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Happy Dance #3

Happy Dance for Pfizer Clinical Trial Results - It was 95% effective!!  There were no serious safety concerns. 

I was awake Wednesday morning when the email from Pfizer arrived in my inbox, just 2 days after Moderna's wonderful preliminary report -  what great news!  The independent Pfizer Data Safety and Monitoring Board (DSMB) broke the blinded study when the number of symptomatic, Covid-19 positive volunteers reached 170 cases.  The number rose quickly from their first look at 94 cases  because of the surge in new cases around the country.  Neither Pfizer, nor the volunteers, knew which group had the positive cases.  The DSMB is a group of scientists and statisticians who are allowed to look at the data at preset intervals.  The results showed that 162 of the infected patients were in the placebo group and 8 were in the vaccinated group, with 9 severe cases in the placebo group and 1 in the vaccinated group (new data since the 1st data review). And 94% of older patients were protected.  Vaccinated patients complained of fatigue and flu-like symptoms, but there were no reported serious adverse effects. 

With these results, Pfizer can now apply for Emergency Use Authorization for the vaccine in order to start vaccinating the placebo group and others.  Health care workers will probably be the 1st group - from the 25  million doses that will come to the US (2 shots per person 21 days apart).   The vaccinated patients will continue to be followed for a full 24 months in order to look for any late adverse effects.  The placebo group will probably be vaccinated as soon as the EUA is received.  Continue reading below.


Pfizer and Moderna vaccines were the first messengerRNA vaccines ever brought to this level, and their effectiveness is very impressive.    This vaccine development platform allowed the mRNA for a portion of the spike protein to be prepared very quickly by Moderna and NIH-National Institute of Allergy and Infections Diseases, with Dr. Tony Fauci as head.  NIH had been studying the coronaviruses for many years, and the spike protein of the virus was known to be the part of the virus which attaches to a receptor on human cells allowing the virus to infect mucosal cells in the nose, trachea and lungs.  

All of the vaccines under development are using techniques to isolate parts of the spike protein and to stimulate the immune system.  There are at least 4 categories of vaccine types, and the mRNA technique is just one of those - the newest.  The messengerRNA (a genetic pattern for a piece of the spike protein)  is prepared and injected into our muscles.  It enters our cells and acts as a template for them to make a small inactive piece of the spike protein.  Our cells then become a factory and as "spike protein" is made, it stimulates an immune response. I find it really fascinating!!

There will be much more information to come from the Pfizer and Moderna studies.  NIH will assess all parts of the immune response in the vaccinated volunteers, which will help scientists to understand the duration of immunity stimulated by the vaccine.  After the FDA receives the EUA application from Pfizer, the scientists appointed to an FDA board will review all of the data and make a decision.  It usually takes weeks for a decision, but the urgency for vaccine approval is such that it may be just a few weeks.  Then distribution can begin.  This will be a topic for another blog post.


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