A third virus surge is on in the U.S.    Winter is here and people are enclosed more often.  This gives SARS-CoV-2 a much better chance to spread among us.

As several manufactures close in toward the end of their phase 3 (final phase) COVID-19 vaccine clinical trials, anticipation grows.   The FDA and its advisory board will review the data this winter and determine the merits of safety and efficacy of the vaccines. Hopefully one of the candidate vaccines in development will be approved for licensure.  Whatever the result long term follow up will be required of vaccine recipients to determine if any safety issues occur beyond the initial observation period.  But will a vaccine be the savior.

The studies were established to observe a 60% effect of the vaccine (but may be approved if even showing a lower effect).  Here is a key calculation:

According to many polls at most 40% of Americans said they would take a vaccine.  Let us bump that up to 50% to be conservative

50% x 60% efficacy (at best) = 30% persons protected, assuming everyone gets the product.  This does not get the country anywhere close to herd immunity, which requires between 60 and 70% seropositive individuals.

Now, we know that it will take some time for everyone to get the vaccine.  First, the health care workers, and aged and other high risk individuals will be first to get it, followed by military. 

This means that for at least the next year or two we need to continue to follow masking procedures, social distancing, handwashing, and whatever it takes to reduce transmission.

Additional safe therapeutic developments will be necessary for treatment of COVID-19

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