It belongs to the family of coronaviruses,

named for crownlike spikes

on their surfaces.

SARS CoV-2 can cause COVID-19,

a contagious viral infection

that attacks primarily your throat and lungs.

What actually happens in your body

when you contract the coronavirus?

What exactly causes your body

to develop pneumonia?

And how would a vaccine work?

The coronavirus must infect living cells

in order to reproduce.

Let's have a closer look.

Inside the virus,

genetic material contains the information

to make more copies of itself.

A protein shell provides a hard protective

enclosure for the genetic material

as the virus travels between

the people it infects.

An outer envelope allows the virus

to infect cells by merging with

the cell's outer membrane.

Projecting from the envelope are

spikes of protein molecules.

Both a typical influenza virus and

the new coronavirus use their spikes

like a key to get inside a cell in your body,

where it takes over its internal machinery,

repurposing it to build the components

of new viruses.

When an infected person talks,

coughs or sneezes,

droplets carrying the virus may land

in your mouth or nose

and then move into your lungs.

Once inside your body,

the virus comes into contact

with cells in your throat, nose or lungs.

One spike on the virus

inserts into a receptor molecule

on your healthy cell membrane

like a key in a lock.

This action allows the virus

to get inside your cell.

A typical flu virus would travel

inside a sack

made from your cell membrane

to your cell's nucleus

that where your cell houses

all its genetic material.

The coronavirus, on the other hand,

doesn't need to enter the host cell nucleus.

It can directly access parts of the host cell,

called Ribosomes.

Ribosomes use genetic information

from the virus to make viral proteins,

such as the spikes on the virus' surface.

A packaging structure in your cell

then carries the spikes in vesicles,

which merge with your cell's

outer layer, the cell membrane.

All the parts needed to create a new virus

gather just beneath your cell's membrane.

Then a new virus begins to butt off

from the cell's membrane.

For this, we'll have to look into your lungs.

Each lung has separate sections,

called lobes.

Normally, as you breathe, air moves freely

through your trachea, or windpipe,

then through large tubes, called bronchi,

through smaller tubes, called bronchioles,

and finally into tiny sacs, called alveoli.

Your airways and alveoli

are flexible and springy.

When you breathe in,

each air sac inflates like a small balloon.

And when you exhale, the sacs deflate.

Small blood vessels, called capillaries,

surround your alveoli.

Oxygen from the air you breathe

passes into your capillaries,

then carbon dioxide from your body

passes out of your capillaries

into your alveoli so that your lungs

can get rid of it when you exhale.

Your airways catch most germs

in the mucus that lines your trachea,

bronchi, and bronchioles.

In a healthy body,

hair-like cilia lining the tubes

constantly push the mucus and germs

out of your airways,

where you may expel them by coughing.

Normally, cells of your immune system

attack viruses and germs that

make it past your mucus and cilia

and enter your alveoli.

However,

if your immune system is weakened

like in the case of a coronavirus infection,

the virus can overwhelm your immune cells

and your bronchioles and alveoli

become inflamed

your immune system attacks

the multiplying viruses.

The inflammation can cause

your alveoli to fill with fluid,

making it difficult for your body

to get the oxygen it needs.

You could develop lobar pneumonia,

where one lobe of your lungs is affected,

or you could have bronchopneumonia

that affects many areas of both lungs.

Pneumonia may cause...

difficulty breathing

chest pain

coughing

fever and chills

confusion

headache

muscle pain

and fatigue.

It can also lead to

more serious complications:

respiratory failure occurs when

your breathing becomes so difficult

that you need a machine called

a ventilator to help you breathe.

These are the machines that save lives

and medical device companies currently

ramp up production for.

Whether you would develop

these symptoms depends on

a lot of factors, such as

your age and whether you

already have an existing condition.

While all this all sounds scary,

the push to develop a coronavirus vaccine

is moving at high speed.

Studies of other coronaviruses

lead most researchers to assume that

people who have recovered from

a SARS-CoV-2 infection could be protected

from reinfection for a period of time.

But that assumption needs to be backed

by empirical evidence and

some studies suggest otherwise.

There are several different approaches

for a potential vaccine

against the coronavirus.

The basic idea is that

you would get a shot that contains

faint versions of the virus.

The vaccine would expose your body

to the virus that is too weak

to cause infection but just strong enough

to stimulate an immune response.

Within a few weeks,

cells in your immune system would

make markers called antibodies,

which would be specific for

only the coronavirus or specifically

its spike protein.

Antibodies then attach to the virus and

prevent it from attaching to your cells.

Your immune system then responds

to signals from the antibodies

by consuming and destroying

the clumps of viruses.

If you then catch the real virus

at a later stage,

your body would recognize and destroy it.

In other words,

your immune system is now primed.

Collecting evidence on

whether this will be possible,

safe and effective

is part of what's taking researchers

so long to develop a vaccine.

It is a race against time

to develop a vaccine amid a pandemic.

Each step in vaccine development

usually takes months if not years.

An Ebola vaccine broke records

by being ready in five years.

The hope here is

to develop one for the new coronavirus

in a record-breaking 12 to 18 months.

While all this will take time,

stay home if you can

to protect the most vulnerable

and don't forget to wash your hands

for at least 20 seconds and

as often as possible.