Covid Vaccine Side Effects
Note that this information pertains only to the Pfizer/BioNTech COVID-19 mRNA Vaccine BNT162b2, and is excerpted from the gov.uk “Information for Healthcare Professionals on Pfizer/BioNTech COVID-19 vaccine”.
This vaccine in administered intramuscularly after dilution as a series of two doses at least 21 days apart. Individuals may not be maximally protected until at least 7 days after their second dose of the vaccine. This vaccine may not protect all vaccine recipients.
The most frequent adverse reactions (which were usually mild or moderate in intensity and resolved within a few days after vaccination) reported were:
Pain at the injection site >80 %
Myalgia (pain in a muscle or group of muscles) >30%
Arthralgia (pain in a joint) >20%
Pyrexia (fever) >10%
The frequency of adverse reactions reported in clinical studies are:
Very Common (1 in 10): Headache, arthralgia, myalgia, injection site pain, fatigue, chills, pyrexia
Common (1 in 100 to < 1 in 10): Redness at injection site, injection site swelling, nausea
Uncommon (1 in 1,000 to < 1 in 100): Lymphadenopathy; malaise
Rare (1 in 10,000 to < 1 in 1,000): Acute peripheral facial paralysis
Very Rare (< 1 in 10,000): none listed
Not Known (cannot be estimated from available data): Anaphylaxis (serious allergic reaction), hypersensitivity
The safety of this vaccine in children under 16 years old has not been established.
There is limited experience with the use of this vaccine in pregnant women, so administration during pregnancy should only be considered when the potential benefits outweigh any potential risks for the mother and baby. It is unknown whether the vaccine is excreted in human milk.
No studies have been performed to assess interaction with other medicinal products or other forms of interaction.
Individuals receiving anticoagulant therapy or those with a bleeding disorder should not be given the vaccine unless the potential benefit clearly outweighs the risk of administration.
Immunocompromised persons, including individuals receiving immunosuppressant therapy, may have a diminished immune response to the vaccine. No data are available about the accompanying use of immunosuppressants.
Events of anaphylaxis have been reported. Appropriate medical treatment and supervision should always be readily available in case of an anaphylactic reaction following the administration of the vaccine.
Close observation for at least 15 minutes is recommended following vaccination.
Terry Pfau DO, HMD