What is a coronavirus? - Elizabeth Cox

Prevodilac: Aleksandar Bošnjak Lektor: Milenka Okuka

For almost a decade, scientists chased the source of a deadly new virus

Skoro jednu deceniju naučnici su tragali za izvorom novog smrtonosnog virusa

through China’s tallest mountains and most isolated caverns.

kroz najviše planine u Kini i najizolovanije pećine.

They finally found it here: in the bats of Shitou Cave.

Najzad su ga našli u šišmišima u pećini Šitau.

The virus in question was a coronavirus

Virus o kome je reč je koronavirus

that caused an epidemic of severe acute respiratory syndrome,

koji je izazvao epidemiju teškog akutnog respiratornog sindroma,

or SARS, in 2003.

ili SARS-a, 2003. godine.

Coronaviruses are a group of viruses

Koronavirusi su grupa virusa

covered in little protein spikes that look like a crown—

koji su pokriveni malim proteinskim šiljcima

koji izgledaju kao krune, ili "corona" na latinskom.

or "corona" in Latin.

There are hundreds of known coronaviruses.

Postoji stotine poznatih koronavirusa.

Seven of them infect humans, and can cause disease.

Njih sedam može da zarazi čoveka i izazove bolest.

The coronavirus SARS-CoV causes SARS, MERS-CoV causes MERS,

Koronavirus SARS-CoV uzrokuje SARS, MERS-CoV uzrokuje MERS,

and SARS-CoV-2 causes the disease COVID-19.

a SARS-CoV-2 uzrokuje bolest COVID-19.

Of the seven human coronaviruses, four cause colds,

Od sedam ljudskih koronavirusa, četiri izazivaju prehlade,

mild, highly contagious infections of the nose and throat.

srednje i jako zarazne infekcije nosa i grla.

Two infect the lungs, and cause much more severe illnesses.

Dva inficiraju pluća, i uzrokuju mnogo teža oboljenja.

The seventh, which causes COVID-19, has features of each:

Sedmi, koji uzrokuje COVID-19, ima karakteristike svih koronavirusa:

it spreads easily, but can severely impact the lungs.

lako se širi, ali može ozbiljno da utiče na pluća.

When an infected person coughs, droplets containing the virus spray out.

Kada zaražena osoba kašlje, kapljice koje sadrže virus se šire.

The virus can infect a new person when the droplets enter their nose or mouth.

Virus može da inficira novu osobu kad kapljice uđu u njihov nos ili usta.

Coronaviruses transmit best in enclosed spaces,

Koronavirus se prenosi najbolje u zatvorenim prostorima,

where people are close together.

kada su ljudi blizu jedni drugih.

Cold weather keeps their delicate casing from drying out,

Hladno vreme održava njihove delikatne omotače vlažnim,

enabling the virus to survive for longer between hosts,

omogućavajući virusu da duže preživi između domaćina,

while UV exposure from sunlight may damage it.

dok izlaganje sunčevim UV zracima može da ih ošteti.

These seasonal variations matter more for established viruses.

Varijacije godišnjih doba su bitnije za ustanovljene viruse.

But because no one is yet immune to a new virus,

Ali zbog toga što još niko nije imun na novi virus,

it has so many potential hosts that it doesn’t need ideal conditions to spread.

ima toliko potencijalnih domaćina da mu ne trebaju idealni uslovi.

In the body, the protein spikes embed in the host’s cells and fuse with them—

U telu, proteisnki šiljci se ugrađuju u ćeliju domaćina i spajaju se sa njom,

enabling the virus to hijack the host cell’s machinery

omogućavajući virusu da preuzme kontrolu nad mašinerijom ćelija domaćina

to replicate its own genes.

kako bi replikovao svoje gene.

Coronaviruses store their genes on RNA.

Koronavirus skladišti svoje gene u RNK.

All viruses are either RNA viruses or DNA viruses.

Svi virusi su ili RNK virusi ili DNK virusi.

RNA viruses tend to be smaller, with fewer genes,

RNK virusi su manji i imaju manje gena,

meaning they infect many hosts and replicate quickly in those hosts.

što znači da inficiraju mnogo domaćina i replikuju se brže u njima.

In general, RNA viruses don’t have a proofreading mechanism,

Uopšteno, RNK virusi nemaju mehanizam za proveru,

whereas DNA viruses do.

dok DNK virusi imaju.

So when an RNA virus replicates,

Dakle kad se RNK virus umnožava,

it’s much more likely to have mistakes called mutations.

verovatnije je da sadrži greške koje se zovu mutacije.

Many of these mutations are useless or even harmful.

Mnoge od ovih mutacija su beskorisne ili čak štetne.

But some make the virus better suited for certain environments—

A neke stvaraju virus koji bolje odgovara određenim okruženjima,

like a new host species.

kao na primer novoj vrsti domaćina.

Epidemics often occur when a virus jumps from animals to humans.

Epidemije često nastaju kada virus skoči sa životinje na čoveka.

This is true of the RNA viruses that caused

Ovo je istina za RNK viruse koji su izazvali

the Ebola, Zika, and SARS epidemics, and the COVID-19 pandemic.

ebolu, ziku, epidemiju SARS-a i pandemiju COVID-19.

Once in humans, the virus still mutates—

Jednom kad je u ljudima, virus i dalje mutira,

usually not enough to create a new virus,

ali ne dovoljno da stvori novi virus,

but enough to create variations, or strains, of the original one.

ali dovoljno da stvori varijacije ili sojeve originalnog virusa.

Coronaviruses have a few key differences from most RNA viruses.

Koronavirusi imaju nekoliko ključnih razlika od većine RNK virusa.

They’re some of the largest, meaning they have the most genes.

Oni su jedni od najvećih, što znači da imaju najviše gena,

That creates more opportunity for harmful mutations.

To stvara više prilika za štetne mutacije.

To counteract this risk, coronaviruses have a unique feature:

Kako bi se suprotstavili ovom riziku, koronavirusi imaju jedinstvenu odliku,

an enzyme that checks for replication errors and corrects mistakes.

a to je enzim koji proverava greške replikacija i ispravlja greške.

This makes coronaviruses much more stable,

Zbogo ovoga su koronavirusi mnogo stabilniji,

with a slower mutation rate, than other RNA viruses.

sa sporijom stopom mutacije od drugih RNK virusa.

While this may sound formidable,

Dok ovo može da zvuči strašno,

the slow mutation rate is actually a promising sign

spora stopa mutacija je zapravo povoljna šansa

when it comes to disarming them.

za njihovo razoružavanje.

After an infection, our immune systems can recognize germs

Nakon infekcije, naši imuni sistemi mogu da prepoznaju klice

and destroy them more quickly if they infect us again

i unište ih brže ako nas inficiraju ponovo

so they don’t make us sick.

tako da se ne razbolimo.

Mutacije mogu da stvore viruse

But mutations can make a virus less recognizable to our immune systems—

koji su manje prepoznatljivi našim imunim sistemima,

and therefore more difficult to fight off.

i zbog toga je teže izboriti se sa njima.

They can also make antiviral drugs and vaccines less effective,

Zbog njih su takođe antivirusni lekovi i vakcine manje učinkoviti

because they’re tailored very specifically to a virus.

jer su oni prilagođeni specifično za svaki virus.

That’s why we need a new flu vaccine every year—

Zato nam treba vakcina protiv gripa svake godine,

the influenza virus mutates so quickly that new strains pop up constantly.

Virus gripa mutira toliko brzo da konstantno iskaču novi sojevi.

The slower mutation rate of coronaviruses means

Sporija stopa mutacija koronavirusa znači

our immune systems, drugs, and vaccines

da naši imuni sistemi, lekovi i vakcine

might be able to recognize them for longer after infection,

možda mogu da ih prepoznaju duži period nakon infekcije,

and therefore protect us better.

stoga i da nas bolje štite.

Still, we don’t know how long our bodies remain immune to different coronaviruses.

Ipak, ne znamo koliko dugo naša tela ostaju imuna na različite koronaviruse.

There’s never been an approved treatment or vaccine for a coronavirus.

Nikada nismo imali odobrenu terapiju ili vakcinu za koronavirus.

We haven’t focused on treating the ones that cause colds,

Nismo se fokusirali na lečenje onih koji izazivaju prehlade,

and though scientists began developing treatments for SARS and MERS,

a iako su naučnici započeli razvijanje terapija za SARS i MERS,

the epidemics ended before those treatments completed clinical trials.

epidemije su prestale pre nego što su završene kliničke studije za te terapije.

As we continue to encroach on other animals’ habitats,

Dok mi i dalje zadiremo u druga životnjska staništa,

some scientists say a new coronavirus jumping to humans is inevitable—

neki naučnici kažu da je skakanje novog koronavirusa na čoveka neizbežno,

but if we investigate these unknowns, it doesn’t have to be devastating.

ali ako istražimo ove nepoznate stvari, ne moraju da budu pogubne.