{"id":43558,"date":"2020-05-03T18:58:19","date_gmt":"2020-05-03T15:58:19","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=43558"},"modified":"2020-05-03T18:58:19","modified_gmt":"2020-05-03T15:58:19","slug":"covid-19-hastaligina-iki-kere-yakalanilir-mi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2020\/05\/03\/covid-19-hastaligina-iki-kere-yakalanilir-mi","title":{"rendered":"COVID-19 hastal\u0131\u011f\u0131na iki kere yakalan\u0131l\u0131r m\u0131?"},"content":{"rendered":"

COVID-19 hastal\u0131\u011f\u0131na tekrar yakalan\u0131l\u0131r m\u0131? Neden baz\u0131 ki\u015filer hastal\u0131\u011f\u0131 di\u011ferlerine g\u00f6re daha a\u011f\u0131r ge\u00e7iriyor? Vir\u00fcs her k\u0131\u015f geri gelecek mi, a\u015f\u0131 i\u015fe yarayacak m\u0131? Vir\u00fcs\u00fc uzun vadede nas\u0131l idare edece\u011fiz? Ba\u011f\u0131\u015f\u0131kl\u0131k sistemi koronavir\u00fcsle alakal\u0131 en \u00f6nemli sorular\u0131n baz\u0131lar\u0131n\u0131n g\u00f6be\u011finde yer al\u0131yor. As\u0131l sorun ise koronavir\u00fcse dair \u00e7ok az \u015fey biliyor olu\u015fumuz.<\/p>\n

Ba\u011f\u0131\u015f\u0131kl\u0131k sistemi v\u00fccudun enfeksiyonlara kar\u015f\u0131 savunmada i\u015flevli olan sistemidir ve iki k\u0131s\u0131mdan olu\u015fmaktad\u0131r.<\/p>\n

Birinci k\u0131s\u0131m devaml\u0131 haz\u0131rda bekler ve v\u00fccut i\u00e7inde bir \u201cyabanc\u0131 istilas\u0131\u201d tespit edildi\u011fi anda harekete ge\u00e7er. Do\u011fu\u015ftan gelen ba\u011f\u0131\u015f\u0131kl\u0131k tepkisi (innate immune response) olarak bilinir ve i\u015flevleri aras\u0131nda enflamasyona sebep olan kimyasallar\u0131n ve enfekte h\u00fccreleri yok eden akyuvarlar\u0131n salg\u0131lanmas\u0131 yer al\u0131r. Ancak bu sistem koronavir\u00fcse \u00f6zel de\u011fildir, koronavir\u00fcse kar\u015f\u0131 ba\u011f\u0131\u015f\u0131kl\u0131k sa\u011flamayacakt\u0131r.<\/p>\n

Koronavir\u00fcse kar\u015f\u0131 ba\u011f\u0131\u015f\u0131kl\u0131k sa\u011flanmas\u0131 i\u00e7in adaptif ba\u011f\u0131\u015f\u0131kl\u0131k tepkisine ihtiya\u00e7 var. Adaptif ba\u011f\u0131\u015f\u0131kl\u0131k tepkisi, koronavir\u00fcs\u00fc durdurmak i\u00e7in hedefe y\u00f6nelik antikorlar \u00fcreten h\u00fccreleri ve h\u00fccresel tepki ad\u0131 verilen, sadece vir\u00fcsle enfekte olmu\u015f h\u00fccrelere sald\u0131ran T h\u00fccrelerini i\u00e7inde bar\u0131nd\u0131r\u0131r. Ara\u015ft\u0131rmalara g\u00f6re koronavir\u00fcs\u00fc hedef alan antikorlar\u0131n \u00fcretilmeye ba\u015flanmas\u0131 yakla\u015f\u0131k 10 g\u00fcn s\u00fcr\u00fcyor ve en a\u011f\u0131r hasta olanlar en g\u00fc\u00e7l\u00fc ba\u011f\u0131\u015f\u0131kl\u0131k tepkisini g\u00f6steriyor.<\/p>\n

E\u011fer adaptif ba\u011f\u0131\u015f\u0131kl\u0131k sistemi yeterince g\u00fc\u00e7l\u00fcyse geride enfeksiyonun bir hat\u0131ras\u0131n\u0131 b\u0131rakabilir ve bu gelecekte ba\u011f\u0131\u015f\u0131kl\u0131k sa\u011flayabilir. Hafif semptomu olan veya hi\u00e7 semptom g\u00f6stermeyen ki\u015filerin yeterli bir adaptif ba\u011f\u0131\u015f\u0131kl\u0131k tepkisi geli\u015ftirip geli\u015ftiremeyecekleri hen\u00fcz bilinmiyor.<\/p>\n

Ba\u011f\u0131\u015f\u0131kl\u0131k ne kadar s\u00fcr\u00fcyor?<\/strong>
\nBa\u011f\u0131\u015f\u0131kl\u0131k sisteminin haf\u0131zas\u0131 bir nevi bizimki gibi, baz\u0131 enfeksiyonlar\u0131 net bir \u015fekilde hat\u0131rlayabiliyor, ama di\u011ferlerini unutmak gibi bir al\u0131\u015fkanl\u0131\u011f\u0131 bulunmakta.<\/p>\n

\"\"
Ba\u011f\u0131\u015f\u0131kl\u0131k a\u015f\u0131 ara\u015ft\u0131rmalar\u0131n\u0131 etkileyebilir.<\/figcaption><\/figure>\n

K\u0131zam\u0131k ba\u011f\u0131\u015f\u0131kl\u0131k sistemimiz taraf\u0131ndan hat\u0131rlanabilen bir hastal\u0131kt\u0131r, hastal\u0131\u011fa bir kere maruz kal\u0131nmas\u0131 yeterli olabilir. Ancak di\u011fer vir\u00fcslerden kaynaklanan pek \u00e7ok hastal\u0131k kolayl\u0131kla unutulabiliyor. \u00c7ocuklar zat\u00fcrre, bron\u015fiyolit gibi \u015fiddetli solunum yolu hastal\u0131klar\u0131na neden olan RSV vir\u00fcs\u00fcne ayn\u0131 k\u0131\u015f i\u00e7erisinde birden \u00e7ok defa yakalanabiliyor. SARS-CoV-2 ad\u0131 verilen yeni tip koronavir\u00fcs ise, ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n ne kadar s\u00fcre devam etti\u011fini g\u00f6rebilmemiz i\u00e7in gereken s\u00fcreci hen\u00fcz tamamlamad\u0131. Ancak insanlar \u00fczerinde etkili olan di\u011fer koronavir\u00fcsler bize ba\u011f\u0131\u015f\u0131kl\u0131k konusunda ipu\u00e7lar\u0131 verebilir. \u0130nsanlar \u00fczerinde etkili oldu\u011fu bilinen koronavir\u00fcslerden d\u00f6rd\u00fc so\u011fuk alg\u0131nl\u0131\u011f\u0131 semptomlar\u0131 sergilemekte ve bu vir\u00fcslere kar\u015f\u0131 kazan\u0131lan ba\u011f\u0131\u015f\u0131kl\u0131k k\u0131sa s\u00fcrmekte. So\u011fuk alg\u0131nl\u0131\u011f\u0131 genel olarak daha hafiftir. Ara\u015ft\u0131rmalara g\u00f6re baz\u0131 hastalar bir y\u0131l i\u00e7inde yeniden enfekte olabiliyorlar. G\u00f6rece daha etkili olan ve insanlar\u0131 etkileyebilen iki koronavir\u00fcs daha bulunmakta. Bunlar SARS ve MERS salg\u0131nlar\u0131na sebep olan koronavir\u00fcslerdir. SARS ve MERS hastal\u0131klar\u0131n\u0131n etmeni olan koronavir\u00fcslere kar\u015f\u0131 \u00fcretilen antikorlar birka\u00e7 sene sonra da tespit edilebilmi\u015fti.<\/p>\n

G\u00fcney Anglia \u00dcniversitesi\u2019nden T\u0131p Profes\u00f6r\u00fc Paul Hunter, \u201cSoru ba\u011f\u0131\u015f\u0131kl\u0131k kazan\u0131p kazanmayaca\u011f\u0131m\u0131z de\u011fil, ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n ne kadar s\u00fcrece\u011fi. Ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n \u00f6m\u00fcr boyu s\u00fcrmeyece\u011fi neredeyse kesin. Sars \u00fczerinde yap\u0131lan antikor ara\u015ft\u0131rmalar\u0131na g\u00f6re ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n sadece bir ila iki y\u0131l s\u00fcr\u00fcyor olmas\u0131 m\u00fcmk\u00fcn ancak bu hen\u00fcz kesin de\u011fil\u201d a\u00e7\u0131klamalar\u0131nda bulundu.<\/p>\n

Tamam\u0131yla ba\u011f\u0131\u015f\u0131kl\u0131k kazanm\u0131\u015f olmasan\u0131z bile ikinci bir enfeksiyonun daha hafif ge\u00e7mesi m\u00fcmk\u00fcn.<\/p>\n

COVID-19 hastal\u0131\u011f\u0131na iki kere yakalanan var m\u0131?<\/strong>
\nBaz\u0131 bireylerin k\u0131sa bir zaman aral\u0131\u011f\u0131nda birka\u00e7 koronavir\u00fcs enfeksiyonu ge\u00e7irdi\u011fine dair bildirimler mevcut. Baz\u0131lar\u0131 insanlar\u0131n ger\u00e7ekten iki kere enfekte oldu\u011funu \u00f6ne s\u00fcr\u00fcyor, bu konu hakk\u0131ndaki bir ba\u015fka d\u00fc\u015f\u00fcnce ise vir\u00fcs\u00fcn bir s\u00fcre gizlilik moduna girdikten sonra yeniden aktive oldu\u011fu y\u00f6n\u00fcnde. Ancak bilim insanlar\u0131 bunun testlerden kaynakland\u0131\u011f\u0131 ve yanl\u0131\u015fl\u0131kla insanlara vir\u00fcs\u00fc atlatmad\u0131klar\u0131 halde atlatm\u0131\u015f olduklar\u0131n\u0131n s\u00f6ylendi\u011fi sonucuna vard\u0131.<\/p>\n

\u015eu ana kadar hi\u00e7 kimse koronavir\u00fcs ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n\u0131 test etmek i\u00e7in iki kere enfekte edilmedi. Ancak bu deney bir \u00e7ift rhesus makak maymunu \u00fczerinde yap\u0131ld\u0131. Maymunlar iki kere enfekte edildiler: Birincisi ba\u011f\u0131\u015f\u0131kl\u0131k geli\u015ftirmek i\u00e7in ve ikincisi ilk enfeksiyon i\u015fleminin yap\u0131lmas\u0131ndan \u00fc\u00e7 hafta sonra. Bu \u00e7ok s\u0131n\u0131rl\u0131 deneyin sonucunda, maymunlar\u0131n h\u0131zl\u0131 bir \u015fekilde yeniden enfekte edilmelerinin ard\u0131ndan semptom geli\u015ftirmedikleri g\u00f6r\u00fcld\u00fc.<\/p>\n

Antikor varsa ba\u011f\u0131\u015f\u0131kl\u0131k da var m\u0131d\u0131r?<\/strong>
\nBunun bir garantisi yok, bu nedenle D\u00fcnya Sa\u011fl\u0131k \u00d6rg\u00fct\u00fc karantinadan \u00e7\u0131kmak i\u00e7in ba\u011f\u0131\u015f\u0131kl\u0131k onay\u0131 yoluna ba\u015fvuran \u00fclkeler konusunda tedirginlik duymakta. Fikir \u015fu \u015fekilde i\u015fliyor: E\u011fer antikor testini ge\u00e7erseniz i\u015fe gitmenizde bir sak\u0131nca g\u00f6r\u00fclm\u00fcyor.<\/p>\n

\"\"
Bir \u00e7ift rhesus maymunu.<\/figcaption><\/figure>\n

Ancak neredeyse her hastada bir miktar antikor bulsan\u0131z da hepsi e\u015fde\u011fer de\u011fil. N\u00f6tralize edici antikorlar, koronavir\u00fcse yap\u0131\u015farak vir\u00fcs\u00fcn di\u011fer h\u00fccreleri enfekte etmesini engelleyenlerdir. \u00c7in\u2019de 175 hasta \u00fczerinde yap\u0131lan bir ara\u015ft\u0131rmaya g\u00f6re hastalar\u0131n y\u00fczde 30\u2019u bu n\u00f6tralize edici antikorlara \u00e7ok d\u00fc\u015f\u00fck d\u00fczeyde sahip. Bundan dolay\u0131 D\u00fcnya Sa\u011fl\u0131k \u00d6rg\u00fct\u00fc \u201ch\u00fccresel ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n\u201d (adaptif ba\u011f\u0131\u015f\u0131kl\u0131k tepkisinin di\u011fer k\u0131sm\u0131) iyile\u015fme i\u00e7in kritik \u00f6neme sahip olabilece\u011fini belirtiyor.<\/p>\n

Bir ba\u015fka sorun ise \u015fu; antikorlar\u0131n\u0131z taraf\u0131ndan korunuyor olman\u0131z vir\u00fcs\u00fc ta\u015f\u0131y\u0131p di\u011fer insanlara bula\u015ft\u0131ramayaca\u011f\u0131n\u0131z anlam\u0131na gelmiyor.<\/p>\n

Ba\u011f\u0131\u015f\u0131kl\u0131k neden \u00f6nemli?<\/strong>
\nBa\u011f\u0131\u015f\u0131kl\u0131k, Covid-19\u2019u birden fazla defa kap\u0131p kapmayaca\u011f\u0131n\u0131z konusunda \u00f6nem ta\u015f\u0131yor. Ba\u011f\u0131\u015f\u0131kl\u0131k ayn\u0131 zamanda vir\u00fcs\u00fcn \u00f6l\u00fcmc\u00fcll\u00fc\u011f\u00fcn\u00fc de etkileyecek. \u0130nsanlar, tam olmasa bile, belli bir d\u00fczeyde ba\u011f\u0131\u015f\u0131kl\u0131klar\u0131n\u0131 korursa, hastal\u0131k daha az tehlikeli hale getirilebilir.<\/p>\n

Ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131 anlamak, kimlerin hastal\u0131\u011fa yakalanma ve yayma riski alt\u0131nda olmad\u0131\u011f\u0131 tespit edildi\u011fi takdirde, karantinadan \u00e7\u0131kma konusunda bize yard\u0131mc\u0131 olabilir. E\u011fer uzun vadeli ba\u011f\u0131\u015f\u0131kl\u0131k sa\u011flaman\u0131n zor oldu\u011fu ortaya \u00e7\u0131karsa bu, bir a\u015f\u0131 geli\u015ftirilmesini daha zor hale getirebilir veya a\u015f\u0131n\u0131n kullan\u0131m \u015feklini de\u011fi\u015ftirebilir. \u00d6mr\u00fcm\u00fczde bir kere mi a\u015f\u0131 olaca\u011f\u0131z, yoksa grip a\u015f\u0131s\u0131 gibi senelik mi? Ba\u011f\u0131\u015f\u0131kl\u0131\u011f\u0131n s\u00fcresi ister vir\u00fcs\u00fc kapma yoluyla olsun ister a\u015f\u0131yla, vir\u00fcs\u00fcn yay\u0131lmas\u0131n\u0131 durdurup durduramayaca\u011f\u0131m\u0131z\u0131 belirleyecek. Bunlar\u0131n hepsi hen\u00fcz cevab\u0131 olmayan b\u00fcy\u00fck sorulard\u0131r.<\/p>\n

Kaynak:<\/strong> https:\/\/www.bbc.com\/news\/health-52446965<\/p>\n","protected":false},"excerpt":{"rendered":"

COVID-19 hastal\u0131\u011f\u0131na tekrar yakalan\u0131l\u0131r m\u0131? Neden baz\u0131 ki\u015filer hastal\u0131\u011f\u0131 di\u011ferlerine g\u00f6re daha a\u011f\u0131r ge\u00e7iriyor? Vir\u00fcs her k\u0131\u015f geri gelecek mi, a\u015f\u0131 i\u015fe yarayacak m\u0131? Vir\u00fcs\u00fc uzun vadede nas\u0131l idare edece\u011fiz? Ba\u011f\u0131\u015f\u0131kl\u0131k sistemi koronavir\u00fcsle alakal\u0131 en \u00f6nemli sorular\u0131n baz\u0131lar\u0131n\u0131n g\u00f6be\u011finde yer al\u0131yor. As\u0131l sorun ise koronavir\u00fcse dair \u00e7ok az \u015fey biliyor olu\u015fumuz. Ba\u011f\u0131\u015f\u0131kl\u0131k sistemi v\u00fccudun enfeksiyonlara […]<\/p>\n","protected":false},"author":2027,"featured_media":43559,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[2777,1194,5848,6512],"class_list":["post-43558","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-asi","tag-bagisiklik","tag-covid-19","tag-rhesus-maymunu"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t