Therapeutics

• Author: Dumbrava, Costica
• Pages: 7-12

Lifting coronavirus restrictions

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3.Therapeutics

3.1.Vaccines

A vaccine is key to tackling theCovid-19pandemic, as it wouldprovide healthy peoplewith

immunity from infection (though it wouldnot cure the disease in infected people). The virus that

causes Covid-19 is roughly 80% identical33tothosethatcaused the outbreaks ofSARS and MERS,

whichmay give researchers a good headstart in developing therapeutics. However, earlyevidence

suggestingthat the virus may beunlikely to mutatesignificantly,34making it an easier target, has

been challenged.35Moreover, thedevelopment of a vaccine faces a number ofgreat challenges,

such as not having sufficientknowledgeofthe virus (knowledge gaps), the need to complete

adequate testing of vaccines to ensure safety and, once a vaccine proves effective, making sure that

there isa sufficient amountof it to enableits swift and fairdistributionacross the world.

3.1.1.How do vaccines work?

When a virus enters thebody, it seeks to take control of cells in order to replicate and spread

throughout the body. Generally, vaccines work by exposingthe body to an antigen that will provoke

an immune response, which will then block or kill the virus when the vaccinated person becomes

infected.36Vaccination takes advantage of thebody's immunological memory, which allows it to

'memorise' the specific features of a virus in order to recognise and fight it later in life (adaptive

immunity).37It must be noted that vaccines do not always provide full protectionagainst the viruses

they target, nordo theyalways eliminate the risk of spreadingsuch viruses.38For example, influenza

vaccines mainly reduce the risk of contracting the diseaseand the likelihood of experiencing severe

symptoms.

There are

a number oftypesof vaccines

39

targeting Covid-19 that are currently in development:

vaccines using the virus itself, in aweakenedorinactivatedform (similar to measles and polio

vaccines); viral-vector vaccines, which use other weakenedand genetically engineeredviruses to

prompt the body to produce coronavirus proteins; nucleic-acid vaccines, which use genetic

instructions (in the form of DNA or RNA) for a coronavirus protein to prompt an immune response;

and protein based vaccines that inject harmless elements of coronavirus proteins (particles or shells)

directly into the body to mimic the virus and trigger immune response.

Vaccine candidates are typically tested in several phases, allowingfor thegradual expansion ofthe

number of trial participants from a few dozen (phase 1) to thousands (phase 3). Advancement to

subsequent phases requires specific evidence-based approvals.

33S. Weston and M. B. Frieman, 'COVID-19: knowns, unknowns, and questions',

mSphere

, 2020.

34J. Corum and C. Zimmer, 'How Coronavirus Mutates and Spreads',

New York Times

, 30 April 2020.

35B. Carey and J. Glanz, 'Mutation Allows Coronavirus to Infect More Cells, Study Finds. Scientists Urge Caution',

NewYorkTimes

, 12 June 2020.

36E. Callaway, 'The race for coronavirus vaccines: a graphical guide',

Nature

, 28 April 20202.

37A. Rothstein, 'Vaccines and Their Critics, Then and Now',

The New Atlantis

, No. 44, 2015.

38H. Branswell, 'The world needs Covid-19 vaccines. It may also be overestimating their power',

STAT

, 22 May 2020.

39Callaway, (The race for coronavirus vaccines: a graphical guide) see footnote 35 (above).