Editing Vaccine (section)

===Subunit===
{{main|Subunit vaccine}}

Rather than introducing an inactivated or attenuated microorganism to an immune system (which would constitute a "whole-agent" vaccine), a [[Protein subunit|subunit]] vaccine uses a fragment of it to create an immune response. One example is the subunit vaccine against [[Hepatitis B#Virology|hepatitis{{spaces}}B]], which is composed of only the surface proteins of the virus (previously extracted from the [[blood serum]] of chronically infected patients but now produced by [[recombinant DNA|recombination]] of the viral genes into [[yeast]]).<ref>{{cite web|url=https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-details/vaccine-hepatitis-b-vaccine|title=A Look at Each Vaccine: Hepatitis B Vaccine|last=Philadelphia|first=The Children's Hospital of|date=18 August 2014|website=www.chop.edu|access-date=14 June 2019|archive-date=31 May 2019|archive-url=https://web.archive.org/web/20190531160201/https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-details/vaccine-hepatitis-b-vaccine|url-status=live}}</ref> Other examples include the [[Gardasil]] [[virus-like particle]] [[human papillomavirus]] (HPV) vaccine,<ref>{{cite web|url=https://www.cdc.gov/vaccines/vpd/hpv/hcp/vaccines.html|title=HPV Vaccine {{!}} Human Papillomavirus {{!}} CDC|date=13 May 2019|website=www.cdc.gov|access-date=14 June 2019|archive-date=18 June 2019|archive-url=https://web.archive.org/web/20190618034022/https://www.cdc.gov/vaccines/vpd/hpv/hcp/vaccines.html|url-status=live}}</ref> the [[hemagglutinin]] and [[neuraminidase]] subunits of the [[influenza]] virus,<ref name="historyofvaccines.org"/> and [[edible algae vaccine]]s. A subunit vaccine is being used for plague immunization.<ref>{{Cite journal|last1=Williamson|first1=E. D.|last2=Eley|first2=S. M.|last3=Griffin|first3=K. F.|last4=Green|first4=M.|last5=Russell|first5=P.|last6=Leary|first6=S. E.|last7=Oyston|first7=P. C.|last8=Easterbrook|first8=T.|last9=Reddin|first9=K. M.|date=December 1995|title=A new improved sub-unit vaccine for plague: the basis of protection|journal=FEMS Immunology and Medical Microbiology|volume=12|issue=3–4|pages=223–230|doi=10.1111/j.1574-695X.1995.tb00196.x|issn=0928-8244|pmid=8745007|doi-access=free}}</ref>