Update on the Moderna and Pfizer COVID Vaccines


On Monday, November 16th, Moderna Therapeutics announced that their mRNA-based vaccine achieved 95 percent protection in a field trial comparing 1,500 vaccinated subjects and 1,500 controls receiving a placebo.  Among the trial group, five participants developed COVID-19, all with mild cases.  In contrast, among the non-vaccinated controls, 90 cases were diagnosed with 11 developing severe symptoms. There were no adverse effects associated with vaccination other than transient mild body ache, fatigue and headache in a small proportion of recipients following the second vaccination.


Based on the trial, Moderna has submitted data to the U.S. Food and Drug Administration for emergency use authorization. Dr. Tal Zachs, Chief Medical Officer of Moderna, stated “It was one of the greatest moments in my life and my career.  It is absolutely amazing to be able to develop this vaccine and see the ability to prevent symptomatic disease with such high efficiency.”

Dr. Anthony Faucci

Director NIAID-NIH


Dr. Antony Fauci, Director of the National Arthritis and Infectious Diseases Center of the National Institute of Health, stated “These are obviously very exciting results.  It’s just as good as it gets.”  Dr. Fauci predicts that the first vaccinations will commence towards the end of December, subject to approval, but restraints on production will restrict general administration until April.


Similar efficacy was documented for the Pfizer-BioNTech vaccine developed without U.S. Federal funding, although the DHHS has committed to purchasing 100 million doses. The Pfizer-BioNTech vaccinates demonstrated eight cases, with one seriously affected. In contrast among the placebo group there were 162 cases with eleven assessed as clinically severe. This vaccine was 94 percent effective in recipients over 65 years old, regarded as a demographic at high risk of complications from COVID infection.


Both the Moderna and the previously announced Pfizer vaccine deliver mRNA, coding for specific antigenic spike protein carried by the coronavirus.  The immune system of the recipient generates antibodies to the spike protein providing immunity.  At this stage, the duration of protective immunity is unknown but this will become apparent in coming months following wide distribution of the vaccine. 


The difference between the Moderna and Pfizer vaccine is that the former product is stable for up to six months held at -100 F, but may be stored in a conventional refrigerator for up to 30 days and 12 hours at room temperature without losing immunogenicity.  This property will facilitate distribution and administration. The Pfizer vaccine requires a critical cold chain of -100 F that will represent restraints in distribution and storage to the point of administration.


The Moderna vaccine program calls for an initial vaccination followed by a booster dose 21 days later.  There is a suggested 28 day period between the first Pfizer vaccination and the booster.


The need for a vaccine is becoming more urgent given the ascending incidence rate across virtually the entire nation. As of November 17th the U.S. has recorded 11.4 million diagnosed cases of COVID with 250,000 fatalities. Over the past seven days 1.1 millon cases were diagnosed. In contrast it required 96 days from the emergence of Covid to attain the first million cases. Unfortunately the initial availability of vaccine will require restriction to a priority list through the first quarter of 2021. Thereafter greater quantities of vaccine will be available subject to manufacturing and logistic restraints.


Following approval of the two vaccines and possibly other candidates by the FDA it will be necessary to initiate a campaign to encourage our population to accept the benefits of vaccination and overcome reluctance based on prevailling fear and uncertainty. This has been fuelled by conflicting messages from responsible medical professionals, epidemiologists contrasted with unscientific and irresponsible statements by politicians. The quicker we control COVID the more rapidly we can restore our economy and our previous way of life.