1. Omesh K. Bharti
  2. Announcements
  3. Friday, 05 November 2010
Dear Sir,Based on the PATH report, we must immediately demand from DCGI office or GOI for use of IPV through Intradermal Route as well, otherwise people would be cheated as they have been with Rabies vaccine. Though I disagree with the report on one point that is a device is required for effective delivery of vaccine as this can be done with needle and syringe as well in India as we are doing with BCG/ ARV. also I disagree with the report that the needle syringe method would cost more, especially the costs calculated for disposal of waste are not appropriate. What, important is the delivery of vaccine through intradermal method. Read the report... In this report, results are presented from an economic model that calculates the costs involved in delivering IPV vaccine in Indian immunization clinics according to the first three strategies listed above. The model analyzed the costs associated with four delivery devices: disposable needle and syringe, disposable-syringe jet injectors (DSJI), an ID adapter (which controls the depth and angle of the ID injection), or a syringe-mounted hollow microneedle (MN). Clinical trials have shown that IDD of reduced doses (delivering 20% of the volume of a standard dose) can be sufficiently immunogenic. The results of the economic analysis suggest that IDD of IPV using needle and syringe, DSJI, or ID adapter could result in cost savings of up to 71%–73% per immunized infant compared with delivery of the standard dose via the usual intramuscular (IM) route using needle and syringe. Combining IPV with adjuvant so that only 10% of the original antigen content was needed, whilst still using the IM route, had the potential to save 82% to 83% of the immunization costs, depending upon the delivery device used. An aim of this strategy is to reduce the amount of vaccine antigen required to induce a protective immune response by intradermal (ID) delivery of fractional or reduced doses, i.e., administering a smaller volume of the existing formulation. If this could be achieved for IPV, it would have the potential to stretch the manufacturing capacity of existing IPV facilities and also to reduce the manufacturing cost per dose. Some logistics costs might also be reduced as it is possible that a lower-volume dose would require less space in the cold chain during distribution and storage.Intradermal delivery (IDD) of fractional doses has been investigated for a number of vaccines, most notably rabies, influenza, and hepatitis B.* Three studies of IDD of fractional doses of IPV have been published: * Reviewed in Intradermal Delivery of Vaccines. A review of the literature and the potential for development for use in low- and middle-income countries. PATH, August 2009. http://www.path.org/files/TS_opt_idd_review.pdf.IDD of reduced doses (20% of the standard volume and therefore 20% of the standard antigen content) induced striking antibody responses in adults and children who had previously been immunized.[14] No IM comparator arm was included in this trial. A schedule of two ID doses (20% of the standard dose) in nonimmune subjects resulted in a seroconversion index of 82% which was described as being comparable to an index of 91% seen in a previous study following two IM doses.[15] Nirmal et al.[16] reported that two or three 0.1 ml doses ID were equivalent in terms of seroconversion to two 0.5 ml doses of IPV delivered IM in a previous study. The overall seroconversion rates to all three poliovirus types were 85.5% and 89.0% following two or three ID doses, respectively. Seroconversion was seen in all infants (following either two or three ID doses) who did not have maternal antibodies present in prevaccination sera.[16] More recently, two GPEI-sponsored trials used the Biojector 2000® disposable syringe jet injector (DSJI) device to deliver a 20% dose ID compared with full-dose IM.5 Two different immunization schedules were tested, one in each of the two countries (Oman and Cuba) selected to run the study, and vaccines from two different suppliers were used. Thanks, Dr. Omesh Kumar BhartiM.B.B.S.,D.H.M.,M.A.E.(Epidemiology)Directorate of Health Safety and Regulation, SHIMLA, Himachal Pradesh, India.+91-9418120302[[email protected]][email protected][/email]; [email protected]
Accepted Answer Pending Moderation
Dear Dr Bharti Thank-you for your comments on our report on intradermal (ID) delivery of IPV and strategies to reduce the cost of IPV immunization. We are pleased to see your enthusiasm for this route for vaccine delivery and the potential benefits it can offer. PATH is actively working on projects and devices to advance the use of ID delivery where appropriate. But we are very aware that there are operational issues that need to be resolved before ID delivery of IPV can be implemented; among these is the important question of the immunization schedule. The data from the clinical trials of ID delivery of reduced doses of IPV that were conducted in Cuba (Resik et al 2010) and Oman (Mohammed et al 2010) suggest that the timing of the IPV immunizations can have a significant impact on the seroconversion rate. An important next step could be to confirm these findings in other settings. You raise the issue about cost and need for devices for ID delivery. The analysis in our report suggests that use of needle and syringe for ID delivery might in fact be very slightly less expensive than using needle free jet injectors, or the depth-limiting ID adapter. We agree with you that needle and syringes are being used successfully for ID delivery of rabies vaccines, however the actual or perceived challenge of the needle and syringe based technique may still represent a barrier to fully realizing the benefit of ID delivery. The ID adapter is a very low cost device designed to make ID injections simpler and to improve the reproducibility and effectiveness of ID injections. Jet injectors have the additional advantage of avoiding needle use and the costs and hazards associated with needle-stick injuries; in the studies by Resik et al and Mohammed et al, there was a strong preference from the parents of vaccinated infants for jet injectors over needles and syringes. The value of using these, or other, devices should also be evaluated in clinical trials. Kind regards Darin Zehrung and Julian Hickling
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