WordNet

pursue a positive and satisfying existence; "You must accept yourself and others if you really want to live"
actually being performed at the time of hearing or viewing; "a live television program"; "brought to you live from Lincoln Center"; "live entertainment involves performers actually in the physical presence of a live audience" (同)unrecorded
abounding with life and energy; "the club members are a really live bunch"
charged with an explosive; "live ammunition"; "a live bomb"
exerting force or containing energy; "live coals"; "tossed a live cigarette out the window"; "got a shock from a live wire"; "live ore is unmined ore"; "a live bomb"; "a live ball is one in play"
highly reverberant; "a live concert hall"
in current use or ready for use; "live copy is ready to be set in type or already set but not yet proofread"
lead a certain kind of life; live in a certain style; "we had to live frugally after the war"
not recorded; "the opera was broadcast live"
of current relevance; "a live issue"; "still a live option"
true to life; lifelike; "the living image of her mother"
people who are still living; "save your pity for the living"
(informal) absolute; "she is a living doll"; "scared the living daylights out of them"; "beat the living hell out of him"
(used of minerals or stone) in its natural state and place; not mined or quarried; "carved into the living stone";
pertaining to living persons; "within living memory"
still in active use; "a living language"
become weaker, in strength, value, or magnitude
reduced in strength; "the faded tones of an old recording" (同)attenuated, faded, weakened
immunogen consisting of a suspension of weakened or dead pathogenic cells injected in order to stimulate the production of antibodies (同)vaccinum
of an electrical signal; reduced in amplitude with little or no distortion

PrepTutorEJDIC

『生きている』,生命がある / 《副詞[句]を伴って》〈人などが〉『生き続ける』 / 〈物事が〉長く続く,存続する / 《場所を表す副詞[句]を伴って》〈人などが〉『住む』,居住する / 《副詞[句]を伴って》『生活する』,暮らす / 生人を楽しむ,おもしろく桟らす / 《a+形容詞癌lifeを目的語にして》〈…を生活〉‘を'する / 〈思想など〉‘を'実銭する
《名詞の前にのみ用いて》『生きている』 / 『活気のある』 / (問題などが)当面の / 燃えている / (弾丸などが)まだ爆発してない,未発の / まだ動いている(働いている),有効な / 電流が通じている / (放走が)生の,実況の
『生きている』 / 生活の;生活に適した / 『現存の』,まだ使われている / 『生き生きした』,活気のある / 『生き写しの』 / 〈U〉生存;生活状態,暮らし / 〈U〉《a~,one's~》『生計』,暮らしの費用(livelihood) / 《the~》《複数扱い》生きている人々
〈固体など〉'を'細くする;〈体など〉'を'やせさせる / 〈力・価値など〉'を'減じる,弱める
牛痘種,痘苗(牛痘を起こすビールスで,天然痘予防のために人体に接種される) / (伝染病の病原菌から作った)ワクチン

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/03/27 13:32:10」(JST)

wiki en

An attenuated vaccine is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or "live").^[1] Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent. These vaccines contrast to those produced by "killing" the virus (inactivated vaccine).

Examples

Examples of "live" (example attenuated) vaccines include:

Viral: measles vaccine, mumps vaccine, rubella vaccine, Live attenuated influenza vaccine (the seasonal flu nasal spray and the 2009 H1N1 flu nasal spray), chicken pox vaccine, oral polio vaccine (Sabin), rotavirus vaccine, and yellow fever vaccine.^[2] Rabies vaccines are now available in two different attenuated forms, one for use in humans, and one for animal usage.
Bacterial: BCG vaccine,^[2] typhoid vaccine^[3] and epidemic typhus vaccine.

Development

Viruses may be attenuated via passage of the virus through a foreign host, such as:

Tissue culture
Embryonated eggs
Live animals

The initial virus population is applied to a foreign host. One or more of these will possess a mutation that enables it to infect the new host. These mutations will spread, as the mutations allow the virus to grow well in the new host; the result is a population that is significantly different from the initial population, and thus will not grow well in the original host when it is re-introduced (hence is "attenuated"). This process is known as "passage" in which the virus becomes so well adapted to the foreign host that it is no longer harmful to the vaccinated subject. This makes it easier for the host's immune system to eliminate the agent and create the immunological memory cells which will likely protect the patient if they are infected with a similar version of the virus in "the wild".

Administration

In an attenuated vaccine, live virus particles with very low virulence are administered. They will reproduce, but very slowly. Since they do reproduce and continue to present antigen beyond the initial vaccination, boosters are required less often. These vaccines are produced by growing the virus in tissue cultures that will select for less virulent strains, or by mutagenesis or targeted deletions in genes required for virulence. There is a small risk of reversion to virulence; this risk is smaller in vaccines with deletions. Attenuated vaccines also cannot be used by immunocompromised individuals.

Advantages of attenuated vaccines

Activates all phases of the immune system (for instance IgA local antibodies are produced)^{[citation needed]}
Provides more durable immunity; boosters are required less frequently^{[citation needed]}
Low cost^{[citation needed]}
Quick immunity^{[citation needed]}
Easy to transport/administer (for instance OPV for Polio can be taken orally, rather than requiring a sterile injection by a trained healthworker, as the inactivated form IPV does)^{[citation needed]}
Vaccines have strong beneficial non-specific effects. That is effects which go beyond the specific protective effects against the targeted diseases.^[4]

Disadvantages of attenuated vaccines

Secondary mutation can cause a reversion to virulence.^[5]
Can cause severe complications in immunocompromised patients.^[6]
Can be difficult to transport due to requirement to maintain conditions (e.g. temperature)

References

^ Badgett MR, Auer A, Carmichael LE, Parrish CR, Bull JJ (October 2002). "Evolutionary dynamics of viral attenuation". J. Virol. 76 (20): 10524–9. doi:10.1128/JVI.76.20.10524-10529.2002. PMC 136581. PMID 12239331.
^ ^a ^b "Immunization". Archived from the original on 7 March 2009. Retrieved 2009-03-10.
^ Levine, Myron M.; Ferreccio, Catterine; Black, Robert E.; Lagos, Rosanna; Martin, Oriana San; Blackwelder, William C. (July 15, 2007). "Ty21a Live Oral Typhoid Vaccine and Prevention of Paratyphoid Fever Caused by Salmonella enterica Serovar Paratyphi B". Clinical Infectious Diseases 45 (Supplement 1): S24–S28. doi:10.1086/518141. ISSN 1058-4838. PMID 17582564.
^ Benn, Christine S.; Netea, Mihai G.; Selin, Liisa K.; Aaby, Peter (September 2013). "A small jab – a big effect: nonspecific immunomodulation by vaccines". Trends in Immunology (Elsevier) 34 (9): 431–439. doi:10.1016/j.it.2013.04.004. PMID 23680130.
^ Shimizu H, Thorley B, Paladin FJ; et al. (December 2004). "Circulation of type 1 vaccine-derived poliovirus in the Philippines in 2001". J. Virol. 78 (24): 13512–21. doi:10.1128/JVI.78.24.13512-13521.2004. PMC 533948. PMID 15564462.
^ Kroger, Andrew T.; Ciro V. Sumaya; Larry K. Pickering; William L. Atkinson (2011-01-28). "General Recommendations on Immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP)". Morbidity and Mortality Weekly Report (MMWR) (Centers for Disease Control and Prevention). Retrieved 2011-03-11.

External links

Global Polio Eradication Initiative: Advantages and Disadvantages of Vaccine Types
CDC H1N1 Flu / 2009 H1N1 Nasal Spray Vaccine Q&A at the website of the US Centers for Disease Control and Prevention

UpToDate Contents

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1. Immunizations in patients with cancer
2. 健康成人における予防接種に対するアプローチ approach to immunizations in healthy adults
3. 妊娠中の予防接種 immunizations during pregnancy
4. 小児における季節性インフルエンザ：ワクチン接種による予防 seasonal influenza in children prevention with vaccines
5. 成人における季節性インフルエンザワクチン seasonal influenza vaccination in adults

English Journal

Longevity of B-cell and T-cell responses after live attenuated influenza vaccination in children.

Mohn KG1, Bredholt G1, Brokstad KA2, Pathirana RD1, Aarstad HJ3, Tøndel C4, Cox RJ5.
The Journal of infectious diseases.J Infect Dis.2015 May 15;211(10):1541-9. doi: 10.1093/infdis/jiu654. Epub 2014 Nov 25.
BACKGROUND: The live attenuated influenza vaccine (LAIV) is the preferred vaccine for children, but the mechanisms behind protective immune responses are unclear, and the duration of immunity remains to be elucidated. This study reports on the longevity of B-cell and T-cell responses elicited by the
PMID 25425696

A novel non-integrative single-cycle chimeric HIV lentivector DNA vaccine.

Moussa M1, Arrode-Brusés G1, Manoylov I1, Malogolovkin A1, Mompelat D1, Ishimwe H1, Smaoune A1, Ouzrout B1, Gagnon J1, Chebloune Y2.
Vaccine.Vaccine.2015 May 5;33(19):2273-82. doi: 10.1016/j.vaccine.2015.03.021. Epub 2015 Mar 28.
Novel HIV vaccine vectors and strategies are needed to control HIV/AIDS epidemic in humans and eradicate the infection. DNA vaccines alone failed to induce immune responses robust enough to control HIV-1. Development of lentivirus-based DNA vaccines deficient for integration and with a limited repli
PMID 25825333

Rabies vaccine preserved by vaporization is thermostable and immunogenic.

Smith TG1, Siirin M2, Wu X3, Hanlon CA3, Bronshtein V2.
Vaccine.Vaccine.2015 May 5;33(19):2203-6. doi: 10.1016/j.vaccine.2015.03.025. Epub 2015 Mar 23.
A rabies vaccine that is thermostable over a range of ambient environmental temperatures would be highly advantageous, especially for tropical regions with challenging cold-chain storage where canine rabies remains enzootic resulting in preventable human mortality. Live attenuated rabies virus (RABV
PMID 25812841

Japanese Journal

臨床研究・症例報告『はしか風しん混合生ワクチン「北里第一三共」』の安全性の検討 : 使用成績調査結果

後藤佑樹,福島寿宣,木下麻衣 [他]
小児科臨床 68(2), 281-291, 2015-02
NAID 40020328576

N-pro of classical swine fever virus contributes to pathogenicity in pigs by preventing type I interferon induction at local replication sites

Tamura Tomokazu,Nagashima Naofumi,Ruggli Nicolas,Summerfield Artur,Kida Hiroshi,Sakoda Yoshihiro
Veterinary Research 45, 2014-04-17
… During the establishment of the live attenuated CSF vaccine strain GPE(-), N-pro acquired a mutation that abolished its capacity to bind and degrade IRF3, rendering it unable to prevent IFN-alpha/beta induction. … In a previous study, we showed that the GPE(-) vaccine virus became pathogenic after forced serial passages in pigs, which was attributed to the amino acid substitutions T830A in the viral proteins E2 and V2475A and A2563V in NS4B. …
NAID 120005446631

Modulation of systemic and mucosal immunity against an inactivated vaccine of Newcastle disease virus by oral co-administration of live attenuated Salmonella enterica serovar Typhimurium expressing chicken interleukin-18 and interferon-α

RAHMAN Md. Masudur,UYANGAA Erdenebelig,HAN Young Woo,HUR Jin,PARK Sang-Youel,LEE John Hwa,KIM Koanhoi,EO Seong Kug
Journal of Veterinary Medical Science, 2014
… Here, we investigated the systemic and mucosal immunomodulatory properties of oral co-administration of chicken interleukin-18 (chIL-18) and chicken interferon-α (chIFN-α) using attenuated Salmonella enterica serovar Typhimurium on an inactivated ND vaccine. …
NAID 130004704148