In this presentation, I talked about the new mRNA vaccine that is authorized for the prevention of coronavirus infection. mRNA 1273 is developed by Moderna in the US and has shown almost 94% effectiveness

1. Serena Z. Hijazeen

2. OUTLINE
Introduction
COVID19
overview
Development
Mechanism of
work
Recap
Serena Z. Hijazeen

3. INTRODUCTION
• Messenger RNA (mRNA) is a single-stranded RNA molecule that carries
messages from the DNA to the cytoplasm where protein are made, based on the
cell’s requirements
• During protein synthesis, an organelle called a ribosome moves along the mRNA,
reads its base sequence, and uses the genetic code to translate each three-base
triplet, or codon, into its corresponding amino acid.
Serena Z. Hijazeen

4. INTRODUCTION
• A mRNA vaccine is a new concept in immunology, this type of vaccine allows
the cells inside the body to make a protein or a piece of a protein that
triggers an immune response which leads to the formation of antibodies
that protects the body in case it got infected by the actual virus.
Serena Z. Hijazeen

5. COVID19 OVERVIEW
• Back in December 2019 in Wuhan, China the virus initiated,
and now after almost a year scientists have collected enough
data for us to understand its structure.
• SARS-CoV-2 entry is mediated by the transmembrane spike
(S) glycoprotein which produces homotrimers protruding
from the viral surface.
• There is 2 subtypes for S protein, S1 which binds to the host
and S2 which facilitate the fusion between the viral and
cellular membranes.
Serena Z. Hijazeen

6. • S trimers are extensively decorated with N-linked glycan that can are important for
proper folding and for modulating accessibility to the host’s protease and neutralizing
antibodies.
• Angiotensin converting enzyme 2 (ACE2) mediates SARS-CoV-2 entry to the cells,
establishing it as a functional receptor for the novel virus.
Serena Z. Hijazeen
COVID19 OVERVIEW

7. The development journey began back in February 2020, it took 25
days from sequence selection to vaccine manufacturing, and
clinical trails were initiated.
In April 27th they submitted for phase II study, and on 27th july
they submitted for phase III which was conducted in a
collaboration with the National Institute of Health.
On 18th December 2020, the FDA issued an emergency use
authorization (EUA) for the vaccine
THE DEVELOPMENT PROCESS
Serena Z. Hijazeen

8. • mRNA 1273 uses a lipid-based nanoparticle carrier system, that prevents the rapid
degradation of mRNA and facilitates its delivery.
• The lipid nanoparticle is stabilized by a polyethylene glycol 2000 lipid conjugate which
provides a hydrophilic layer and prolong the half-life.
Serena Z. Hijazeen
THE DEVELOPMENT PROCESS

9. DOSING
• The vaccine is administrated intramuscularly, in two doses (100mcg/0.5ml) separated
by 28 days (4 weeks apart).
• The vaccine should be administered with no other vaccine (14 days intervals), due to
lack information on the safety.
• Vaccination should be available even for those who got infected with SARS-CoV-2
previously.
• People who are still infected with COVID19 should wait until recovery to get vaccinated.
Serena Z. Hijazeen

10. Serena Z. Hijazeen
• Patients who received passive antibody therapy of COVID19; since they are unlikely to
get re-infected within the next 90 days, they should be vaccinated after 90 days as an
extra precaution until enough information is gathered.
• The vaccine does not work as a post-exposure prophylaxis; since the incubation period
of the virus is 4-5 days, because it is unlikely to develop the acquired immunity from the
first dose.
DOSING

11. Serena Z. Hijazeen
• Some people who received the vaccine has shown anaphylactic reaction, which lead
the FDA to exclude anyone with previous severe acute allergic reaction from a drug or
a vaccine that contains PEG and its derivatives.
• There is no knowledge on how the allergic reaction occurs. It is possible that some
populations are of high risk of non-IgE-mediated mast cell activated, or complement
activation related to either the lipid or the PEG-lipid component of the vaccine.
ALLERGIC REACTIONS

12. REFERENCES
• https://www.genome.gov/genetics-glossary/messenger-rna.
• https://www.sciencedirect.com/science/article/pii/S0092867420302622
• https://www.nejm.org/doi/full/10.1056/NEJMoa2035389
• https://www.modernatx.com/modernas-work-potential-vaccine-against-covid-19
• https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mrna.html
• https://www.nejm.org/doi/full/10.1056/NEJMra2035343?query=recirc_mostViewed_ra
ilB_article
• https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html
Serena Z. Hijazeen

13. Serena Z. Hijazeen