Cov theem tshiab ntawm kev sib kis: kab mob txaus ntshai "Delta"

2024 Tus sau: Seth Attwood | [email protected]. Kawg hloov kho: 2023-12-16 16:06

Tus kab mob Indian tshiab COVID-19, uas twb muaj npe los ntawm cov kws tshawb fawb "Delta", tau nthuav tawm lub nthwv dej thib peb ntawm kev sib kis thoob plaws ntau lub tebchaws. Hauv New Delhi nws tus kheej, qhov xwm txheej tsuas yog kev puas tsuaj loj - 30,000 tus neeg mob ib hnub. Cov koom haum pib kawm "Delta" thiab tam sim ntawd suab lub tswb.

Cov kab mob tshiab tau hloov pauv tsis yog tsuas yog kis tau yooj yim xwb, tab sis kuj tsis tshua muaj kev tiv thaiv kab mob. Qhov no txhais tau hais tias nws tuaj yeem tiv thaiv "kev tawm tsam" uas peb lub cev tiv thaiv kab mob yuav ua rau nws.

Thaum qhov sib txawv ntawm tus kabmob coronavirus, tam sim no hu ua "Delta", thawj zaug tshwm sim hauv Indian lub xeev Maharashtra thaum Lub Kaum Ob Hlis 2020, nws tsis tau pom tias muaj dab tsi tshwj xeeb. Tab sis thaum nws tsoo New Delhi ob peb lub hlis tom qab, qhov tshwm sim yog qhov kev puas tsuaj loj tshaj plaws, muaj ze li 30,000 tus neeg mob txhua hnub thaum lub Plaub Hlis kawg. Anurag Agrawal, tus thawj coj ntawm lub koom haum ntawm Genome thiab Integrative Biology hauv New Delhi hais tias "Tam sim ntawd, nws tau pib tswj hwm thiab rhuav tshem tag nrho Alpha hom, uas txog thaum ntawd tau nthuav dav tshaj plaws hauv nroog,"

New Delhi zoo li tsis zoo li yuav ntsib lwm qhov tshwm sim loj, Agrawal tau hais tias, vim tias ntau tus neeg nyob hauv nws muaj mob lossis txhaj tshuaj tiv thaiv. Tab sis nws tau muab tawm tias cov kev tiv thaiv tiv thaiv Delta tsis muaj zog. Nws kis tau ntau dua thiab khiav tawm ntawm lub cev tiv thaiv kab mob, nws hais tias: "Lub phab ntsa peb-meter ib ncig ntawm lub nroog zoo li tau hloov mus ua ib nrab-meter ib, dhau qhov uas nws tsis yooj yim rau kev hla."

Los ntawm New Delhi, tus kab mob kis tau sai heev thiab tam sim no zoo li tau cheb lub ntiaj teb nrog lub nthwv dej tshiab, kev puas tsuaj loj. Hauv tebchaws Askiv, Delta twb suav txog ntau dua 90% ntawm cov neeg mob tshiab: qhov no tau ua rau tus lej ntawm tus kabmob coronavirus dhia dua tom qab poob qis, thiab lub lim tiam dhau los tsoomfwv tseem yuav tsum tau ncua sijhawm kawg ntawm nws txoj haujlwm qhib ciam teb.. Qhov tshwm sim ntawm Delta hauv Lisbon tau yuam tsoomfwv Portuguese kom txwv txoj kev mus ncig peb hnub ntawm lub nroog thiab lwm lub tebchaws.

Txog thaum kawg ntawm Lub Yim Hli, qhov kev xaiv no yuav suav txog li 90% ntawm txhua tus neeg mob tus kabmob coronavirus hauv European Union, tus thawj coj ntawm European Center for Disease Prevention and Control Andrea Ammon tau ceeb toom hnub no. Nws tau hais tias "Nws muaj feem ntau tias tus kab mob Delta yuav kis tau thoob plaws lub caij ntuj sov, tshwj xeeb tshaj yog cov tub ntxhais hluas uas tsis yog ib feem ntawm kev txhaj tshuaj tiv thaiv kab mob," nws hais tias "Qhov no tuaj yeem ua rau cov pej xeem muaj kev pheej hmoo ntau dua tuaj yeem mob hnyav lossis tuag taus. yog lawv tsis tau txhaj tshuaj tag lawm.”

Cov haiv neeg Delta tau sau tseg hauv Russia, Indonesia thiab ntau lub tebchaws. Hauv Teb Chaws Asmeskas, qhov twg qhov kev kis tus kab mob sib kis tau kwv yees tsawg kawg yog 14%, CDC tau hais rau lub Rau Hli 15 tias nws yog "kev txhawj xeeb tshaj plaws."

Qhov kev nce siab tau ua rau muaj kev tshawb fawb kom nkag siab tias yog vim li cas Delta thiaj li kis tau sai dua li lwm yam kev txhawj xeeb ntawm peb, yog tias nws muaj kev phom sij ntau dua, thiab nws cov kev hloov pauv tshwj xeeb uas ua rau muaj kev hloov pauv hauv cov protein ib puag ncig tuaj yeem ua rau muaj kev puas tsuaj loj. Kev tuaj txog ntawm Delta tau hais qhia tias tus kab mob SARS-CoV-2 tuaj yeem hloov kho thiab hloov zuj zus mus rau lub hlis thiab xyoo tom ntej.

Lub sijhawm tam sim no, Delta ua rau muaj kev hem thawj tshwj xeeb rau cov tebchaws txom nyem tshaj plaws, uas nws nkag mus rau cov tshuaj tiv thaiv yog txwv lossis tsis tuaj yeem ua tiav, hais tias Sumya Shwaminathan, tus kws tshaj lij kws tshaj lij rau World Health Organization. "Dab tsi uas kuv txhawj xeeb tshaj plaws yog qhov yuav tshwm sim thaum Delta mus rau Africa," nws hais.

Ib txoj kev tshawb fawb los ntawm Public Health England tau hais txog qhov muaj peev xwm loj hlob ntawm Delta. Piv rau Alpha, uas tau tsim tawm hauv tebchaws Askiv xyoo 2020, "peb muaj 50% lossis 100% ntau dua," hais tias Adam Kucharski, tus tsim qauv tsim ntawm London Tsev Kawm Ntawv Kev Noj Qab Haus Huv thiab Tshuaj Kho Mob.

Tab sis Kuharsky tseem hais tias qhov txo qis ntawm kev tiv thaiv los ntawm cov tshuaj tiv thaiv tuaj yeem cuam tshuam. Cov tshuaj tiv thaiv Pfizer-BioNTech thiab AstraZeneca muab kev tiv thaiv me ntsis tiv thaiv cov tsos mob ntawm tus kab mob tshiab nrog rau cov kab mob Alpha, raws li cov ntaub ntawv los ntawm Askiv thiab Scotland. Cov neeg uas txhaj tshuaj tsuas yog ib qho tshwj xeeb uas muaj kev phom sij - zoo li muaj ntau hauv UK. (Ob koob tshuaj ib yam tshuaj tiv thaiv tseem yuav muab tib theem siab tiv thaiv kev mus pw hauv tsev kho mob, txawm tias tawm tsam Delta.) Lwm cov tshuaj tiv thaiv zoo npaum li cas thoob ntiaj teb tiv thaiv tsis paub meej, thiab muaj pov thawj me me ntawm kev tiv thaiv cov neeg uas tau zoo los ntawm nthwv dej ntawm tus kabmob coronavirus.

Ob leeg ntawm cov teebmeem no - nce kev sib kis thiab kev tiv thaiv kev tiv thaiv - yog qhov nyuaj rau kev sib cais ntawm ib leeg, tab sis lub taub hau ntawm Wellcome Trust, Jeremy Farrar, ntseeg tias kev sib kis yog tom qab Delta dhia, tsis yog kev tiv thaiv kev tiv thaiv. "Yog tias Alpha muaj li 50% ntau dua kis tau zoo dua li cov kab mob ntuj, thiab Delta yog 50%, ces peb tab tom tham txog tus kab mob uas kis tau ob zaug dua li tus kab mob qub," piav qhia tus kws kho mob evolutionary los ntawm Oxford Aris Katzourakis University.

Qhov no yuav txhais tau tias cov tebchaws thiab cov pejxeem uas muaj cov tshuaj tiv thaiv tsawg tuaj yeem ntsib cov kabmob tshiab loj. Kuharski hais tias "Yog tias qhov kis tau sai dua yog vim tus kab mob ua rau muaj kev cuam tshuam, ces qhov no yog xov xwm phem rau lwm tus hauv ntiaj teb," Kuharski hais.

Ntxiv rau qhov ntawd, Delta muaj feem ntau xa cov pej xeem tsis tau txhaj tshuaj mus rau tsev kho mob dua li Alpha. Cov ntaub ntawv ntxov los ntawm UK qhia tias qhov kev pheej hmoo ntawm kev mus pw hauv tsev kho mob tuaj yeem yog ob zaug siab dua. Ua ke, cov yam ntxwv no tuaj yeem ua rau muaj teeb meem loj hauv Africa, Schwaminathan tau hais. “Yuav tsis muaj oxygen, yuav tsis muaj lub txaj pw hauv tsev kho mob txaus. Thiab peb twb paub lawm tias cov txiaj ntsig hauv tsev kho mob hauv Africa yog qhov phem dua li lwm lub tebchaws, nws hais. "Yog li nws tuaj yeem ua rau muaj kev tuag ntau dua txawm tias cov tub ntxhais hluas."

Kev hloov pauv cuam tshuam nrog cov tshuaj tiv thaiv

Cov kws tshawb fawb nyuam qhuav pib xav seb vim li cas Delta thiaj li txaus ntshai. Lawv tsom mus rau ib txheej ntawm cuaj qhov kev hloov pauv hauv cov noob uas encodes ib qho protein ntau uas soj ntsuam qhov chaw thiab tso cai rau tus kab mob nkag mus rau tib neeg lub hlwb. Ib qho kev hloov pauv tseem ceeb, hu ua P681R, hloov pauv cov amino acid nyob ib sab ntawm qhov chaw furin cleavage qhov twg tib neeg enzyme cleaves cov protein - ib kauj ruam tseem ceeb uas tso cai rau tus kab mob nkag mus rau tib neeg lub hlwb.

Hauv Alpha hom, qhov kev hloov pauv no tau ua kom muaj txiaj ntsig zoo dua. Raws li ib qho kev tshaj tawm ua ntej thaum lub Tsib Hlis lig, Delta kev hloov pauv ua rau nws yooj yim dua rau furin kom tawg. Cov kws tshawb fawb kwv yees tias qhov no tuaj yeem ua rau muaj kev kis tus kabmob kis mus ntxiv.

Txawm li cas los xij, cov kws tshawb fawb Nyij Pooj uas tsim cov kab mob pseudoviruses nqa tib qhov kev hloov pauv tsis tau lees paub tias muaj kev kis kab mob ntau ntxiv hauv cov chaw kuaj mob, thiab hauv Is Nrias teb, lwm qhov sib txawv ntawm tus kabmob coronavirus nrog tib qhov kev hloov pauv tau ua rau kis tsawg dua li Delta, hais tias evolutionary virologist ntawm University. ntawm Edinburgh, Andrew Rambaut). "Yog li yuav tsum muaj kev cuam tshuam nrog lwm yam hauv genome."

Lwm qhov kev hloov pauv ntawm Delta tuaj yeem pab txo qis kev tiv thaiv kab mob. Ib txhia ntawm lawv hloov N-terminal domain ntawm tus txha nraub qaum (NTD) uas protrudes los ntawm qhov chaw ntawm cov protein. Hauv ib tsab xov xwm tsis ntev los no hauv phau ntawv xov xwm Cell, nws tau tshaj tawm tias ib qho ntawm NTD qhov chaw, hu ua "super-site", invariably lub hom phiaj "super-potent" neutralizing antibodies los ntawm cov neeg mob zoo. Qhov tshwj xeeb Delta kev hloov pauv tshem tawm cov amino acids ntawm txoj haujlwm 156 thiab 157 ntawm "superfrequency" thiab hloov cov amino acid 158 los ntawm arginine mus rau glycine - tom kawg tshem tawm qhov chaw sib cuag ncaj qha rau cov tshuaj tiv thaiv kab mob, piav qhia University of Florida tus kws kho mob biologist David Ostrov.

"Peb ntseeg tias qhov kev hloov pauv ntawm 157/158 yog ib qho ntawm qhov txawv ntawm Delta kev hloov pauv uas tau muab cov kab mob no tiv thaiv kev tiv thaiv phenotype," pom zoo Trevor Bedford, kws kho tsiaj hauv computer ntawm Fred Hutchinson Cancer Research Center.

Lwm qhov kev hloov pauv hauv NTD lub cheeb tsam super tuaj yeem tawm tsam cov tshuaj tiv thaiv. Thiab cov kws tshawb fawb yuav tsum pib kawm txog lub luag haujlwm ntawm kev hloov pauv hauv lwm cov Delta proteins, hais tias Nevan Krogan, tus kws tshawb fawb molecular ntawm University of California, San Francisco. “Muaj ntau yam peb tsis paub txog cov kev xaiv no ntawm txhua qib. Peb zoo li yuav taug kev hauv qhov tsaus ntuj. " Piv txwv li, "Delta" muaj ntau qhov kev hloov pauv hauv cov protein nucleocapsid, uas ua haujlwm ntau "zoo li Swiss riam phom," piav qhia txog tus kab mob virologist David Bauer ntawm lub koom haum Francis Crick. Txawm li cas los xij, nws yuav siv sij hawm ntau lub hlis los sim kom paub meej.

Kev txhaj tshuaj sai sai

Lub caij no, cov kws tshawb fawb pom zoo: yuav tsum tau ua sai sai kom tsis txhob kis tus kab mob tshiab. "Kev txhawj xeeb ntawm Delta yuav tsum txhawb peb kom ceev cov tshuaj tiv thaiv thiab ua kom muaj cov tshuaj tiv thaiv nyob rau hauv qhov chaw uas Delta tau txais kev sib tw," said virologist Angela Rasmussen ntawm University of Saskatchewan. Tsoomfwv Meskas Tus Thawj Kav Tebchaws Joe Biden tau thov kom cov neeg Amelikas tau txais tshuaj tiv thaiv tag nrho los tiv thaiv lawv tus kheej los ntawm Delta. Ammon hnub no tau hu rau cov tebchaws nyob sab Europe kom nrawm cov phiaj xwm txhawm rau txhaj tshuaj tiv thaiv cov neeg tsis muaj zog.

Tsis tas li ntawd, nws tau hais tias, yuav tsum tswj hwm kev txwv kom tsis txhob kis tus kabmob tshiab thiab ua rau muaj kev kis tus kabmob tshiab, mus pw hauv tsev kho mob thiab tuag. Cov teb chaws uas txwv tsis pub nkag mus rau cov tshuaj tiv thaiv yuav tsum rov qab mus rau kev ntsuas xws li kev nyob deb ntawm lub cev thiab lub qhov ncauj qhov ntswg, Rasmussen tau hais. Thiab nyob rau hauv Tebchaws Europe, Ammon tau hais kom cov tebchaws ua ob qho tib si: tswj kev txwv thaum ua haujlwm kom txhaj tshuaj tiv thaiv cov neeg tsis muaj zog.

Lub hom phiaj tsis yog tsuas yog cawm neeg txoj sia xwb, tab sis tiv thaiv kev txhim kho ntxiv ntawm tus kab mob. Kev sib kis ntawm Delta tau qhia tias cov kws tshawb fawb tsis muaj peev xwm paub txog cov kev hloov pauv tshiab txaus ntshai nyob rau lub sijhawm los nres lawv txoj kev sib kis, hais tias Emma Hodcroft, tus kws paub txog kab mob hauv University of Basel, txawm hais tias tsis tau muaj lub ntiaj teb kev siv zog los taug qab lawv cov kev hloov pauv hauv lub sijhawm. Nws yuav txaus ntshai xav tias SARS-CoV-2 yuav tsum nres, Katsurakis tau hais. "Txhua yam hauv evolution uas tau tshwm sim tsawg kawg yog ob zaug twb yog tus qauv," nws hais. "Kuv yuav tsis xav tsis thoob yog tias peb pom cov kev hloov pauv zoo sib xws hauv xyoo tom ntej lossis ob xyoos."