Meningococcal B Vaccine

Details

What is Meningococcal infection?

Meningococcal infection is a life-threatening and communicable disease caused by the bacteria Neisseria meningitidis, or meningococcus. There are 13 known serogroups, of which 6 are the major causes of clinical cases (MenA, B, C, X, W135, and Y). Although less common, severe illness may result in meningitis (infection of the lining of the brain and spinal cord) and septicaemia (infection of the blood). In Hong Kong, 10-20 children are diagnosed each year sporadically, with a death rate of around 20%. Even when it is treated, about 10-20% will suffer disabilities such as hearing loss, brain damage, kidney damage, loss of limbs, nervous system problems, or severe scars from skin grafts.

Route of transmission and preventive measure

The disease is mainly transmitted by direct contact through respiratory secretions, including droplets from the nose and throat, from infected persons. The incubation period varies from 2-10 days, and is commonly 3-4 days. Meningococcal infection is a preventable disease. There are 2 types of meningococcal vaccines available in Hong Kong. One cover meningitis ACWY and the other cover meningitis B. Both vaccines are not yet included in the Hong Kong Childhood Immunisation Programme (HKCIP). The number of reported cases in China has steadily declined since meningococcal A and C vaccine was introduced to the Expanded Programme on Immunisation (EPI) since 2008, with the proportion of MenA and C cases began to decline and MenB to rise. In 2018, 50% of meningococcal infection in Hong Kong was caused by serogroup B, followed by 20%, 20% and 10% of serogroup C, Y and W-135. Since meningitis B vaccine was not available in Hong Kong until Jun, 2019, the vaccine most people may have received when they were younger covered meningitis ACWY only.

Who should get the vaccine?

Anyone can get meningococcal disease but certain people are at increased risk, including:

• Children below 5 years, especially infants
• Adolescent
• Patient with immunodeficiency or chronic illness
• Travellers to areas where meningococcal disease is common, or are known to experience epidemic meningococcal disease as announced by authorities, such as Africa, Saudi Arabia, North America or Europe

We recommend the vaccines for all children beyond 2 months due to the serious and sporadic nature of meningococcal infection.

What are the common side effects?

Common side effects may include soreness, redness, or swelling where the shot is given. Headache, fatigue, diarrhea, irritability, loss of appetite or fever may also occur within 24 hours after getting the vaccine. These reactions will occur in around 5% of people who receive the vaccine. These reactions are mild and generally last 1 to 2 days.