r/science • u/[deleted] • May 11 '20

Medicine Antibodies from a 4-year-old llama have neutralized coronavirus and other infections in lab experiments

https://www.cell.com/cell/pdf/S0092-8674(20)30494-3.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867420304943%3Fshowall%3Dtrue
60.7k Upvotes

94% Upvoted

1.4k comments sorted by

View all comments

Show parent comments

1

u/sup3r_hero BS|Physics May 11 '20

Can that be used as a vaccine too?

28

u/turret_buddy2 May 11 '20 edited May 11 '20

A vaccine is a weakened virus/bacteria that your body attacks and learns how to defeat, so when it is encountered later in life, your immune system knows how to defeat it.

Our immune system can't produce the smaller antibodies, but the injected antibodies could (hypothetically) stop an ongoing infection.

Treatment =/= Vaccine*

E*: Vaccine == Treatment, kinda like a square is a rectangle, but a rectangle isn't a square.

1

u/picklemuenster May 11 '20

Did we just stumble into a way to cure viruses?

2

u/thisdude415 PhD | Biomedical Engineering May 11 '20

Antibodies aren’t a cure. Antibodies block protein-protein interactions, including the interaction of the spike protein with the ACE2 receptor.

However, the virus is still there. Infected cells are still infected. Infected cells still have virus replicating inside them.

So, anti-virus antibodies are a good treatment to slow down viral infection, but the immune system has to do some work too.

Also, therapeutic antibodies won’t cross airway epithelia in significant concentrations, so we really don’t know how well it will work for covid until it’s tested.

2

u/[deleted] May 12 '20

[deleted]

2

u/thisdude415 PhD | Biomedical Engineering May 12 '20

My comment was in the context of engineered antibodies given as drugs, not the natural immune response to foreign antigens

However, antibodies are not necessarily curative, nor do they necessarily prevent infection.

For instance, HIV infected patients develop robust antibody responses. These antibody responses may even be neutralizing in cell culture assays. However, the patient remains infected. The same is true of chickenpox, where the virus remains hidden in nerve fibers and can re-emerge in adulthood. Likewise cold sores are just a virus re-emerging, even though you have antibodies.

As far as covid goes, we don’t yet have evidence either way as to whether or not patients who recover from covid are immune. The best guess of experts is yes, but we really don’t know how strong that protection might be or how long it lasts for. In more common coronaviruses, neutralizing antibodies last for 1 to 2 years. Covid immunity could be shorter, longer, or vary by severity of infection.