Miljoen study of exercise capacity after Pfizer booster

Nov.21 2022. Buyer beware for endurance athletes

This study from Belgium was released on November 21, 2022. 42 endurance athletes were given fitness tests and echocardiograms before and seven days after receiving Pfizer-BioNTech vaccine.

The central finding of their study: overall cardiopulmonary fitness levels reduced in the group. Eight of 42 athletes had a reduction in VO2 Max (a form of stress test that measures the body’s efficiency in using oxygen during exercise) which was the equivalent of having aged ten years. This is the -8.6% dashed line.

We may further note that the leftmost bar in this chart indicates an individual whose VO2max declined by almost twenty percent - which would presumably indicate the equivalent of having aged twenty years.

The rightmost bars on this graph indicate athletes who had an improved VO2max test after the booster. One participant’s VO2max score improved by 10%.

If the effects of the booster on exercise performance were random or insignificant, this graph should be symmetrical, with an equal number of low and high performers. Instead, it is markedly skewed towards low performance on VO2max testing after Pfizer-BioNTech booster.

When placed alongside the Mansanguan 2022 study which demonstrated a significant level of cardiac disease after second Pfizer-BioNTech vaccine doses in young men in Thailand, Miljoen 2022 indicates some cause for concern among athletes. It may also raise interest in the sports medicine community for pre and post testing of endurance athletes using VO2max.