What makes certain injections more painful than others?


For example, many people stated that the second round of the COVID 19 vaccine hurt more than the first. Then people who went on to get the booster claimed that hurt more than the first and second covid vaccines. What exactly is making the vaccines itself hurt?

In: 6

Not sure I heard that the second round hurt more, but that your body had a much larger immunoresponse than the first.

Needle size and sharpness. Some fluids need a larger needle to pas through, and some needles aren’t perfect out of the package. Also, experience of the needle-pusher comes into play (the needle needs to go straight in, straight out, and a perfect depth).
Also, the fluid itself is pushing outward from the injection site into nerve endings, which adds at least a small amount of discomfort to the mix.
This isn;’t even mentioning the miraiad of physiological and immunosuppressive reactions your body ignites at the site, as well, and the body can react quite differently each time.

I asked the pharmacist this question. He said that he changes the needle after piercing the vaccine bottle top. The second thing was to allow the alcohol to dry. He said that his last vaccine hurt. The alcohol was not yet dry.

Needle size, fluid amount, immune response, inflammation. Some people also have reactions not everyone does.

When I got a cortisone shot in my shoulder I had a response called a “steroid flare” which caused extra pain and discomfort for days. Which is the opposite effect that it is supposed to have.

Sometimes the injection just hits a nerve.

Other than that, it could be the skill of the person administering. A tentative hand will generally be more uncomfortable than someone who just darts it in there.

It could be the equipment. If the needle has been dulled by puncturing the top of the canister then it’s not going to go through the skin as well.

Finally, some shots have components that are specifically designed to irritate the tissue called adjuvants. This is to provoke the body into an outsized response, which allows less of the active ingredients to be used while maintaining full effectiveness.