New bivalent polio vaccine simplifies logistics in hard-to-reach areas

New bivalent polio vaccine simplifies logistics in hard-to-reach areasby Ian Lewis, UNICEF Supply Division Since 2005, the Global Polio Eradication Initiative (GPEI) has increasingly used monovalent oral polio vaccines (OPVs) in the fight against the two wild poliovirus strains still in circulation (wild poliovirus types 1 and 3 [WPV1 and WPV3]). These vaccines have up to three times the efficacy of the traditionally used trivalent OPV and have been a strategic tool in reducing transmission of the virus to record lows in key historic reservoirs—areas where the disease continues to exist and eradication is a challenge. To complement the large-scale use of monovalent OPVs, a new bivalent OPV has now been developed. This new vaccine is poised to accelerate progress towards a polio-free world as it simultaneously targets both WPV1 and WPV3 in one dose, while the monovalent OPVs, although potent, can only tackle one serotype at a time. A clinical trial was conducted in 2009 in India and found that bivalent OPV was clearly superior to trivalent OPV, and almost as good as the respective monovalent OPVs. The big advantage, of course, is that bivalent OPV combines the impact of the monovalent vaccines with the logistical advantage of only having to deliver a single product to target both remaining serotypes. On December 7, 2009, 4 million doses of the newly developed bivalent OPV arrived in Afghanistan from Belgium, making Afghanistan the first country in the world to receive and use the new vaccine. Planning by the government of Afghanistan and its partners, which included ensuring adequate storage space and outreach capacity with the supply chain, enabled the vaccine to be widely distributed during an immunization campaign targeting some 2.8 million children under the age of five years in areas where the crippling disease remains endemic. The distribution of bivalent OPV in Afghanistan was the culmination of an unprecedented collaboration between the United Nations Children’s Fund (UNICEF), the World Health Organization (WHO), vaccine suppliers, and other development partners under the oversight of national regulatory authorities, which saw the vaccine developed and delivered in record time. As with all polio vaccines procured through UNICEF, the new bivalent OPV comes standard with a vaccine vial monitor, a small sticker that changes color with cumulative exposure to heat, allowing health care workers to ensure the vaccine they are giving has not been damaged by heat exposure after its long journey from the manufacturer to the remotest of health posts. In May 2009, UNICEF issued a tender for 745 million doses, covering anticipated demand starting in the third quarter of 2009 through 2010. This was in anticipation of a positive recommendation by the Advisory Committee on Poliomyelitis Eradication—the global technical advisory body of the GPEI—for use of the vaccine. The recommendation came in June 2009, immediately after the clinical trials were concluded. The first vaccine (from GlaxoSmithKline [GSK]) was licensed in early October 2009 and subsequently prequalified by WHO within three weeks. As UNICEF already had valid offers, an award was made to GSK in mid-November 2009—three weeks after prequalification. A second bivalent OPV product (from Panacea) was prequalified by WHO on December 10, 2009, and awarded less than two weeks after that. The first delivery of 16 million doses for immunization campaigns in India followed on January 6, 2010. It is expected that additional bivalent OPVs will be prequalified by WHO in the first quarter of 2010. Other countries will now also benefit from the new bivalent OPV. Sixty million doses have already been delivered to Nigeria, and the new vaccine is also expected to play a major role in countries at high risk of polio importations by simultaneously protecting populations from both WPV1 and WPV3. For further information on bivalent OPV and the GPEI, please visit: www.polioeradication.org. We invite you to comment on or post a question relating to this article by clicking the “post reply” button on this page. You will have to log in or register; the process is very simple. Return to the Optimize newsletter.