geographically and time - limited , they aim to build learning and capacity to inform country - wide implementation . between 2007 and 2011 ,
demonstration projects were the main approach to delivering new vaccines against human papillomavirus ( hpv ) to prevent cervical cancer in low - income and lower - middle - income countries ( llmics ) .
initial pilots , with vaccines donated by merck & co. , inc . or glaxosmithkline biologicals to governments and external partners , allowed countries to gain experience vaccinating adolescent girls , who were not routinely targeted for immunisation . with the exception of rwanda and bhutan , vaccine donations for national delivery
were not generally available , so demonstration projects enabled resource - poor countries to gain hpv vaccination experience . from late 2012 , gavi ,
the vaccine alliance , began supporting hpv vaccination demonstration projects or national programmes if countries had prior experience vaccinating girls aged 913 .
learn by doing. gavi provided 2-year funding for vaccines and operational costs to allow time to assess delivery strategies and potential integration with other adolescent services , develop tools , and prepare applications to gavi for national program funding . by mid-2015
, gavi had approved demonstration project funding for 25 countries , of which 6 ( 24% ) had already conducted at least one pilot , while another 3 were approved for national support . despite 55 pilots or demonstration projects being completed before 2015 , only 7 countries  and 3 more in 2015 - 2016 - transitioned from demonstration to national provision .
this article aims to examine the value of hpv vaccination demonstration projects to date , including potential drawbacks and how value for informing national scale - up might be increased , drawing from a review of published and unpublished documents from 37 countries and key informant interviews from 23 countries conducted in 2015 .
countries with data in the public domain are specifically named , while others were anonymised with an identification number .
lessons are relevant for countries intending to introduce hpv vaccination and more broadly for funders supporting introduction of new health interventions in llmics .
demonstration projects allowed both national and external partners to gain valuable experience in planning and budgeting for a new intervention , enumerating target populations , developing community acceptability and consent procedures for adolescent services , designing and piloting new reporting forms and systems , coordinating with the ministry of education for school - based vaccination , and using standardised evaluation tools . while countries had nuanced experiences and gained from the  learning by doing process , lessons from later demonstration projects generally repeated those reported earlier , indicating that while individual countries might require first - hand experience , sufficient collective learning has been generated .
first , the limited scale of projects did not allow assessment of potential health system integration , particularly as demonstration projects were often implemented outside routine services .
second , communication and social mobilisation activities had to be carefully restricted to avoid perceived inequity among those not receiving vaccination .
third ,  demonstration project was an unclear term for many stakeholders with some communities concluding that the vaccine rather than delivery method was being piloted .
fourth , many were conducted in areas primarily selected for convenience ( e.g. with higher routine vaccination coverage , more extensive infrastructure , and better education levels than national averages ) , potentially providing few lessons applicable to national scale - up .
fifth , the resource - intensive delivery strategies used in demonstration projects were potentially unsustainable once vaccine donations and external support for operational costs ended .
a focus on project evaluation and demonstrating at least 50% vaccination coverage to secure gavi support for national introduction , led some countries to choose safe options ( e.g. , school - based delivery ) known for achieving good coverage but potentially too costly to be sustainably expanded nationally .
projects in only 3 countries simultaneously or sequentially tested different vaccination venues , only 2 simultaneously tested different eligibility criteria , and only one tested different vaccination timings . as approximately 13 projects tested hpv vaccination integration ( e.g. with tetanus toxoid vaccination , deworming , vitamin a supplementation , health education ) , learning around combination interventions was largely missed .
value would increase substantially if projects were designed to learn specific lessons and inform realistic national scale - up .
for example , the prevailing  learning by doing objective appeared disconnected from learning for national scale - up , while  attaining good coverage, as a performance indicator for funding allocation , could create distortions similarly unsupportive of learning for scale - up .
instead , countries could test and cost different delivery strategies in different districts simultaneously , e.g. , school - based and health facility - based , to inform sustainable national expansion .
alternatively , donors could fund further economic modeling of different strategies to inform both demonstration projects and national scale - up .
evaluation is critical for any testing approach and cost and coverage evaluations were included in a few demonstration projects .
however , evaluations often lacked sufficient evidence to inform decision - making , with data missing or derived from pre - set grants that generally magnified operational costs .
twenty completed demonstration projects before 2015 without announcing plans to scale - up , 5 of which ceased implementing hpv vaccination without attempting to co - finance vaccine and operational costs , 2 conducted further demonstration projects , and the remainder have not indicated a decision .
implementation often stalled due to vaccine donations ending , funding constraints , or lack of ownership by national immunisation programmes .
demonstration projects may thus delay decision - making or even discourage national scale - up due to the high - cost strategies tested during the demonstration phase .
lessons from demonstration projects were not always relevant to scale - up . of seven llmics that scaled - up from demonstration to national implementation , only one reported that project lessons were useful for expansion , while another reported national expansion as more valuable for testing possible implementation strategies .
several indicated that demonstration projects were too small to inform national expansion or selected a different delivery strategy than had been tested .
of these , 3 used lessons from gardasil access program ( gap ) projects to test different delivery strategies as part of gavi - funded demonstration projects while 6 conducted multiple , sequential non - gavi projects for reasons unclear from the data . while some scale - up delays are probably due to insufficient national immunisation program engagement with early demonstration projects , an overall discontinuity exists between implementing demonstration projects and national expansion .
longer - term comprehensive planning of projects and expansion , or changing to phased national introduction approaches , could accelerate scale - up .
the pathway from demonstration to scale - up is not straightforward and major challenges to sustainability persist .
interviewees indicated that the expensive campaign - style delivery and reduced external support during scale - up challenged national expansion efforts .
however , the question remains whether demonstration projects may have become a way to delay or discourage commitment to scale - up . with many lessons already from 55 demonstration projects ,
learning may be saturated and further learning likely to be most effective during national implementation , or in the context of phased national expansion .
this would maintain political commitment to scale - up and avoid loss of integration with national health systems .
well - designed demonstration projects can test multiple delivery strategies , implementation for challenging areas and populations , and integration with national systems .
countries implementing new interventions benefit through  learning by doing and may need initial experiences to hone social mobilisation , delivery strategies , and reporting .
however , demonstrations can distract momentum from national introduction and designs that test alternative scalable options are thus crucial .
demonstration projects were valuable when hpv vaccine was first offered to llmics before national funding was available
. however , with many lessons already documented , few new lessons observed , and additional funding available , their value has decreased .
projects were designed to  demonstrate whether llmics could implement hpv vaccination rather than whether they could implement it sustainably and at scale . while the latter is crucial , countries were reportedly reluctant to risk experimenting and potentially lose funding . in the example of hpv vaccination , initial demonstration projects quickly provided consistent lessons .
however , scale - up is critical to maximise health impact , and further demonstrations could distract momentum and decision - making .
any new demonstration projects should have guidelines that maximise value for national implementation , and flexibility for phased transition to national scale - up , without repeated funding applications .
thus , introduction of vaccines or other interventions , particularly those involving new target groups or delivery strategies , needs flexible funding approaches so that pilots can address specific questions of scalability and sustainability .
lessons from hpv vaccine introduction are relevant for other potential interventions that may be introduced in the coming years ( e.g. , menacwy vaccine , rts , s vaccine ) .
nh , smj , kg and sk contributed to data collection , analysis , and interpretation .
dwj , dsl , ug , hb and smj designed the study and contributed , along with mf , to data interpretation and critical review .
the findings and conclusions contained within are those of the authors and do not necessarily reflect positions or policies of the bill & melinda gates foundation or path .
 abstractdemonstration projects or pilots of new public health interventions aim to build learning and capacity to inform country - wide implementation . 
 authors examined the value of hpv vaccination demonstration projects and initial national programmes in low - income and lower - middle - income countries , including potential drawbacks and how value for national scale - up might be increased . 
 data from a systematic review and key informant interviews , analyzed thematically , included 55 demonstration projects and 8 national programmes implemented between 2007 - 2015 ( 89  years ' experience ) . 
 initial demonstration projects quickly provided consistent lessons . 
 value would increase if projects were designed to inform sustainable national scale - up . 
 well - designed projects can test multiple delivery strategies , implementation for challenging areas and populations , and integration with national systems . 
 introduction of vaccines or other health interventions , particularly those involving new target groups or delivery strategies , needs flexible funding approaches to address specific questions of scalability and sustainability , including learning lessons through phased national expansion . 
Introduction
Value and drawbacks of demonstration projects
Increasing the value of demonstration projects for national scale-up
Conclusions
Disclosure of potential conflicts of interest
Acknowledgements
Author contributions
Funding