Coronavirus

  There is no doubt that COVID-19 vaccines are working beautifully to drive down COVID-19 cases in the USA.   With 170M Americans or 51% having had at least one dose of the vaccine, cases in the USA have dropped to a 14-mo low of 5 per 100,000.    However, there is a significant subpopulation of the USA, 10M or 3%, who may not be fully protected by the vaccines.   These include those (>6M) that are taking immunosuppressive drugs such as steroids used to treat organ transplants, cancers, or other medical conditions, and those who have compromised immune systems due to blood cancers and other diseases.   The original clinical trials for vaccines specifically excluded people who were taking immunosuppressive drugs to get their impressive 95% efficacy results.   Real-life studies were equally impressive since less than 3% of those sampled were immunocompromised.   More targeted real-life studies with immunocompromised patients show more dis...

Covid-19 daily cases started rising again about 4 weeks ago signaling the beginning of a fourth wave in the USA.   However, over the last week cases have resumed declining cutting short the fourth wave.   Is this a real indication of light at the end of the tunnel or are we just seeing the headlight of the oncoming train? 42.2% of the USA has been vaccinated with at least one shot to date (green part of the graph below).   This seems to be too low to meet the 70%+ threshold that is generally believed to be the vaccination level needed for herd immunity.   However, we have always asserted that while rigorous herd immunity with vaccines is the most desirable goal, effective human immunity may be reached earlier and allow the USA to flatten the COVID-19 infection curve.   Effective human immunity is a combination of natural immunity gained through infection by the SARS-COV-2 virus, vaccine immunity, and behavior immunity due to citizens rigorously practicing maski...

Covid-19 mRNA vaccines work very well in real life.   But as more data are analyzed it appears that certain groups of people such as seniors (65+) do not benefit as much from the vaccine.   We have been tracking the vaccine’s real-life efficacy through Florida’s Seniors First program to vaccinate everyone over 65 years old first.   As of April 19 th , 3.6M seniors or 80% have been vaccinated with 2.9M (64%) completing the two-dose regime.   The pace of senior vaccinations has slowed recently and this may be linked to the plateau and now rise in relative infection for seniors (see figure below).   There are several possible explanations for this observed phenomenon: 1.      Vaccine hesitancy expressed by 27% of Americans in recent polling,   Note that 80% of Florida seniors have already gotten their shot so polling answers may be more political posturing rather than reality.   Nevertheless, at some point before 100%, we will r...

The good news is that there are now 3 approved COVID-19 vaccines in the USA with more than enough doses to allow all American adults to be vaccine eligible by May 1 st .  Two of the vaccines, Moderna and Pfizer-BioNTech, have already proven to be very effective in the field.  These are two-dose vaccines that can take 6 weeks to achieve full protection.  One way to track real-life efficacy is through Florida’s Seniors First program to vaccinate everyone over 65 first.  As of March 13 th , 2.93M seniors or 65% have been vaccinated with 1.75M (39%) completing the two-dose regime.  If the vaccine is effective, the number of daily cases, hospitalizations, and deaths should all come down.  The graph below tracks the relative susceptibility of Floridians by age to SARS-CoV-2 infections.   Seniors have always been more careful to mask-up and social distance since the first COVID-19 cases appeared in Florida and killed hundreds of seniors last spring.  ...

Classic “herd immunity” is achieved when enough members of a population get infected and acquire natural immunity so that too few uninfected members are left to spread the disease.   The threshold percentage depends on how infectious the disease is and for COVID-19 it is not known but generally believed that 65%-75% of the population needs to develop immunity to stop this pandemic.   For humans, there are two more methods to slow or stop a pandemic: behavior immunity and vaccine immunity.   Governments can convince their citizens, or if necessary mandate, many public health policies that can mitigate the spread of disease.   Keeping your distance, wearing a mask, selective isolation, and improving personal hygiene are things that cattle can’t do but humans can and should do.   People in many countries such as Taiwan, New Zealand, Australia, and Vietnam have been able to control COVID-19 for over a year now without a vaccine or natural immunity.   Even in co...

The new US administration has made re-opening schools a priority .  There are many benefits to re-opening school s and certainly, re-opening schools are more important than re-opening bars and many other businesses.  But there are many risks as well.  One of the risks is the susceptibility of kids to COVID-19.  Kids suffer far fewer fatalities and hospitalizations than older adults (although kids could suffer long term ill effects with COVID-19).  The question really comes down to how easily do kids acquire the virus and how easily do they transmit COVID-19 to others and fuel the pandemic.    In Florida, most schools and universities reopened in late August 2020.   Since then the number of daily confirmed cases per capita has risen steadily for all age groups.   College and university-aged (18-24yrs) students are most active and mobile and show the highest cases per capita – currently 30% above average.   High school students (14-1...

Before noon on January 20 th , President Trump will leave his office.  At that time the reported death toll from COVID-19 in the USA will be over 400,000 – the exact number depending on who does the tallying.  Worldmeter will show 412k – real-time, Johns Hopkins will show 402k – lagging by a day, and CDC will show lower – lagging by a couple of days.  All these estimates understate the real toll history will attribute to Trump - over 500k Americans died on his watch.     COVID-19 death reporting has time lags and other issues. 1.      Accurately assigning the correct cause of death is sometimes more art than science.   There are the underlying cause and the proximate cause issue.   Sometimes COVID-19 starts a chain of events that lead to death many months later from lung, heart, kidney, liver, or diabetes problems that are not uniquely attributable to COVID-19.   The US CDC separately defines confirmed and probable...