Vaccinations - Needle and Pain Free
Apr 5, 2009 | The HWNTeam | Cutting Edge
The development of a needle-free vaccination delivery system is one of the major challenges facing global health care today
Even though vaccinations have saved lives over the years, one of the major hurdles to overcome is the use of needles or “sharps” to deliver the vaccines. Millions of needles and syringes are used each day in health care. The World Health Organization (WHO) estimates that 12 billion injections are given each year. Only about 5% are used in the delivery of vaccines for immunization and prevention of infectious diseases.1
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 generally must be attained for maximal 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 administer vaccines without the use of 'sharps', that is, needles and syringes”.2
So, why is there a consensus to take the needle out of the vaccination equation?
Pain and irritation of vaccination site - A large fraction of our population is scared of needles, probably as consequence of a previous bad experience. The majority of patients at the delivery end of vaccination are very young children under the age of two and needle pricks in this patient population can cause a lot of pain and distress. Needles may also cause discomfort and irritation at the injection site long after the shot has been applied.
Lack 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 such as Canada, more vaccinations are required by health authorities. However, for the so-called “herd immunity” to work, a certain % of the population must comply with vaccination schedule. Lack of acceptance of needle use appears to be a big factor for lack of compliance.
Safety - Vaccination with needles produces dangerous infectious waste that come with serious health threats to both patient and health care professionals. The reuse of unsterilized needles has facilitated the transmission of blood-borne infections such as HIV and hepatitis.
Speed and efficiency - Recently, the threats of bioterrorism (e.g. anthrax in the US) and pandemic flu e.g. avian flu in Asia) have highlighted the need of fast, easy and safe vaccine delivery to the masses should the need arise. Definitely, vaccination using syringes and needles was not designed for these situations.
Cost-efficiency and logistics - Syringes and needles need to be transported and stored for vaccination purposes. Injectible vaccines need to be refrigerated during transport.
OK, what are needle-free vaccinations?
As the name implies, needle-free vaccines are vaccines delivered without a needle. Although needle-free delivery systems exist for many drugs, vaccines present a challenge because they usually consist of large molecules that cannot be easily delivered transdermally. Myron Levine summarized in a review article the different methods of administrating needle-free vaccines.
Vaccines delivered through mucosal surfaces - These are vaccines delivered through the mucosal surfaces. Though theoretically possible, this form of delivery hasn’t caught on except perhaps with the use of the nasal spray.3
Oral vaccines - pecific vaccines can be given orally in the form of pills. Oral polio vaccine has already been around for awhile. Other vaccines can be delivered via this route including certain types of cholera vaccines and the new rotavirus vaccines. However, this delivery route presents some problems for very young infants who might not be able to swallow properly and whose digestive system may not be able to withstand the effects of the vaccines.
Nasal vaccines - The nasal vaccine through the respiratory tract is a very popular alternative to the flu shot. The FluMist™ nasal spray, made from live, attenuated, cold-adapted vaccine, has been approved by the FDA and is delivered using a single-use spraying device through the nostrils.
Aerosol vaccine - This mode of administration through the respiratory tract has been tested for measles vaccine. This is an alternative to the nasal spray and can be used with liquid aerosol and dry power for mass immunization.
Needle-free percutaneous jet injection - This device works by propelling liquid through a small skin pore under high pressure. The liquid is then transported 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 possibility of transmission of infectious diseases.
Trans Cutaneuous Immunization (TCI) - The 'vaccine patch' works by making the skin permeable which results in the vaccine's antigens being easily taken up by Langerhans cells found in the upper layer (epidermis) of the skin allowing the immune-processing cells to migrate to the lymph nodes. InterCell and Ideo appear to be the leaders in this technology.4-6
Alright, what's the current status of needle-free vaccines?7-9
In recent years, several biotech companies worldwide 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 promising of the needle-free vaccination systems at this juncture is Trans Cutaneuous Immunization (TCI). Several advantages of the TCI have been identified as:
- Fast distribution
- Easy storage (can be stockpiled!)
- Easy administration, with the potential for self-administration.
In 2007, American researchers tested the efficacy of TCI with Clostridium difficile toxoid A in mice, with positive results. The bacteria C. difficile is the leading cause of nosocomial diarrhea, e.g. infectious diarrhea transmitted in the hospital setting.10
Also in 2007, Johns Hopkins University researchers tested the protective efficacy of TCI with the heat-labile toxin (LT) of enterotoxigenic Escherichia coli (ETEC). The results showed that the patch “induced anti-toxin immune responses that did not prevent but mitigated illness following a high-dose challenge with a virulent LT+/ST+ ETEC strain”. In fact, the vaccine patch reduced the risk of developing moderate to severe traveler’s diarrhea by 75%.11,12
In May 2007, Apollo Life Sciences, an Australian company, released the results of preliminary studies on needle-free transdermal delivery of tetanus toxoid vaccine in mice. The non-invasive transdermal carrier, TransD worked by delivering a protein-laden water layer across the skin and into the surrounding dermal and sub-dermal layers. Unfortunately this company appears to have gone out of business.13
There have also been attempts by Intercell, an Austrian company, to develop a vaccine patch against traveler’s diarrhea or the so-called Montezuma's Revenge. Dr. Herbert DuPont of the University of Texas is one of the researchers involved in testing the vaccine. He told Reuters: "I think it's one of the most exciting 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% efficacy against traveler’s diarrhea.14
Intercell is also developing a vaccine patch targeted against the Pandemic influenza. Intercell states "our innovative delivery technology of a needle-free vaccine patch expands the possibility of a novel efficient vaccine which require lower or fewer doses and thereby expands limited vaccine stocks. "The Pandemic Influenza Vaccine Enhancement Patch" is currently in clinical trial.15
In 2010, researchers from the Georgia Institute of Technology and the Emory University School of Medicine reported their findings using dissolving polymer microneedle patches for influenza vaccination.16
Progress also continues on the NanoPatch and on various other fronts including the the needle-free Respiratory Syncytial Virus vaccine for babies and an Australian trial comparing the use of a new needle-free device for delivering the annual flu vaccine with standard injections.
The Bottom Line
Vaccination and immunization technology has changed a lot in recent years as it tries to meet the health challenges facing both developed and developing countries. Obviously, doing away with syringes and needles has its benefits, but more importantly it can make vaccinations in less developed countries cheaper and more accessible.
The development of a needle-free vaccination delivery system continues to be one of the major challenges facing global health care today. Perhaps the TCI or vaccine patch will hopefully help solve some of the problems facing traditional vaccine delivery systems. Time will tell.
Published April 5, 2009, updated June 3, 2012
- Develop Needle-Free Delivery Systems, Grand Challenges in Global Health
- Levine MM, Can needle-free administration of vaccines become the norm in global immunization? Nature Medicine 9, 99 - 103 (2003)
- Needle-Free Respiratory Syncytial Virus Vaccine For Babies, Medical News Today, 03 Apr 2012
- Lawson LB, Mucosal immune responses induced by transcutaneous vaccines, Curr Top Microbiol Immunol. 2012;354:19-37
- Vaccine patch could replace jabs - NHS Analysis, Patient UK
- Designing the needle-free future of vaccine delivery, IDEO
- Pinock S, Closing in on needle-free vaccines, The Australian July 02, 2011
- Study to test needle-free vaccine, BigPond News, June 1, 2012
- McKeough T, Intercell’s Needle-Free Vaccines, Fast Company, November 1, 2008
- Ghose C, Transcutaneous immunization with Clostridium difficile toxoid A induces systemic and mucosal immune responses and toxin A-neutralizing antibodies in mice, Infect Immun. 2007 Jun;75(6):2826-32
- McKenzie R, Transcutaneous immunization with the heat-labile toxin (LT) of enterotoxigenic Escherichia coli (ETEC): protective efficacy in a double-blind, placebo-controlled challenge study, Vaccine 2007 May 4;25(18):3684-91
- Frech SA, Use of a patch containing heat-labile toxin from Escherichia coli against travellers' diarrhoea: a phase II, randomised, double-blind, placebo-controlled field trial, Lancet. 2008 Jun 14;371(9629):2019-25
- Lift-off for needle-free delivery, Manufacturing Chemist, June 1, 2007
- Fox M, Needle-free vaccine may stop Montezuma's Revenge, Reuters, 12 June 2008
- The Pandemic Influenza Vaccine Enhancement Patch, Intercell
- Sullivan S, Dissolving polymer microneedle patches for influenza vaccination, Nature Medicine, Volume:16, Pages:915–920, 2010
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