Pfizer coronavirus vaccine side effects

After several tests in several groups of people and countries, there were mainly three brands of vaccines that were approved for their use in the United States, which were Pfizer BioNTech, Moderna, and Johnson & Johnson. Since the first one is the one being delivered more commonly to most of the population, the question regarding Pfizer coronavirus vaccine side effects specifically is starting to arise.

Pfizer’s vaccine was developed in the United States, it requires two doses separated by 21 days and it is an mRNA vaccine. This type of vaccine works by teaching our cells to produce pieces of proteins, which trigger the immune reaction.

Does it really work?

Yes. As we mentioned before, it is one of the three authorized vaccines in the United States and the most commonly used. Its functionality, efficiency and side effects in the population have been tested by the World Health Organization (WHO) and the Public Health England (PHE).

Although Pfizer’s vaccine (as any other) has had some potential risks, the data reviewed by WHO supports the conclusion that the known benefits of the vaccine far outweigh the potential risks. It is still recommended for you to get vaccinated. (2021)


Pfizer coronavirus vaccine has proven to provide from 95% to 97% of protection against the virus after 7 days of the second dose, therefore, it is essential that you get both recommended doses to be safe. (WHO, 2021)

The vaccine was also found to reduce transmissions, including those that did not show symptoms all around the world. It was tested in several races, ethnicities, and groups of age.
Still, none of the existing vaccines can prevent transmission 100%, therefore, it is still recommended to keep following the established measures such as constantly washing your hands, wearing a mask, and practicing social distancing.

Although the three vaccines that are currently approved in the country have a very respectable efficiency percentage, here we show a comparison of the proven efficiency in all three of them according to healthline:

  • Pfizer: 95% – 97% efficiency in preventing an infection in people that have not had the infection.
  • Moderna: 94.1% efficiency in people who have not yet had the infection.
  • Johnson & Johnson: around 72% overall efficiency and 86% efficiency against severe illness.

Pfizer coronavirus vaccine side effects

Side effects of the Pfizer vaccine are very similar to the ones of every other brand:

  • Slight pain, redness and swelling in the area where you got the shot
  • A sensation of tiredness
  • Headaches
  • Body aches or muscle pains
  • Chills
  • Fever
  • Nausea

Remember that whichever side effects you have, they should only last for a couple of days and they should not be severe. If your side effects last more than three days or you have severe symptoms like chest pain or difficulty breathing, you should call your doctor right away.

Take into consideration that the side effects can be a little stronger after the second dose of the vaccine.

How can I alleviate the side effects?

  • To reduce the pain in the area where you got the shot, you can apply a cool, wet washcloth over the area and exercise your arm.
  • To reduce the discomfort in the body (especially the fever) you must drink plenty of fluids and dress lightly.
  • If the discomfort or the headaches are too strong, you can ask your doctor if you can take over-the-counter medication such as ibuprofen or aspirin.

Every vaccine currently authorized has shown to have side effects, but they only last a couple of days and are not severe. Regardless of the side effects, it is highly recommended that you get vaccinated as soon as possible.

Remember that at Formé Medical Center we have a highly qualified team of healthcare professionals, and we are constantly having vaccination campaigns, you can learn more about these by calling us at 914 723 4900