Mario Tama/Getty Images
- Not everyone gets side effects after their COVID-19 vaccinations.
- You're still protected even if you don't have a noticeable reaction.
- Immune systems vary, but the Pfizer and Moderna vaccines are highly effective.
- See more stories on Insider's business page.
It's the day of your second shot of the COVID-19 vaccine. You make sure to stock up on fever-relievers, hydrate as much as possible, and tell your boss you're taking tomorrow off from work.
But after all that preparation, you wake up the next morning feeling fine – maybe a little more tired than usual, but not nearly as bad as you expected. You wait all day for the side effects to hit, and you find yourself wondering, "Did the vaccine even work?"
"Everyone was complaining about feeling really achy, or at least having chills, so I was fully prepared. I bought Pedialyte, I bought Tylenol – like I 100% expected to wake up and feel like sh–," one 29-year-old woman told Insider.
She asked to remain anonymous because in the days before she got her second Pfizer shot, she partook in something of a wild weekend that involved illegal drugs.
The day after the shot, she felt a bit light-headed but otherwise fine, which had her frantically searching the internet to see if the cocaine and MDMA had somehow interfered with her immune response.
Her lack of side effects was more common than she thought. Although side effects are proof of an immune system hard at work, not everyone will experience a noticeable reaction after getting vaccinated - and that doesn't mean it's not working.
You can be protected against COVID-19 without side effects
Usually, people want to avoid unpleasant reactions like fever, achiness, and fatigue. But with the COVID-19 vaccines, it's another story.
"I think this is the first vaccine in the history of vaccines where people complained about not having side effects," Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia, told Insider.
That's because people are starting to see side effects for what they are: products of your immune response to the vaccine. But it's also possible to have a successful immune response without any noticeable effects.
Stephanie Brown, 32, told Insider she had no side effects at all after both Pfizer shots. She was a bit concerned about her protection, but when she donated blood months later, she found out that she did indeed have antibodies for COVID-19.
Offit said it's important to remember that while roughly half of vaccine trial participants didn't report side effects, the efficacy of the Pfizer and Moderna vaccines was close to 95% - meaning that many people who didn't have side effects were still protected.
While immune responses vary, the vaccines are highly effective
Sophie Kleeman, an editor at Insider, hardly felt anything after her second Pfizer shot. Even the arm pain the 29-year-old had experienced after the first shot was "barely even noticeable" the second time around.
Meanwhile, many of her friends were completely bedridden after their second shots of Pfizer and Moderna. Their varied experiences prompted debates about who was better off.
"I did have quite a few good natured sparring matches over who has a stronger immune system," Kleeman said. "They flipped it on me, and they said the reason that younger people have stronger reactions is because their immune systems are stronger."
It's true that people under 65 are more likely to have side effects thanks to their robust immune systems, Offit said. But that variation is even further proof that you don't need side effects to develop protection against COVID-19, since the vaccine efficacy for folks over 65 was "virtually identical" to that of young people.
"The critical question is, do you get enough of an immune response to protect you," Offit said. "And in this situation, the answer is yes, you do - even absent those symptoms."
Dit artikel is oorspronkelijk verschenen op z24.nl