claim: suspicions grow that nanoparticles in pfizer 's covid-19 vaccine trigger rare allergic reactions.
evidence_1: severe allergy-like reactions in at least eight people who received the covid-19 vaccine produced by pfizer and biontech over the past 2 weeks may be due to a compound in the packaging of the messenger rna (mrna) that forms the vaccines main ingredient, scientists say.", "patients with severe allergies in the us are getting nervous about the possibility that they may not be able to get vaccinated, at least with those two vaccines, togias wrote in an invitation to meeting participants.", "some allergists and immunologists believe a small number of people previously exposed to peg may have high levels of antibodies against peg, putting them at risk of an anaphylactic reaction to the vaccine.", 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  "niaid is also setting up a study in collaboration with fda to analyze the response to the vaccine in people who have high levels of anti-peg antibodies or have experienced severe allergic responses to drugs or vaccines before.")