Vaccines for meningitis: How they work, who they are for, side effects

 Key takeaways

• There are available vaccines for meningitis, such as MenACWY and MenB vaccines. 
• Meningitis vaccines contain meningitis-causing bacteria in small quantities and stimulate the production of antibodies. The antibodies protect against bacterial meningitis by fighting the meningitis-causing bacteria when they enter the body in larger quantities.
• Anyone can receive a meningitis vaccine shot, especially those living in meningitis-prone regions. Speak with your doctor to guide you on the vaccine type that is best suited for your age group. 

Meningitis is an inflammation of the meninges, which are membranes that cover the brain and spinal cord. The meninges consist of three layers:

• Dura matter, 
• Arachnoid matter and 
• Pia matter. 

These layers provide a supportive framework for the brain. They also protect the central nervous system from damage. Infection of these layers of the meninges causes a type of inflammation, medically referred to as meningitis.

Meningitis affects more than 2.5 million people globally each year.

Bacteria, viruses, and fungi are some of the microorganisms that infect the meninges. According to the World Health Organization (WHO), bacterial meningitis has the highest global burden compared with the burden of viral and fungal meningitis. This means bacterial meningitis causes more severe symptoms.

On the other hand, viral meningitis is common but causes milder symptoms, while fungal meningitis is rare.

Reading further, we will discuss the available vaccines for meningitis, how they work, and who they are meant for.

 What are the available vaccines for meningitis?

Meningitis-causing bacteria have different strains known as serotypes or serogroups. Serotypes are groups of bacteria with similar features and characteristics. Vaccines fight these serotypes of bacteria.

Meningitis vaccines are active against meningococcal, pneumococcal, and Hib meningitis. Meningococcal meningitis, caused by Neisseria meningitidis, is the most frequent type of meningitis. It causes meningitis outbreaks, particularly in the northern parts of Nigeria, between November and June.

Neisseria meningitidis has 5 main serotypes that cause meningitis: A, B, C, W, and Y.

There are 2 types of vaccines against these serotypes. The two vaccines are also readily available (in the United States) for meningitis.

They are:

• Meningococcal conjugate or MenACWY vaccine (Menactra, Menveo, and MenQuadfi) 
• Serogroup B meningococcal or MenB vaccines (Bexsero and Trumenba)

MenACWY is active against serotypes A, C, W, and Y. MenB is active against only serotype B.

There are also other types of vaccines, including: 

• Pneumococcal vaccines 
• Hib/MenC vaccines
• MMR vaccines, and 
• 6-in-1 vaccines. 

 How do meningitis vaccines work?

Vaccines are attenuated, live forms of an organism. This means they contain weakened or inactive parts of a particular organism. When administered into the body, they trigger an immune response. This leads to the production of antibodies to fight the real microorganism. 

The quantity of the weakened organism is so little that it doesn’t cause the disease. But it makes the immune system ready to fight the microorganisms when they enter the body in large numbers.

 Are meningitis vaccines effective?

The WHO states that vaccines are the best protection against bacterial meningitis. And because of the severity of bacterial meningitis, its prevention is better than treatment. 

A 2017 study showed 66%-100% effectiveness with meningococcal vaccines against meningitis. However, there’s no single vaccine that works for all the serotypes of the organism.

 Who is the meningitis vaccine for?

Because meningitis can infect anyone, the vaccines are suitable for people of all ages. But, the vaccines vary depending on the patient’s age and body deficiencies. 

Different age groups are likely to suffer from meningitis caused by a particular bacteria.

• Newborn babies are at the highest risk of Group B streptococcus.
• Younger children are at the greatest risk from meningococcus, pneumococcus, and Haemophilus influenzae.
• Adolescents and young adults are at the most risk from meningococcus. 
• The elderly are at the highest risk of pneumococcus.

However, If you fall into any of the following categories, the WHO particularly recommends you take the vaccines:

• Newborn babies. They are at risk of infection because their immune systems are still developing.
• People living in Sub-Saharan Africa. The region has the highest burden of bacterial meningitis infection.
• People who live close to one another because of the risk of easy spread of the disease. Places like refugee camps, school hostels, and military environments.
• People who have immune deficiencies, such as HIV patients, cancer patients, and active & passive smokers.
• Scientists working on Neisseria meningitidis samples from infected patients.
• People who have a rare type of disorder called complement component deficiency. This condition weakens their immune system.
• People who take a type of medicine called complement inhibitors. This also weakens the immune system. 
• People with damaged spleens or whose spleens have been removed. 
• People with sickle cell.

 Meningitis vaccine for babies and children

For babies ages 2 months to 10 years, the Centers for Disease Control (CDC) recommends the MenACWY meningitis vaccine if they 

• Have complement component deficiency (immune system disorders that cause different symptoms depending on the specific complement protein a person lacks)
• Take complement inhibitors
• Have a damaged spleen or the spleen has been removed, or have sickle cell anemia. 
• Have HIV
• Live in or travel to countries where Serotypes A, C, W, and Y are common. 
• Are part of a population at increased risk because of Serotypes A, C, W, and Y meningococcal outbreak.

For children 10 years of age and older, they recommend MenB if they:

• Have complement component deficiency 
• Take complement inhibitors
• Have a damaged spleen, or the spleen has been removed, or have sickle cell anemia
• Are part of a population at increased risk of the Serotype B meningococcal outbreak.

Talk to your doctor to know what's best for your baby and if your baby needs a booster shot.

 Meningitis vaccine for preteens and teens

Preteens between 11 and 12 years old will receive the MenACWY vaccine, with a booster shot at 16 years old.

For teens between 16 and 18 years old, they should get the MenB vaccine.

Any teen can also get the MenB vaccine if they:

• Have a complement component deficiency
• Take a medicine called a complement inhibitor
• Have a damaged spleen or sickle cell problem
• Are part of a population at risk of serogroup B meningococcal outbreak.

 Meningitis for adults

Adults can take the ManACWY if they:

• Have complement component deficiency 
• Take complement inhibitors
• Have a damaged spleen, or the spleen has been removed, or have sickle cell anemia
• Are HIV patients 
• Live or travel to countries where Serotypes A, C, W, and Y are common
• Are part of a population at increased risk because of Serotype A, C, W, and Y meningitis outbreaks.
• Are military recruits
• Are microbiologists exposed to Neisseria meningitidis
• Are not up to date with their vaccinations, and our first-year students living in a hostel.

Adults can also take MenB if they:

• Have complement component deficiency 
• Take complement inhibitors
• Have a damaged spleen, or the spleen has been removed, or have sickle cell anemia
• Are part of a population at increased risk because of Serotype A, C, W, and Y meningitis outbreaks.
• Are microbiologists regularly exposed to Neisseria meningitidis 

Still, talk to your doctor to know what's best for you, and when you need your MenB or MenACWY booster shots.

 Who is the meningitis vaccine not recommended for?

The Meningitis vaccine is not recommended for some people. This is because of the adverse drug reactions that may happen upon administration. They include:

• Pregnant people, and nursing (breastfeeding) mothers.
• If you don’t feel well enough, e.g., if you have a cold. Wait until you recover before you take the vaccine.
• If you’ve had a severe allergic reaction to the previous administration of the vaccine. You could be allergic to any of the vaccine’s ingredients. 

 Possible side effects of meningitis vaccines

Meningitis vaccines are safe but might have some mild side effects. These side effects could be due to the method of administration. And not necessarily the vaccine itself. 

The possible side effects include:

For MenACWY:

• Redness of the site of administration
• Headache and Fever
• Pain and fatigue

For MenB:

• Soreness
• Headache and Fatigue
• Nausea and diarrhea
• Fever or chills
• Muscle or joint pain

 Are meningitis vaccines available in Nigeria?

According to the Nigeria Center for Disease Control (NCDC), meningitis caused by Serogroups A and C has been a problem for the past two decades. There were Serogroup A epidemics in 1996, 2003, 2008, & 2009. And by 2010, WHO and the NCDC had introduced the Serogroup A Conjugate vaccine to curb the menace. 

From 2011 to 2022, the agency vaccinated more than 100 million Nigerians using ManA conjugate vaccines. In 2019, Nigeria included the vaccine in its routine immunization schedule.

There was also a similar outbreak of Serogroup C in 2013 & 2014 in some Northwestern states. By 2017, WHO and her partners had sent more than 500,000 doses of meningitis C vaccines to Nigeria.

In 2023, bivalent (A & C), trivalent (A, C & W), and tetravalent (A, C, Y & W) meningococcal vaccines are being used for vaccination. 

 Closing

Meningitis is one of the most lethal infections because it affects the brain. But the vaccines are very effective against the disease. There are vaccines for different age groups.

So, if you're going to travel to a meningitis-endemic area, talk to your doctor to determine your vaccination status.