From the Guidelines
Meningococcal vaccines, including MenACWY and MenB, commonly cause mild side effects, such as pain, redness, and swelling at the injection site, fatigue, headache, and low-grade fever, which typically resolve within a few days 1. The most frequent side effects of meningococcal vaccines include:
- Pain, redness, and swelling at the injection site, affecting roughly half of vaccine recipients
- Fatigue, headache, muscle or joint pain, and low-grade fever, occurring in about one-third of people
- Nausea or diarrhea, which are generally more common with MenB vaccines compared to MenACWY vaccines These side effects represent normal immune system responses as the body builds protection against meningococcal disease. According to the study published in MMWR Recommendations and Reports in 2013 1, the most frequently reported adverse events following MenACWY-D vaccination were fever (16.8%), headache (16.0%), injection site erythema (14.6%), and dizziness (13.4%). Serious allergic reactions are extremely rare, occurring in less than one in a million doses, and most people can manage mild symptoms with over-the-counter pain relievers, rest, and adequate hydration 1. Despite these temporary discomforts, the protection provided against potentially deadly meningococcal infections far outweighs the risk of these generally mild and short-lived side effects. It's worth noting that the safety and immunogenicity of both serogroup B meningococcal vaccines (MenB-4C and MenB-FHbp) have been evaluated in numerous published clinical trials, and both vaccines appear to provide significant protection against serogroup B meningococcal disease 1.
From the Research
Common Side Effects of Meningococcal Vaccines
The meningococcal vaccines, including MenACWY (meningococcal conjugate) and MenB (meningococcal B), have been found to have similar safety profiles across different age groups and populations 2, 3. The common side effects of these vaccines include:
- Local reactogenicity events such as swelling, pain, and redness at the injection site
- Systemic reactogenicity events such as fever, fatigue, headache, drowsiness, loss of appetite, and irritability 2, 3
Safety Profile of MenACWY-TT and MenACWY-CRM
The MenACWY-TT and MenACWY-CRM vaccines have been found to have acceptable clinical safety profiles across a wide range of age groups, including infants, toddlers, and pregnant women 2, 3. No safety concerns have been reported in special populations, and the vaccines have been proven to be immunogenic in various age groups and geographic settings 3.
Comparison of MenACWY and MenB Vaccines
The MenACWY and MenB vaccines have been found to be effective in preventing invasive meningococcal disease, with the MenACWY vaccine providing protection against four meningococcal disease-causing serogroups (A, C, W, and Y) and the MenB vaccine providing protection against serogroup B 4, 5. The use of a pentavalent meningococcal vaccine (MenACWY-TT/MenB-FHbp) has been recommended for prevention of invasive disease caused by N. meningitidis serogroups A, B, C, W, and Y among persons aged 10-25 years 4.
Real-World Evidence of Vaccine Effectiveness
Real-world evidence has shown that the MenACWY-CRM vaccine can reduce IMD incidence even in high-exposure groups, and that vaccination of adolescents and adults can reduce nasopharyngeal carriage for serogroups C, W, and Y 3, 6. The 4CMenB vaccine has also been found to provide direct protection against MenW disease, with an estimated 69% reduction in MenW cases among age-cohorts that were fully eligible for 4CMenB 6.