The fact that the CIA organized a fake vaccination program in 2011 to help find Osama Bin Laden is an additional cause of distrust. In 2015, the WHO announced a deal with the Taliban to encourage them to distribute the vaccine in areas they control. However, the Pakistani Taliban was not supportive. On 11 September 2016, two unidentified gunmen associated with the Pakistani Taliban, Jamaat-ul-Ahrar, shot Zakaullah Khan, a doctor who was administering polio vaccines in Pakistan. The leader of the Jamaat-ul-Ahrar claimed responsibility for the shooting and stated that the group would continue this type of attack. Such resistance to and scepticism of vaccinations has consequently slowed down the polio eradication process within the two remaining endemic countries. Travel requirements
Travellers who wish to enter or leave certain countries must be vaccinated against polio, usually at most 12 months and at least 4 weeks before crossing the border, and be able to present a vaccination record/certificate at the border checks. : 25–27  Most requirements apply only to travel to or from so-called polio-endemic, polio-affected, polio-exporting, polio-transmission, or high-risk countries. As of August 2020, Afghanistan and Pakistan are the only polio-endemic countries in the world (where wild polio has not yet been eradicated). Several countries have additional precautionary polio vaccination travel requirements, for example to and from key at-risk countries, which as of December 2020 include China, Indonesia, Mozambique, Myanmar, and Papua New Guinea.
Apart from the O-methyl group at the reducing end of the molecule, the identity and sequence of the five monomeric sugar units contained in fondaparinux is identical to a sequence of five monomeric sugar units that can be isolated after either chemical or enzymatic cleavage of the polymeric glycosaminoglycans heparin and heparan sulfate (HS). Within heparin and heparan sulfate this monomeric sequence is thought to form the high-affinity binding site for the anti-coagulant factor antithrombin (AT). Binding of heparin or HS to AT has been shown to increase the anti-coagulant activity of antithrombin 1000 fold. In contrast to heparin, fondaparinux does not inhibit thrombin. Chemistry
Abbreviations
GlcNS6S = 2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside
GlcA = β-D-glucopyranuronoside
GlcNS3,6S = 2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl
IdoA2S = 2-O-sulfo-α-L-idopyranuronoside
GlcNS6SOMe = methyl-O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranosideFondaparinux is only accessible by chemical synthesis. Recently, Supriya Dey et al. reported an effective and scalable one-pot synthesis of Fondaparinux.The sequence of monosaccharides is D-GlcNS6S-α-(1,4)-D-GlcA-β-(1,4)-D-GlcNS3,6S-α-(1,4)-L-IdoA2S-α-(1,4)-D-GlcNS6S-OMe, as shown in the following structure:

References
External links
"Fondaparinux". Drug Information Portal. U.S. National Library of Medicine.