COVID-19 Vaccine Update

Content Contributor


COVID-19 continues to devastate our world and thankfully promising vaccines are being developed. With so much talk about these vaccines over the recent months, the discussion below will review some key steps in the production of vaccines, the purpose of vaccines, and comparison of the two vaccines nearing widespread distribution against SARS-CoV-2.  Every day new developments are being made and thus the information in this article may evolve.  However, we will do our best to provide useful information to keep our readers informed in order to allow informed decisions to be made.

Clinical Trials

Clinical trials are research studies that are conducted on people to evaluate a particular medical or surgical intervention.  Clinical trials allow researchers the ability to assess the benefit or harm such interventions cause in their study participants.  Clinical trials initially begin with animal testing.  Once this testing proves favorable the FDA grants permission for the research to move forward with human testing.

Once the FDA grants approval for the trial to begin, the researchers go through three phases.  Phases answer the question of is the intervention safe and effective – does it cause harm and does it work.  Phase I involves a small cohort of people who are treated to evaluate safety.  Phase II involves more study participants and it is used to assess the effectiveness of the treatment.  Finally, in Phase III the treatment is expanded to involve a diverse demographic and varying formulations and dosages of the drug to once again judge for its safety and effectiveness.  After all phases have been completed and results are favorable, the FDA grants approval.


The purpose of a vaccine is to cause the body to create antibodies to fight against a particular virus.  When a person is exposed to a virus, illness can occur if the person does not have a protective defense system of antibodies to fight it off.  The vaccines in discussion prepare the immune system to fight off infection and illness from SARS-CoV-2.  Unlike other vaccines that are made from an inactive or weakened form of the virus, the vaccines from both Pfizer and NIH Moderna are unique in that they are made from messenger ribonucleic acid (mRNA).  This allowed for more rapid development and potentially a safer vaccine.

Protein development

All genetic information is stored in DNA. Everyone has their own, unique genetic code and this code is the start of protein development.  DNA stored in a cell’s nucleus is transcribed into RNA.  RNA needs to travel to a different part of the cell, the cytoplasm, and this is done in the form of messenger RNA (mRNA). Within the cytoplasm are ribosomes. They are responsible for protein production. Ribosomes translate the message from mRNA and make the desired protein.

The instruction from mRNA may be to create proteins that dictate hair color, Alzheimer’s disease, diabetes, or food allergies.  In the case of the mRNA SARS-CoV-2 vaccine, after it is injected, the mRNA enters the cell’s cytoplasm.  mRNA carries the genetic code for the spike protein, a key player in how SARS-CoV-2 enters cells to cause infection. It presents this code to ribosomes that go on to manufacture the coronavirus spike protein.  The spike protein being unfamiliar to the body will trigger the formation of antibodies.  

Once that cell is rechallenged with the spike protein during a real exposure the defense mechanism will be in place and ready to fight so that illness against SARS-CoV-2 will be prevented.  Just imagine soldiers lined up and ready to attack in the event of an enemy invasion.  The soldiers represent the antibodies and the enemy represents the virus.

Vaccine Comparison




NIH Moderna vaccine

Janssen COVID-19 Vaccine

Name of Drug



JNJ 784367735




Adenovirus vector

Start of Phase 3 Trial

July 27, 2020

July 27, 2020

September 23, 2020

Number of Participants Enrolled

43,661over 18 years old

30,000 over 18 years old

43,783 over the age of 18 years old

Study Diversity of United States Participants

Asian 5.5%

Black 10.1%

Hispanic 13.1%

Native American 1.0%

Age 56-85 45.4%

Asian 4%

Black 10%

Hispanic 20%

Age >65 25%

Asian 6%

Black 13%

Hispanic 15%

Native American 1%

Age >60 34%

Study Location

150 clinical trial sites, 6 countries, and 39 US states

100 clinical trial sites in the United States

8 countries including United States, *South Africa and countries within Latin America


Day 1 and day 22

100mcg on day 1 and day 29

IM deltoid

One single dose

Effectiveness against COVID-19

(note: average effectiveness of the flu vaccine is 40%)

95% starting 28 days after first dose, 7 days after second dose

94.5% 14 days after second dose

Overall 66% against moderate to severe disease and 85% against severe disease 28 days after single dose

COVID-19 cases

170 total

162 in *placebo group

8 in vaccine group

95 total

90 in placebo group

5 in vaccine group


Severe COVID-19 cases

10 total

9 in placebo group

1 in vaccine group

11 total

11 in placebo group

0 in vaccine group


Common side effects

Fatigue, headache

Fatigue, muscle aches, pain at injection site



Allergy to polyethylene glycol

Allergy to polyethylene glycol

No anaphylaxis was observed

Data collection

Will continue until 2 years after second dose

Will continue until 2 years after second dose

Will continue until 2 years after single dose


50 million by the end of 2020

1.3 billion by the end of 2021

20 million by the end of 2020 and 500 million to 1 billion doses by the end of 2021



-70 degrees C +/- 10 degrees

and stored in the fridge for 5 days

-20 degrees C and potent for 30 days in refrigerator temperatures

(25 degrees F)

2-8 degrees C and can be stored in the fridge for up to 3 months





*Placebo: a substance that has no therapeutic effect, used as a control in testing new drugs ie saline

*95% of cases in South Africa are the B.1.351 SARS-COV-2 variant where the Jassen vaccine was proven to be 57% effective.

*Recipients with allergies requiring the use of an epi pen are able to receive the vaccines but are advised to receive their vaccine at a specialized center equipped to address possible allergic reactions.

Unanswered Questions

Due to the early stages of vaccine development, many questions such as the ones below will remain unanswered for quite some time.  Participants are still completing Phase III and after following the participants for 2 years more data will be analyzed.  The hope is that as time goes on more will be revealed and the vaccines will continue to prove promising.


  • What are the long term side effects of the vaccine?
  • What is the transmissibility data? Can a person that receives the vaccine transmit the virus if they become infected?
  • What is the length of immunogenicity? How long will the vaccine confer protection?
  • Do people who have been infected with COVID-19 need to get vaccinated?

Other vaccines on the horizon

Astra Zeneca and University of Oxford

ChAdOx1 nCoV-19 vaccine (AZD1222) is a chimpanzee adenovirus vector vaccine which is an engineered virus that delivers genetic instructions to human cells to make the spike protein. There are 20,000 participants who began the study Spring 2020 and they either received two standard doses of the vaccine or a low dose followed by the standard dose.  In contrast to the storage requirements of the Pfizer and Moderna vaccines, AZD1222 can be stored at refrigerator temperatures for 6 months.  This is very appealing to low and middle-income countries that would struggle with vaccinations that need to be kept at very low temperatures.  It is expected to be sold for a few dollars without profit.


NVX-CoV2373 is a version of the virus’ spike protein, known as a protein subunit.   It’s Phase 3 trial started late December 2020. This particular vaccine’s lipid particle consists of an immune boosting compound saponin that is derived from plants.  Other vaccines use the polymer polyethylene glycol that may be associated with the reported allergic reactions with the Pfizer and Moderna vaccines.

Bookmark this page as we will update it when new information is available.

More COVID-19 Information

Viral Testing

COVID-19 Treatments

In addition to the development of vaccines to prevent COVID-19, research is ongoing to create a medication to treat this illness. Remdesivir is one such treatment. On May 1, 2020 it was issued an Emergency Use Authorization (EUA) by the Food and Drug Administration to treat adults and children with COVID-19.

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