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November 11, 2020

Happy Dance

Why we should be happy and doing a dance?  The Pfizer and Moderna vaccines were made with a completely new process and no one knew whether it would be successful.  Messenger RNA for a portion of the virus spike protein was created and after injection the mRNA entered muscle cells stimulating them to make antibodies.  Several months ago the FDA created stringent guidelines for the vaccine companies to follow.  The Phase 3 trials are randomized controlled trials and everyone except the Data and Monitoring Safety Board (DMSB) know which volunteers were vaccinated and which received placebo.  The number of volunteers who developed symptoms and needed to have a +Covid test were predetermined and 62 was established as the first time the DMSB (Scientists independent of the study) could look at the data.  By the time the DMSB received, analyzed the data, and met on Sunday, there were actually 94 symptomatic and Covid-19 +cases, more than 90% of them in the placebo group.  The only other parameter reported was safety - and only minor reactions to the injections were found.  Read Below

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The DMSB will next look at the data after there are 164 symptomatic and Covid-19 virus+ volunteers.  Then the trial will be unblinded and huge amounts of data will be studied.  A decision will then be made re: an application to the FDA for an Emergency Use Authorization.  Half of the volunteers need to be at least 2 months beyond their 2nd dose of vaccine.  And there must be at least 5 severe cases of Covid 19.  These are some of the requirements that the FDA established for all vaccine applications.

Some additional facts about this vaccine:

Pfizer and BioNTech, a German company, developed the vaccine.  The US did not contribute financially, (i.e it was not part of Operation Warp Speed). but the German Gov't did contribute millions.  The US has an agreement with Pfizer/BioNTech to purchase 100 million doses of the vaccine - that's it. If the efficacy and safety are as good after the 164th sick volunteer is counted, the placobo patients may be vaccinated, thereby ending the randomization.  Antibody production and T cell immunity still need to be assessed as part of the effectiveness assessment and the data from every 44,000 plus volunteer needs to reviewed  However the original vaccinated patients will be followed for a total of 24 months to assure there is no late vaccine side effect.  There will also a 4th Clinical trial - which is called "Post-Marketing" for everyone who subsequently received the vaccine.

Why should we do a happy dance?  It is exciting that the effectiveness is so high - proving the concept for an mRNA vaccine platform.  No one really knew whether this would work for either Moderna of Pfizer.  Secondly, the epidemiologists are predicting a Fall and Winter pandemic "from Hell" - i.e. the virus is already surging in the US, not rounding the corner.  High risk health care workers may be vaccinated before the end of 2020.  But everyone else will have to wait for manufacturing to ramp up.  Unfortunately this vaccine must be maintained frozen at -100 degrees F, and there must be national plan for distribution to accomplish that.

November 7, 2020

Could This Be One Answer to Covid-19 Infection?

A nasal spray that blocks the SARS-CoV-2 virus prevented Covid-19 in a study when tested on ferrets, which are commonly used to study influenza, SARS, and other respiratory viruses.  If it works in humans, it could be a new way to fight the pandemic.  The effect of the spray lasts 24 hours, so a daily spray up the nose (like Flonase for allergies) could prevent infection (New York Times Nov 6).

The spray attacks the virus directly, preventing binding of the virus spike protein to nasal mucosal cells.  The spray is a cholesterol particle linked to a chain of amino acids (linopeptide), which matches a stretch of the amino acid on the virus spike protein.  The linopeptide binds to an amino acid chain on the virus spike protein blocking cell attachment and cell entry.  The study was a randomized, placebo controlled trial in which sprayed ferrets were caged with placebo and infected ferrets.  None of the sprayed ferrets became infected in 24 hours and all of the placebo ferrets were infected.  Four different strains of the virus were tested in the experiments.  Read Below

 

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This has been a really hard week - I almost decided to forego my weekly tiny doses of science in order to manage my anxiety and fear for what could happen in our country.  My life extends from WWII, Cuban missile crisis sitting it out in my college dormitory, JFK assassination, through Civil Rights era protests, Vietnam, financial crises, and 9/11 in my hometown - beloved Manhattan.  I can't remember ever being this afraid of the future for my children and grandchildren. 

 

November 4, 2020

Sars-CoV-2 Vaccine Update

There are 5 Covid-19 Vaccines in Phase 3 Clinical Trials.  Two of them may apply for an Emergency Use Authorization (EUA) within the next one or two months.  Moderna has completed enrollment of 30,000 volunteers - half in the placebo and half in the treatment group.  They slowed their enrollment briefly several months ago in order to enroll more persons of color, patients 65+, and volunteers with comorbidities. Pfizer has enrolled 42,000 out of their goal of 44,000 and they have added a group of volunteers between 12 and 18 years old.  Each company has an independent Data Safety Monitoring Board, scientists who will analyze the data when a target number of volunteers have developed Covid-19. 

The Board will initially review the data without knowing who received the vaccine and who received placebo.  Then hey must be able to demonstrate at least 50% efficacy when comparing Covid-19 cases in the vaccine and placebo groups, and no serious side effects. In order to evaluate safety both companies must wait for two months after at least half of the volunteers have received both vaccine doses before applying for approval from the FDA.  Continue Below

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They can then apply to the FDA for an Emergency Use Authorization or a Biologic License Approval. EUA are usually reserved for instances in which there is proven efficacy and minimal adverse effects and the benefits must outweigh the risks.  However when EUAs are granted, there is a substantial chance that the the clinical trial will not continue for the full 24 months of followup.  There was discussion at the FDA meeting that the company might want to vaccinate the placebo group right away, thereby ending the Randomized Placebo-Controlled trial that would provide definitive data for efficacy and long term safety.

The public rarely knows as much about the development of a vaccines - the fastest vaccine took 4 years to make, test, and distribute.  But we all want very effective and safe vaccines, and the companies are not willing to rush through the requirements.  A Biologic License Approval takes longer to assess and approve and with the current surge in cases many more people would die.  Difficult decisions must be made.

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