Newsletter Vol2 №13 minute read

In newsletter by Steven Kornweiss, MDLeave a Comment

  1. New in Case Reports: A Case of Amenorrhea in a Female Crossfit Athlete Successfully Treated with Non-Pharmacologic Interventions
  2. Covid-19 mRNA Vaccine Efficacy

New in Case Reports:

A Case of Amenorrhea in a Female Crossfit Athlete Successfully Treated with Non-Pharmacologic Interventions

Read the case here.

Case Overview: I am extremely thankful for the amazing people who gave me a chance to work with them in my first year of private practice. One of these people is an impressive recreational athlete who encountered a problem that many athletes are probably familiar with — training-recovery mismatch. This mismatch, which can be from over-training, under-recovering, or a combination of the two, can take many forms.

Perhaps the most notable form is called functional hypothalamic amenorrhea, or FHA for short. The primary sign of FHA is the loss of a woman’s menstrual period. FHA is a condition that can occur in women in a variety of circumstances (a corollary condition also occurs in men, but it is under-recognized and poorly described in the medical literature for obvious reasons). One common circumstance that can lead to FHA is high-volume and/or high-intensity training with simultaneous caloric restriction. However, sleep deprivation, psychological stress, and other conditions can contribute or even primarily cause FHA. The solution to FHA in the context of athletics is usually a reduction in training and stress, and an increase in energy intake and sleep. Put simply, the patient must exercise less and eat more.

But, how much less exercise, how much more food and sleep, and for how long? How quickly does the condition resolve? Could something else be causing the problem other than too much exercise and too little nutrition?

This past year, I helped one of my clients answer these questions and many more. She has given me permission to write up her case so that the lessons learned might provide context and useful information for others who have similar problems. Her particular case is now written up in detail (case history, timeline, labs, and analysis) on my website as a reference for anyone who is in, or who knows someone in a similar situation.

You can read this case here.

Covid-19 mRNA Vaccine Efficacy

I’ve been asked several times recently what it means that the vaccine is "95% effective."

It does not mean that 95 times out of 100 exposures an individual is protected from contracting Covid. It does not mean that symptoms are reduced by 95% in vaccinated patients who contract Covid — though there likely is a symptom-mitigating effect in vaccinees who contract Covid.

It does mean that the vaccine is effective in preventing symptomatic infection in members of a group of recipients compared to individuals in a placebo group of non-recipients. But, to get a more concrete idea of exactly how effective this vaccine is, it’s worth looking at the actual numbers from the clinical trial and the trial definition of "vaccine efficacy."

From the most recent publication in NEJM regarding the Pfizer BioNTech Covid-mRNA Vaccine:


"Among 36,523 participants who had no evidence of existing or prior SARS-CoV-2 infection, 8 cases of Covid-19 with onset at least 7 days after the second dose were observed among vaccine recipients and 162 among placebo recipients. This case split corresponds to 95.0% vaccine efficacy (95% confidence interval [CI], 90.3 to 97.6; Table 2)."

How was vaccine efficacy calculated?

"Vaccine efficacy was estimated by 100×(1−IRR), where IRR is the calculated ratio of confirmed cases of Covid-19 illness per 1000 person-years of follow-up in the active vaccine group to the corresponding illness rate in the placebo group."

Let’s look at the actual numbers.

Figure 3. Efficacy of BNT162b2 against Covid-19 after the First Dose.

In the vaccine group, only 9 out of 21,669 participants tested positive for Covid-19 during a roughly 100 day surveillance period after the 2nd vaccine dose.

So, in this time period, the rate of infection in vaccine recipients was 9 out of 21,669 — 0.04%. In other words, 99.96% of vaccine recipients did not have symptomatic Covid-19 during the surveillance period. Compare this to 172 out of 21,686 in the placebo group — 0.8%. This is still a low infection rate, but it is nearly 20 times the infection rate in the vaccine group.

It is important to realize that many people were neither exposed nor tested during the surveillance period. Exposure was dependent on participant behavior, and testing was dependent on reporting of symptoms. There is no reason to believe these factors were unbalanced between the vaccine and placebo groups, but nonetheless, some caution must be used in interpretation of efficacy for these reasons.

However, whichever way you slice this, the bottom line is that the vaccine does in fact appear to be remarkably effective at preventing Covid-19 infections.

If you want to see a compilation of everything I’ve written on the Covid-19 mRNA vaccines thus far, you can go to this article on my website which I’ll be updating as I generate more content on the topic.

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