The Serogroup B meningococcal vaccine protects individuals from Neisseria meningitidis serogroup B, a bacterium capable of causing severe, rapidly progressing illness. Its primary purpose is to prevent meningococcal disease, which can lead to life-threatening conditions like meningitis and blood poisoning.
Understanding Serogroup B Meningococcal Disease
Meningococcal disease is a serious infection caused by the bacterium Neisseria meningitidis, also known as meningococcus. This bacterium can spread from person to person through close contact, such as coughing, kissing, or sharing items that come into contact with saliva. While there are at least 12 known serogroups of N. meningitidis, serogroups A, B, C, W, and Y are responsible for most cases of meningococcal disease globally.
Serogroup B is a common cause of meningococcal disease in adolescents and young adults in the United States, accounting for approximately one-third of U.S. cases. The disease can manifest as meningitis, an infection of the linings of the brain and spinal cord, or septicemia, a severe blood infection. Even with treatment, meningococcal disease can be fatal in 10% to 15% of infected individuals. Among survivors, about 10% to 20% may experience long-term disabilities, including hearing loss, brain damage, kidney damage, limb loss, or nervous system problems. The symptoms can appear suddenly and worsen rapidly, becoming life-threatening within hours.
Serogroup B requires a specific vaccine, distinct from those protecting against serogroups A, C, W, and Y, due to unique characteristics of its outer membrane capsule. The polysaccharide capsule of serogroup B meningococcus is structurally similar to certain human glycoproteins, which makes it poorly immunogenic, meaning it does not effectively trigger an immune response with traditional polysaccharide-based vaccines. To overcome this, the Serogroup B vaccines were developed using a different approach, focusing on specific proteins found on the bacterial surface to stimulate immunity.
Who Should Get the Vaccine
The Serogroup B meningococcal vaccine is recommended for specific age groups and individuals with increased risk factors. Adolescents and young adults, aged 16 through 23 years, may receive the vaccine for short-term protection against most strains of serogroup B meningococcal disease. The preferred age for vaccination within this group is 16 through 18 years. This recommendation is often based on shared clinical decision-making between the patient and their healthcare provider.
Beyond the general adolescent and young adult population, the vaccine is routinely recommended for specific groups at higher risk of contracting serogroup B meningococcal disease:
- Individuals aged 10 years or older with persistent complement component deficiencies.
- Persons with anatomic or functional asplenia, such as those with sickle cell disease or who have had their spleen removed.
- Microbiologists who regularly work with Neisseria meningitidis isolates.
- Individuals identified during an outbreak of serogroup B meningococcal disease.
Two different Serogroup B meningococcal vaccines are available; the same product should be used for all doses within a series. For healthy adolescents and young adults, a two-dose series is administered, with doses given at 0 and 6 months. For individuals at increased risk due to medical conditions or outbreaks, a three-dose series may be recommended, with doses administered at 0, 1-2, and 6 months. Booster doses may be necessary for those at prolonged increased risk, recommended one year after completing the primary series and then every two to three years thereafter.
What to Expect During Vaccination
The Serogroup B meningococcal vaccine is administered as an injection into the muscle of the upper arm. Common, mild side effects at the injection site include soreness, redness, or swelling. These local reactions are temporary and resolve within a few days.
Beyond the injection site, individuals may experience other common, mild side effects. These include headache, muscle aches, joint pain, fatigue, low-grade fever, chills, or nausea. These systemic reactions are mild to moderate and last for one to three days. Managing these symptoms can involve rest and over-the-counter pain relievers if needed.
While rare, severe allergic reactions can occur after any vaccination. Signs of a severe allergic reaction include hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, or weakness. These reactions happen within minutes to a few hours after vaccination. If any of these symptoms appear, seek immediate medical attention. Healthcare providers are prepared to manage such reactions, and vaccination should always occur in a clinical setting where appropriate medical facilities and trained personnel are available.
Why Vaccination Matters
The Serogroup B meningococcal vaccine works by introducing specific proteins from the Neisseria meningitidis serogroup B bacteria into the body. This harmless exposure prompts the immune system to recognize these proteins as foreign and produce protective antibodies. These antibodies circulate in the bloodstream, preparing the body to fight off a real infection if it encounters the bacteria in the future.
Receiving this vaccine is a proactive step in preventing severe illness. It helps protect individuals from developing meningitis and septicemia caused by serogroup B bacteria, which can progress rapidly and lead to serious health outcomes. By preventing the disease, the vaccine helps avert long-term disabilities, such as hearing loss, brain damage, kidney failure, and limb amputations, which affect a significant portion of survivors.
The vaccine also contributes to broader public health efforts, particularly in settings where outbreaks can occur. While the vaccine’s direct impact on reducing bacterial carriage and transmission is still being studied, preventing individual cases reduces the overall burden of disease. Vaccinating individuals, especially those in close-living environments like college campuses, helps to mitigate the spread of the infection and protects vulnerable populations who may not be able to receive the vaccine themselves.