Dean's Notes

There may be good news with regard to Colorado’s COVID-19 epidemic. The number of Coloradans hospitalized with COVID-19 has dropped four days in a row through yesterday and the latest modeling report shows that the effective reproductive number (equivalent to R₀) is dropping. If the drop is sustained for a few more days, perhaps Colorado is on the verge of a decline in the fifth surge. The report, however, also offers projections showing a continuing rise, if behaviors of Coloradans lessen the level of transmission control. Fortunately, we are unlikely to reach the December 2020 peak nor to breach hospital capacity. But the present surge has filled hospital beds in Larimer County where capacity has been at 100% since late August.

Nationally, hospitals in the South and Southwest are stressed in regions corresponding to those with lower vaccination rates. In Colorado, an updated graphic on the Colorado Department of Public Health and Environment (CDPHE) website indicates that 83% of those hospitalized across the state are unvaccinated. Most of these hospitalizations were preventable. The number of deaths that could have been avoided can be estimated. The New York Times released an analysis last week that 16,000 deaths could have been avoided had all states achieved the same vaccination rate as the fastest state’s rate four weeks prior.  

Those seeking clarity on the need for a third COVID-19 vaccine shot – a booster – may have been confused by the latest scientific reports and Friday’s decision by the FDA’s Vaccines and Related Biological Products Advisory Committee. Papers published last week in The Lancet and the New England Journal of Medicine were seemingly conflicting in their conclusions. 

The former is a commentary authored by global leaders in public health, arguing that the evidence supporting boosting is weak and that protection against more severe COVID-19 remains adequate. A key overall conclusion: “The limited supply of these vaccines will save the most lives if made available to people who are at appreciable risk of serious disease and have not yet received any vaccine.” Questions have been raised by many concerning the ethics of using vaccines for booster shots in richer countries while the vaccination rate is far too low in poorer countries.

The paper in the New England Journal of Medicine describes the results of administering a third dose of the Pfizer-BioNTech in Israel. The experience in Israel had been cited as one reason for providing a third shot, but it had not been well described previously. The findings are striking, showing a very strong protective effect of the booster within 12 days of its administration among people who had already received two doses. Those not receiving a booster compared with those who did had an 11-fold increased risk for infection and a 20-fold increased risk of severe illness.  

We await the FDA’s decision. On Friday, its Vaccines and Related Biological Products Advisory Committee recommended a third shot for those 65 years and older or at high risk for severe disease, but rejected a booster for the full population. While we will learn more about the need for a third dose as the interval since vaccination lengthens for those vaccinated months ago, a report in CDC’s Morbidity and Mortality Weekly Report shows continued effectiveness of the three vaccines used in the United States. At more than 120 days after full vaccination, the estimates of vaccine effectiveness against hospitalization were: Moderna-92%, Pfizer-BioNTech-77%, and Johnson & Johnson-68%. Yes, 92% is greater than 77% and 68%, but these latter figures also indicate substantial protection. There will eventually be third doses for all, when the evidence has grown and is certain enough for the FDA to make a decision. 

Jonathan Samet, MD, MS
Dean, Colorado School of Public Health