Different vaccines can cause various adverse reactions even though it is prepared, handled, and administered cautiously.
Most people do not face severe side effects; reactions are usually mild and go away quickly on their own, as per the U.S. Department of Health & Human Services. The most common side effects are pain, swelling, redness, mild fever, chills, fatigue, headache, muscle and joint aches.
The Centers for Disease Control and Prevention(CDC) found that allergic reactions are a common concern for vaccine providers. But anaphylaxis (severe allergic reaction) following vaccination are rare, occurring at a rate of approximately one per million doses for many vaccines. Some of the severe reactions may be complicated by the onset of syncope (loss of consciousness). Syncope may occur after vaccination and is most common among adolescents and young adults. However, to prevent allergic reactions, it is essential to identify individuals at increased risk by obtaining a history of allergy to previous vaccinations and vaccine components that might indicate an underlying hypersensitivity.
The U.K. was the first Western country to authorize a Covid-19 vaccine and began its vaccination program with priority recipients, including healthcare staff.
Recently two NHS staff members suffered allergic reactions -anaphylaxis after they had the Pfizer vaccine shot. Following this, Dr. June Raine, Chief Executive of the Medicines and Healthcare products Regulatory Agency (MHRA), on December 09, 2020, issued updated guidelines to the COVID-19 vaccination centers about the vaccine's possible allergic reactions. The guidance suggested that people with a history of significant allergic reactions should not take the Pfizer/BioNTech COVID vaccine. The two are reportedly recovering well.
Hence, it is common to have allergic reactions when a vaccine is injected into an individual. The responses may be minor or significant, depending on how the body reacts to the vaccine.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.