There is a potential for injection site reactions (redness, swelling, and pain) as well as fever, fatigue, headache, chills, nausea, vomiting, diarrhea, muscle pain, and/or joint pain. These adverse reactions are commonly seen with other vaccines. There may be other reactions that are not currently known. If you are receiving a two-dose vaccine, it is important that you receive the second dose to ensure the vaccine is effective, even if you experience side effects after the first dose.
If you have a severe allergic reaction following the first dose of a two-dose vaccine course, such as anaphylaxis, you should not receive the second dose. The incidence of this occurring is low, about one in six per million doses.