COVID-19 UPDATE
COVID-19 Vaccination Overview: From the Beginning to Present By Alan M. Preston, MHA, ScD
The virus that causes COVID-19 is related to other coronaviruses. The good news is that scientists have been studying coronaviruses for years and there is a lot we have learned. Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) are not new, and vaccinations have been developed for previous strains. Nevertheless, each strain requires a specific vaccine to combat the RNA makeup of such strain in order to be an effective vaccine. Currently, there are three approved vaccines: 1. Pfizer-BioNTech: for ages 12 years and older and needs 2 shots given 3 weeks (21 days) apart. 2. Moderna: for ages 18 years and older and needs 2 shots given 4 weeks (28 days) apart. 3. Johnson & Johnson’s Janssen: for ages 18 years and older and needs 1 shot. Vaccines go through three phases of clinical trials to make sure they are safe and effective. For other vaccines routinely used in the United States, the three phases of clinical trials are performed one at a time and do not overlap, which is why the standard process is so lengthy. The third phase usually takes the longest. During the development of COVID-19 vaccines, these phases have overlapped to speed up the process. No trial
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phases have been skipped. These three preliminary clinical trials must be performed to obtain approval from the FDA:
the candidate vaccine and determine the type and extent of immune response that the vaccine provokes.
1. Phase I Vaccine Trials This first trial involves a small group of adults, usually between 20-80 subjects. If the vaccine is intended for children, researchers will first test adults and then gradually step down the age of the test subjects until they reach their target. This is one reason that the age limits for children are in place. The goals of Phase 1 testing are to assess the safety of
2. Phase II Vaccine Trials A larger group of several hundred individuals participates in Phase II testing. Phase II testing aims to study the individual vaccine’s safety, efficacy, proposed doses, schedule of immunizations and delivery method. 3. Phase III Vaccine Trials Successful Phase II candidate vaccines
