How will the visual cue differ or complement the VVM that is currently used to validate vaccine potency at the point of use to vaccine recipient?

My experience in Tanzania I am quite impressed on Multi Dose Vial Policy based on the following facts: • For the past twelve years of working with National Immunization Programme and ten years of MDVP we never received claim or report of AEFI specifically on MDVP or due to MDVP so I am not worried much on the safety . However, training and quality supportive supervision remained to be critically important on MDVP. • For Low Income Developing countries; where resources are inadequate and health sector more specifically EPI is underfunded at all levels, MDVP may be one of the solutions to reduce the financial gap. Multi dose are relatively expensive, however needs relatively very small storage capacities which are expensive to procure, install, maintain and other related costs i.e transportation costs and wastes generated by single dose vials.

Hi David We should note that absence of evidence is not the same as evidence of no problem. The MDVP (re-use of certain open vials) should not lead to any infections, if correct procedures are followed. It is good to know that this appears to be the case in Tanzania, with no reports. Sadly, children have died as a result of infection from re-use of contaminated vials which were kept for longer than one session, allowing bacterial re-growth. The concern with the 2-dose PCV10 is that if kept beyond the session, it could also lead to such adverse reaction. And yes, the MDVP, by allowing for re-use can lead to substantially lowered wastage, saving not only vaccine costs but also the storage and transport costs. In general, multi-dose vials are considerably cheaper per dose than single dose vials; so even with a lot of wastage multi-dose vials can be cheaper. (In the case of PCV10, the saving comes from its reduced packed volume needs to be balanced against the wastage; but this is further complicated by the manufacturer only providing this vaccine for GAVI supply as a 2-dose.) The initial question posed was looking for countries to pilot the 'visual cue' to indicate whether it can be kept or must be discarded at the end of session. Cel1 raises a vaild point, which WHO had initially proposed: the absence of a VVM on an opened vial, could be used as a visual cue to indicate it can be kept. In other words, can only keep vials that still have a VVM after opening.

We intend the visual cue to be a marking on the vial that will indicate to the health worker if this vial should be discarded at the end of the session, or if it can be kept opened for subsequent sessions. The reason for this is that we will in future have liquid vaccines that will have to be discarded at the end of a session and reconstitued vaccines that may be kept for subsequent sessions - therefore previous practice relating to liquid and reconstituted vaccine no longer was true and we had to design a way to deal with this. By the way, the visual cue is meant to be complementary to the VVM and will operate alongside the VVM.

Visual clues: Thanks, Rudi. May be we need to understand the variability in terms of composition of the vaccine to be introduced. We have been using the MDVP for a longer period for liquid vaccines such as TT, DTP-HepB, OPV and currently Penta (the ten doses vial); probably the effectiveness and safety could be a research question for establishment of evidence based decisions, and preferably I will be interested to be engaged. However, for matter of programming, proactively quality improvement can be done through monitoring system and effective supportive supervision

Thanks, David. As you rightly point out, the safety concerns are the most important consideration when we established the multi-dose vial policy (MDVP), and that is the main reason why we are now moving to the visual cue, which will clearly indicate to the health worker if it is safe to keep multidose vials open for subsequent sessions or not. Clearly, this also remains within the context of normal antiseptic practices. I agree that the two main benefits of the functioning MDVP are a reduction in cold storage space (as you can use multi-dose vials) and the reduction of wastage (as you can use some vaccines in multidose vials until they are used up, without wastage). So this clearly leads to reduced cost in developing countries.