a little discomfort; a little pain with heaviness feeling; This is a spontaneous report from a non-contactable consumer or other non-healthcare professional (parent). A 34-years-old male patient received bnt162b2 (BNT162B2, PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection), dose 1 via an unspecified route of administration on 25Jun2021 (Batch/Lot number and Expiry date was not reported) as DOSE 1, SINGLE for covid-19 immunisation. The patient medical history and concomitant medications were not reported. On an unspecified date, the patient experienced a little discomfort and a little pain with heaviness feeling. Reporter reported that his son received vaccine and experienced a little discomfort for about 24 hours. He explained it as a little pain with heaviness feeling. It has eased up. Just a little discomfort now. Side effects that have been reported with the Pfizer-BioNTech COVID-19 Vaccine included muscle, injection site & arm pain. The reporter asked if you should return in 21 days for the second Pfizer Covid 19 Vaccine. In response it was stated that the Pfizer-BioNTech COVID-19 Vaccine is a suspension for intramuscular injection administered as a series of two doses (0.3 mL each) 3 weeks apart. Administer the Pfizer-BioNTech COVID-19 Vaccine intramuscularly. Reporter stated that she heard how the Johnson Vaccine may cause clotting. She thought she heard something about a female getting a clot to the brain and asked if Pfizer has any information for females with bleeding disorders or clots receiving the Pfizer Covid 19 Vaccine. The reporter also asked about the need for a booster dose (3rd dose) and if Pfizer is investigating the need for a booster dose. Response was provided as part of Pfizer and BioNTech continued efforts to stay ahead of the virus causing COVID-19 and circulating mutations, the companies provided an update on booster dosing on 9Jul2021. Please note that the use of a 3rd or booster dose is not recommended or authorized, and Pfizer does not suggest the use of the vaccine in any manner other than as described authorized. Initial data from the ongoing study of booster doses demonstrated a consistent tolerability profile and high neutralization titres against the wild-type virus (the naturally occurring non-mutated virus) and the Beta variant. It is thought that the effects seen against the Beta variant may also be seen in the Delta variant. We are doing studies to confirm this. We expect to publish the data soon in a peer-reviewed journal and submit to regulatory authorities in the coming weeks. Note to frontline: This FAQ should only be used specifically asks about the Pfizer statement on booster doses. For  with general inquiries about booster doses, please refer to the titled Administration of More Than a 2-Dose Series (Booster Dose). should be referred to their for further discussion. The reporter stated that a family member who went in to get the vaccine a few days ago. They were given a receipt that has the vaccine should be given in the left arm and asked if the Pfizer Covid 19 Vaccine should only be administered in the left arm. In response it was stated that administer the Pfizer-BioNTech COVID-19 Vaccine intramuscularly. Also asked that according to the person who administered the Pfizer Covid 19 Vaccine said that it has to be mixed prior to giving, if the information is correct that the vaccine must be mixed prior to administering. In response it was stated that Add 1.8 mL of 0.9% Sodium Chloride Injection and administer the Pfizer-BioNTech COVID-19 Vaccine intramuscularly. The clinical outcome of the events was unknown.  No follow-up attempts are possible. No information can be expected.