Have you ever heard of an antibody cocktail?
Although you might be picturing this... [an image of an actual cocktail drink]
An antibody cocktail is actually a mixture of proteins that defend our body against various
harmful diseases.
Similar to a bartender that mixes several ingredients
to make different cocktails, scientists can
mix various antibodies to make treatments for different viruses.
Scientists have actually curated promising antibody
mixtures to target the new coronavirus that causes COVID-19.
One of these treatment cocktails is called Regen-Cov, which was created by Regeneron
Pharmaceuticals.
This treatment is composed of casirivimab and imdevimab antibodies that are specifically
related to fighting SARS-CoV-2.
These molecules are made in the lab, based on human and mice immune systems.
Together they are administered to a patient through an IV infusion or a shot.
But how does the treatment work?
The way the immune system works is similar to a battlefield.
The body studies the enemy and then creates soldiers to fight against the intruders.
In this case, the enemy is the coronavirus variants.
The antibodies are the soldiers. The body deploys these specific soldiers, casirivimab
and imdevimab, which can attack the spike protein on the virus.
When our bodies are introduced to new pathogens, or invaders, they begin to create antibodies
to defend themselves.
This is why people who have gotten sick before or who were introduced to a virus through a vaccine
are better adept at fighting against that virus.
This treatment is designed to help naïve patients,
or patients who do not yet have this protection.
While the theory behind monoclonal antibody treatment is logical,
the question remains: is this treatment actually effective in humans?
To test this, several clinical trial studies have been conducted.
One such study tested the effectiveness of the Regeneron antibody treatment in about
2500 people,
including high risk individuals.
Every person in the study was initially uninfected but living with an infected person for about
a month.
Half the participants received the treatment and the other half received a placebo.
So… what were the results?
Monoclonal antibody treatment resulted in a lower risk of infection, lower risk of showing
symptoms, less time being sick with said symptoms, and less time being highly contagious by about
1 week on average.
Overall, the treatment proved to be effective in preventing more infection and mitigating
symptoms.
But what about preventing severe disease outcomes such as hospitalization and death in those
already infected?
Another study found that the monoclonal antibody treatment led to a decrease in the risk of
death, risk of needing a ventilator, and a decrease in the number
of days spent at the hospital.
This effect was seen in people with no previous exposure to the virus, either naturally through
previous infection
or by receiving a vaccine.
However, this effect was not observed in people with some immunity already developed.
Although this treatment is promising, it's clear that there are some limitations to when
and how it can be used.
Based on the results of these and other clinical studies,
the FDA approved the Regen-Cov treatment for
individuals that are at a high risk of hospitalization or death.
These individuals must either be not fully vaccinated or immunocompromised.
Immunocompromised individuals are not able to get fully vaccinated or vaccinated at all
due to certain health
conditions or even their medication.
Individuals are able to get this treatment in
two scenarios.
The first case being when the individual is exposed to an infected individual.
The second is when the individual is at a high risk of being exposed to an infected individual.
So for example, prisons or in nursing homes. In all of these cases, however,
the individual must weigh at least 40 kg and be at least 12 years
of age or older.
Although the Regeneron antibody treatment seems promising for treating COVID-19,
there are still some limitations.
This treatment cannot be used in patients that are hospitalized, or in patients that
require oxygen therapy to breathe either due to COVID-19 or another pre-existing condition.
That said, this treatment is useful in preventing severe illness from occurring but not in treating
COVID-19 patients that are already experiencing severe symptoms.
In certain cases, using this treatment may even worsen the illness.
Despite these limitations, there are still clear
instances where monoclonal antibodies are effective.
So then why are they not regularly used in Canada?
There are two main reasons as to why this treatment is not popular here in Canada.
The first is that they are incredibly expensive.
The US has purchased about 3 million doses for around $2100 USD each.
Whereas Canada, with its free but limited healthcare system, has only purchased around
9000 doses.
Even if Canada had a sufficient amount of doses, these monoclonal antibody treatments
need to be administered at infusion centres, which are typically found within hospitals.
Currently, there are not enough of these centres, however, Canada plans to set up more in the
near future.
At the beginning of the pandemic, healthcare professionals weren’t able to do much for
individuals who tested positive for the COVID-19 and didn’t need to be hospitalized.
This meant that they simply let the virus run its course.
If the symptoms became very serious then the individual would be treated with oxygen therapy
and other advanced treatments.
While the monoclonal antibody treatments are able to prevent the progression of symptoms,
it's important to note that these treatments are in no way a substitute for
vaccination.
Individuals who can get vaccinated should do so,
so that their bodies can defend themselves against the virus without needing a $2000 treatment.
Monoclonal antibodies offer a unique solution to complications of COVID-19.
This treatment option can save lives, but it's incredibly time-sensitive.
Healthcare providers must be diligent in knowing when to add this to a patient’s treatment plan,
as proper timing can be the difference between life and death.