Although more effective than the WC vaccine, the BS-WC vaccine has not been adopted for manufacture by developing world countries primarily because the CTB component is difficult to manufacture and include in the vaccine in the doses needed to induce significant immune responses.
It is difficult to manufacture in sufficient quantities, particularly at a cost low enough to serve the hundreds of millions of people who need it each year.
Since it is difficult to manufacture tubes that are consistent in these qualities, the result, for carbon, is a mixture in which some tubes are semiconductors and some are not.
The manufacture of an efficient extremity is difficult because of the small thickness, and often generates imperfections and tearing.
Even if the reef is design as a complex structure, it is difficult to manufacture by concrete.
However, such a continuously graded CL is difficult to manufacture due to lack of commercially available techniques and associated costs.
However, it is difficult to manufacture crystalline Si thin films in large quantity by using traditional wire cutting process due to their brittleness.
In vacuum infusion (VI), it is difficult to manufacture a composite part with small dimensional tolerances, since the thickness of the part changes during resin injection.
This kind of part is difficult to be manufactured only in one stage.
