fast distribution, easy storage ( can be stockpiled! ) and easy administration, with the future for self - administration.
In 2007, American researchers unquestionable the skill of TCI with Clostridium gargantuan toxoid A in mice, with positive results. The bacteria C. problematic is the leading generate of nosocomial diarrhea, e. g. infectious diarrhea transmitted in the hospital setting. Also in 2007, Johns Hopkins University researchers accurate the yellow-eyed endowment of TCI with the heat - labile toxin ( LT ) of enterotoxigenic Escherichia coli ( ETEC ). The results showed that the patch " induced anti - toxin unaffected responses that did not prevent but mitigated the malady.
Apollo Life Sciences has developed and patented a needle - free drug delivery and in May 2007 it released the results of preliminary studies on needle - free transdermal delivery of tetanus toxoid vaccine in mice. Apollo has developed the non - invasive transdermal carrier, TransD™ which works by delivering " a protein - laden water layer across the skin and into the surrounding dermal and sub - dermal layers. It has quiescent to replace injections for biodrugs based on molecules twin as interferon, evolvement hormones and anti - TNF ( tumor bereavement instrument ). "
The TCI developed by the biotech determined Iomai, now owned by the Austrian company Intercell has recently made the enlightenment. Drug Delivery Report described how it works: " Administration is a two - step process. First, the skin is make-believe by placing the equipment on the patient ' s pow and pulling a tab. The tab draws a mildly abrasive substance across the skin, making a facile and halfway infinitesimal indentation and simultaneously opening an ink mark to indicate where the patch should be fruitful. The patient then wears an adhesive patch [with the vaccine] for several hours. " The productive design company Ideo helped designed the patch which required removal of an exceedingly thin layer of skin ( about one - thousandth of an inch! ).
Currently, Intercell ' s vaccine patch against traveler ' s diarrhea or the so - called Montezuma ' s Resentment is manifestation promise. The disease is a major effect of diarrhea among travelers, with symptoms ranging from intestines cramps to vomiting and diarrhea. Dr. Herbert DuPont of the University of Texas is one of the researchers involved in testing the vaccine. He told Reuters: " I imagine it ' s one of the most breathtaking new developments in travel medicine. People could buy this and put it on themselves whenever they take a trip. It is the most convenient form of immunization I have ever seen. "
The vaccine has been tested on visitors travelling to Guatemala and Mexico and showed 70 % aptitude against traveler ' s diarrhea. In also field study of 170 travelers as part of the vaccine patch Holiday II blow, the vaccine patch reduced the risk of developing moderate to severe traveler ' s diarrhea by 75 %. Coincidence III clinical tragedy are in process. If approved, this will be the first vaccine to prevent traveler ' s diarrhea. The study results were published in the Lancet and conclude that " the vaccine patch is safe and feasible, with benefits to the scale and ruckus of travellers ' diarrhea. "
A second assured Intercell vaccine patch is targeted against the pandemic flu. If booming, the patch will expand the limited vaccine supplies by allowing fewer or lower doses of vaccine. The program is funded by a United States Department of Health and Human Services contract. " The patch contains a vaccine made from the H5N1 influenza virus. Results of a Go I / II catastrophe showed that a small amount of the vaccine triggered a vigilant unaffected response in 73 % of the study participants. Phase II disaster are expected to enter upon in 2009.
Vaccination and immunization technology has changed a lot in recent years as it tries to meet the health challenges obverse both developed and developing countries. The TCI or vaccine patch is a rosy tool which will hopefully help solve some of the problems ornery natural vaccine delivery systems.
