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polymerase (RdRP) enzyme, a crucial component in RNA replication [step 3]. Seemingly effective,
remdesivir needs more large-scale testing. The Japanese influenza antiviral favipiravir, marketed under
the brand name Avigan, is thought to have a similar mode of action. After administering clinical trials
of 340 patients, a Chinese official gave encouraging feedback that favipiravir was “clearly effective” in
treating the coronavirus (The Guardian). Likewise, protease inhibitors, another class of antivirals, block
the activity of enzymes that catalyze the breakdown of proteins [step 2]. The protease inhibitors lopina-
vir and ritonavir are combined into a fixed-dose anti-HIV medication, sold under the brand name
Kaletra. For serious COVID-19 cases, however, a Chinese study of 199 patients concludes, “[N]o benefit
was observed with lopinavir-ritonavir treatment beyond standard care” (The New England Journal of
Medicine).

Other drugs utilize an alternative approach: blocking the virus from interacting with its host cells. Re-
searchers have identified several human proteins which the virus needs to function properly; they’re
trying to find drugs that bind to those proteins. Since these drugs target us, not the virus, they’re still
usable even if the virus mutates—a significant advantage over the previous method. For instance, the
antimalarial chloroquine and its derivative hydroxychloroquine raise the pH of the intracellular en-
vironment, hindering the virus’s entry into the cell [step 1] and its activity within the cell [steps 2-5].
The two drugs have garnered a lot of media attention, with President Donald Trump claiming that
hydroxychloroquine taken with the antibiotic6 azithromycin could be “one of the biggest game chang-
ers in the history of medicine” (Twitter) and Elon Musk remarking that chloroquine might be “worth
considering” (Twitter). Furthermore, an agent called camostat mesylate may be helpful as it impedes the
protease TMPRSS2, required for the virus to enter the cell [step 1]. A potential problem is that multiple
proteases are performing the same role. At the moment, studies for these medicines are inconclusive or
have contradictory findings. More trials are necessary to determine their effectiveness.

Some medications do not affect the viral life cycle, but instead help dampen the body’s immune inflam-
matory response [step 8], which will reduce the damage done to the lungs. Convalescent plasma, the
liquid component of blood from recovered COVID-19 patients, is under investigation. The survivors/
donors have developed antibodies, proteins that recognize and bind to viral antigens (structures that
stimulate the immune response), defending the body from the foreign invasion. Plasma transfusions
establish passive immunity within the infected patients, which may help alleviate their symptoms. Be-
sides convalescent plasma, there are also monoclonal antibodies, synthetic proteins that act like human
antibodies; they’re identical copies of one type of antibody, and hence “monoclonal”. An example of
this would be the immunosuppressant tocilizumab. So far, the drug appears to be effective with a small
sample of patients (Cancer Network).

Counterattack II: Vaccinations
Recovery alone is insufficient. A safe, healthy person today may fall victim to the virus tomorrow. If we
want SARS-CoV-2 to be eradicated, vaccination is our best hope.

Vaccines train the body’s immune system to combat pathogens by introducing information that induc-
es the production of antibodies. If you’ve encountered the pathogen before, then your body will know
how to deal with it because of the antibodies. This is called immunological memory, and it’s why after
getting vaccinated, your immune system can quickly identify the threats and initiate an appropriate
counterattack.

A typical vaccine contains antigens of a pathogen that are injected into the body without causing symp-
toms of the disease, though mild side effects may still occur. There are four main types of vaccines. Live,
attenuated vaccines use weakened pathogens, while inactivated vaccines use microbes that have been
killed. Toxoids are inactivated toxins from the pathogen, and subunit vaccines are composed of anti-
genic fragments of the pathogen.

The global coronavirus vaccine race has been going on since the beginning of 2020. The international
scientific community is cooperating, and vaccines are expected to enter the market in about 12-18

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