Spain and Germany want to return excess swine flu vaccine/ Reuters

According to Reuters via the One Click Group, alternatively these countries could resell vaccine to other countries if manufacturers will not accept vaccine back.

"... The Geneva-based WHO is coordinating efforts to encourage rich countries to
share vaccines with poorer nations who had little or no access to supplies.
Fukuda said six manufacturers and 12 countries had so far pledged some 180
million doses of vaccines to be distributed to around 95 countries.
Officials at the drug companies had no immediate comments on the German and Spanish government moves."