Vaccine stockouts around the world: Are essential vaccines always available when needed?

As countries rise to the challenge of implementing the priorities of this "Decade of Vaccine" and their commitments delineated in the Global Vaccine Action Plan (GVAP), many continue to face important challenges of securing a continuous supply of essential vaccine for their national immunization programme. This study provides evidence on the incidence of vaccine stockouts in countries, their root causes and their potential impact on service delivery.

Vaccine stockout indicators collected from the WHO-UNICEF Joint Reporting Form (JRF) and UNICEF's Vaccine Forecasting Tool were analysed for the years covering the first half of the GVAP (2011 to 2015) and using 2010 as the baseline year. While the JRF collects annual information on national and subnational stockouts by vaccine, the UNICEF Vaccine Forecasting Tool has the advantage of requesting UNICEF procuring countries to report on the reasons underpinning any stockouts.

Every year on average, one in every three WHO Member States experiences at least one stockout of at least one vaccine for at least one month. The incidence is most pronounced in Sub-Saharan Africa where 38% of countries in this area of the world report national-level stockouts. The vaccines most affected are DTP containing vaccines (often combined with HepB and Hib) and BCG. They account for respectively 43% and 31% of stockout events reported. While national level vaccine stockouts occur in countries of all income groups, middle income countries are the most affected. In 80% of cases, national level stockouts were due to reasons internal to countries. More specifically, 39% of stockouts were attributable to government funding delays, 23% were caused by delays in the procurement processes, and poor forecasting and stock management at country level accounted for an additional 18%. When a national level stockout of vaccines occurs, there is an 89% chance that a subnational stockout will occur at district level. More concerning is that if a district level stockout occurs, this will lead to an interruption of vaccination services in 96% of cases.

There continues to be important challenges of ensuring a continuous availability of essential vaccines. The global community, together with countries, urgently need to design effective interventions aimed at reducing the frequency and mitigating the impact of stockouts.