The blood clots that might be linked to the new vaccines are part of a condition known as cerebral venous sinus thrombosis (CVST), and they have not been well studied. CVST occurs when a clot (a mass of coagulated blood) forms in the brain’s venous sinuses, preventing blood from draining out of the brain and potentially leading to hemorrhage or stroke. Symptoms of CVST in these cases seemed to appear within two weeks of receiving the vaccine and were accompanied by low platelet levels, making treatment more complicated. The pause on vaccine distribution is designed, in part, to give experts time to determine the best treatment options.
By contrast, we know a lot about deep vein thrombosis (DVT), the blood clot condition related to the pill. This type of clot usually forms in the lower legs, thigh, or pelvis. The biggest risk with DVT is that a portion of the clot breaks off and travels through the veins to the lung, causing a pulmonary embolism. Risk for DVT is increased when someone is on hormonal birth control that contains estrogen (most hormonal birth control contains both estrogen and progestin) but also after surgery, during pregnancy or right after childbirth, and after extended periods of air travel.
We are a society of headline readers who often skip the details in favor of fear. Comparisons may seem like an easy way to make abstract risk concepts relatable, but they aren’t particularly useful. Anyone who has ever expressed a fear of flying has undoubtedly been told that they are more likely to die in a car accident. But all it takes is one headline about a plane crash killing everybody on board, and statistical probability becomes meaningless.
The job of those promoting the vaccine has become exponentially harder this week, but those of us who have spent careers promoting correct and consistent contraception use must ask the media to stop trying to help by using the pill as a comparison measure. This can only cause confusion, and possibly unintended pregnancy.