11. It is a sterile injectable suspension of acellular cross-linked porcine collagen matrix. 12. No less an authority than Libbie Hyman weighed in on the " acellular " side. 13. The longest lasting and least risky results appear to arise from use of acellular dermis products. 14. Because of the acellular structure of their dermal skeleton, they were first regarded as heterostracans. 15. It has been suggested that all high amounts of short acellular carbohydrates are detrimental to health. 16. Another type of acellular vaccine already is used in this country for booster shots for older children. 17. The origin of the formative cementoblasts is believed to be different for cellular cementum and acellular cementum. 18. When I have a burning question on acellular pertussis vaccine, I turn to them for an update. 19. Most viral vaccines are based on live acellular components of micro-organisms, including harmless toxin components. 20. The multicomponent acellular pertussis vaccine is 71 85 % effective, with greater effectiveness for more severe strains.