Another Week of Confusion

The COVID-19 pandemic is confusing at baseline, but now others who should know better are aggravating the situation. My post this week is a little verbose, I'll try to return to concision next week.

To Boost or Not to Boost, That is (Not) the Question

Most evidence points to a need for a booster vaccine dose for the mRNA vaccines, but the timing is far from clear. So, I was dismayed to see that the main message this week was that everyone (some more than others) needs a booster 8 months following completion of the 2-dose series. Buried in the pronouncements was the fact that FDA and ACIP will look closely at the data to make a judgment. It is absolutely appropriate to plan for the possibility that booster vaccine doses will be administered in September, but don't use the need for advanced distribution planning as a surrogate for an 8-month booster timing. Let FDA and ACIP do their jobs.

I say this after having gone over the evidence with my best fine-tooth comb. Three reports appeared as early releases August 18 in MMWR. All are well-designed and well-reported studies utilizing different databases and study designs. One looked at hospitalizations in New York state from early May to late July, another at duration of effectiveness of mRNA vaccines March through July throughout the country, and the third (and only CDC study) looked at vaccine effectiveness in US nursing home residents March through July. The most important take-home point from all 3 studies is that the mRNA vaccines are all still tremendously effective at preventing severe illness and death. (The Janssen/J&J vaccine hasn't been in use long enough to make any concrete conclusions about changes in efficacy.) There was a slight decline in effectiveness in some groups recently, but whether this is due to waning of vaccine immunity, the appearance of the delta variant, or both isn't possible to sort out yet.

What really has had the steam coming out of my ears lately is the discussion of Israeli data, as yet unpublished in a peer-reviewed journal. It seemed to me to be a clear error in statistical analysis and reporting, something I would use an example in my old EBM classes. Just this week I found support in the form of an online site that explains the problem far better than I could. It is an example of Simpson's Paradox (Edward Hugh Simpson, not Homer). Briefly stated, Simpson's Paradox is "a trend or result that is present when data is put into groups that reverses or disappears when the data is combined." More simply, if one is not careful to take into account confounding variables, you can end up with conclusions that are the exact opposite of the truth. In the case of the Israeli data, reanalyzing numbers available from the Israeli government data dashboard showed that it is likely that claims of waning vaccine efficacy are a byproduct of higher vaccination rates in the elderly, who have more underlying risk factors, compared to the highly unvaccinated group of teenagers and young adults. When you correct for the confounding, or hidden, variables, the vaccine efficacy looks great for all ages.

Please Don't Administer Vaccines Off-Label!

I received an email from the mother of a child enrolled in our COVID-19 vaccine trial at Children's National. He received his 2 injections (either vaccine or placebo) a couple months ago and is doing very well, but mother is concerned because he will start school soon and has very mild asthma. (She felt this was a risk factor for severe disease but plenty of studies show that this is not a risk.) She had a few great questions, but what concerned me most is that she had heard from others that some healthcare providers were planning to administer COVID-19 vaccines to children 9-11 years of age which of course is not an authorized age group. I don't know if this is true, but I do know this is one of the worst ideas I've heard, right up there with drinking bleach.

DO NOT make up your own vaccine schedules. How would you know what dose to give a 9 year old child? What if there is a severe adverse reaction? Remember also that you need to report all vaccine doses administered. If you want to get involved with giving COVID-19 vaccines to children under 12, join a clinical trial. 'Nuff said.