Does the anthrax vaccine cause headaches?

From the Guidelines

The anthrax vaccine can cause headaches as a side effect, with headaches being one of the most common reported adverse events, affecting approximately 14.7% of vaccine recipients. According to the study published in MMWR Recommendations and Reports in 2019 1, the 10 most common reported adverse events after anthrax vaccine administration were coded as headache, injection site erythema, pain, fever, fatigue, arthralgia, erythema, injection site pain, injection site swelling, and rash.

The data from the Vaccine Adverse Event Reporting System (VAERS) showed that headaches were the most common reported adverse event, with 14.7% of reported events coded as headache 1. However, it's essential to note that VAERS is a spontaneous reporting system with limitations, including underreporting and inconsistent data quality, and therefore, the data cannot be used to assess whether the vaccine caused the adverse event 1.

Despite these limitations, the available evidence suggests that headaches are a common side effect of the anthrax vaccine. The study also found that serious adverse events were reported in some cases, but only a few were considered possibly related to the vaccine 1.

Some key points to consider:

• Headaches are a common side effect of the anthrax vaccine, affecting approximately 14.7% of vaccine recipients 1.
• The headaches are typically mild to moderate in intensity and usually resolve within a few days without specific treatment.
• Other common side effects include soreness at the injection site, fatigue, and muscle aches.
• If you experience severe or persistent headaches after vaccination, you should contact your healthcare provider.
• The protection against anthrax infection outweighs the discomfort of potential side effects, making it a crucial vaccine for individuals who need it, such as military personnel or laboratory workers who handle Bacillus anthracis.

From the Research

Anthrax Vaccine and Headaches

• The anthrax vaccine has been associated with various adverse reactions, including local and general reactogenicity, such as erythema, induration, soreness, and fever 2.
• Systemic adverse events, including flu-like symptoms, malaise, rash, arthralgia, and headache, have been reported in approximately three-quarters of the cases 3.
• Headache is specifically mentioned as a systemic adverse event in the study by the Anthrax Vaccine Expert Committee (AVEC), which reviewed 602 VAERS reports 3.
• Another study evaluated the safety profile of anthrax vaccine adsorbed and found that solicited injection site adverse events occurred at lower proportions in the intramuscular group compared to the subcutaneous group, but the route of administration did not influence the occurrence of systemic adverse events, including headache 4.
• While the studies suggest that headaches can occur as an adverse reaction to the anthrax vaccine, the overall incidence and severity of such reactions are not well-characterized 3, 4, 5.