The recent shortage of the only yellow fever vaccine (YF-VAX) approved in the United States is expected to exhaust the available supply by mid-2017. In an effort to continue yellow fever immunization of travelers, Sanofi Pasteur submitted an expanded access investigational new drug (eIND) application to the Food and Drug Administration (FDA) for the importation and administration of an alternative yellow fever vaccine (Stamaril) developed by Sanofi Pasteur France. The alternative vaccine carries comparable safety and efficacy profiles to that of the US-licensed vaccine.
Yellow fever, which is transmitted through the bite of an infected mosquito, can be prevented by a live-attenuated virus vaccine that produces neutralizing antibodies in nearly all recipients (80%–100%) by 10 days post-vaccination. The yellow fever vaccine is recommended for travelers visiting areas with endemic or epidemic yellow fever virus transmission. In the US, about 500,000 doses of YF-VAX are distributed each year to immunize military and civilian travelers.
The diminishing supply of YF-VAX started in November 2015 as Sanofi Pasteur was shifting to a newer production facility set to open in 2018. A manufacturing complication led to the loss of a large quantity of doses. The Company then implemented ordering restrictions for YF-VAX to extend the supply available. The CDC was later notified of a likely depletion of YF-VAX projected for 2016.
While Sanofi Pasteur was able to manufacture additional doses of YF-VAX in late 2016, it is not enough to meet the anticipated demand during the time between permanent closure of the old facility and the opening of the new facility.
In response, a possible fractional dosing of the vaccine was proposed but it was “deemed a nonviable option” due to limited data. Sanofi Pasteur then submitted an eIND application for Stamaril, which uses the same vaccine substrain 17D-204 as YF-VAX with comparable safety and efficacy. It is supplied as single-dose and multi-dose vials. The importation and use of Stamaril in the US is not expected to significantly affect the supply intended for global use.
Part of the eIND implementation includes a 2-tiered systematic process for selecting a set number of sites to administer the vaccine. The Centers for Disease Control and Prevention (CDC) and Sanofi Pasteur will update the public with a list of locations that will be giving the replacement vaccine. As of April 2017, about 250 clinic sites were targeted for inclusion; select personnel will undergo training in April and May 2017.
Gershman MD, Angelo KM, Ritchey J, et al. Addressing a yellow fever vaccine shortage – United States, 2016-2017 [press release]. Washington DC: Centers for Disease Control and Prevention. Published April 18, 2017. Accessed May 1, 2017.
This article originally appeared on MPR