Vaksin: Béda antarrépisi

 

* ''Rational attenuation'' Specific modifications or deletions of genes that confer virulence removes the pathogenicity of the microbe while still allowing an immune response to be generated. This type of rational attenuation can be viewed as creating a "live" attenuated vaccine.

* ''Vector-mediated subunit delivery'' Introducing a non-infectious, non-pathogenic subunit into a live vector can prompt an immune response without presence of the pathogen. This is called ''vector-mediated subunit delivery''. For example, rabies surface protein gene has been inserted into vaccinia virus.

* ''[[Virus-like particle]]s'' Capsid proteins of icosahedral viruses assemble without the presence of a genome. These virus-like particles are antigenically authentic, but non-infectious. This has been used for HPV-16 and HPV-18 vaccines.

 

One challenge in vaccine development is economic: many of the diseases most demanding a vaccine, including [[HIV]], [[malaria]] and [[tuberculosis]], exist principally in poor countries. Pharmaceutical firms and biotech companies have little incentive to develop vaccines for these diseases, because there is little revenue potential. Even in more affluent countries, financial returns for producing vaccines are usually minimal, and the risks are great.<ref name='market_return'>{{cite news | first=Jesse L. | last=Goodman | coauthors= | title=Statement of Jesse L. Goodman, M.D., M.P.H. Director, Center for Biologics, Evaluation and Research Before the Committee on Energy and Commerce United States House of Representatives | date=2005-05-04 | publisher= | url =http://www.fda.gov/ola/2005/influenza0504.html | work = | pages = | accessdate = 2008-06-15 | language = }}</ref>

 

 

Many researchers and policymakers are calling for a different approach, using 'pull' mechanisms to motivate industry. Mechanisms such as prizes, tax credits, or [[advance market commitments]] could ensure a financial return to firms that successfully developed a HIV vaccine. If the policy were well-designed, it might also ensure people have access to a vaccine if and when it is developed.{{Fact|date=June 2008}}

[[Kategori:Mikrobiologi]]

[[Kategori:Imunologi]]

 

[[ar:تطعيم]]

[[ca:Vacuna]]

[[cs:Vakcína]]

[[de:Impfstoff]]

[[en:Vaccine]]

[[es:Vacuna]]

[[fa:واکسن]]

[[fr:Vaccination]]

[[fur:Vacine]]

[[id:Vaksin]]

[[it:Vaccino]]

[[nl:Vaccin]]

[[no:Vaksine]]

[[pl:Szczepionka]]

[[pt:Vacina]]

[[sk:Očkovanie]]

[[sl:Cepivo]]

[[te:టీకా]]

[[th:วัคซีน]]

[[vi:Vắc-xin]]

[[zh:疫苗]]