The vaccine is not licensed for children under 8 weeks old because there is not enough information about how well the vaccine works in this age group.
How will this vaccine be scheduled as a routine immunisation?
The JCVI recommended that the vaccine should be administered to babies at 2, 4 and 12 months of age (2 primary doses in infancy and 1 booster dose at 12 months). Although the vaccine is licensed to be given to 2 month olds as 3 primary doses in infancy with 1 booster dose, the JCVI considered 2 primary doses to be sufficient based on evidence from vaccine trials.
Is the vaccine safe?
As with all drugs, vaccines can cause side effects. Vaccine side effects may include soreness/redness/swelling or hardness of skin at the injection site, fever, lack of appetite, muscle aches, irritability, sleepiness and rashes. Almost 8,000 people, including more than 5000 infants and toddlers, have had the new MenB vaccine during clinical trials[1-3, 6-8]. Results from these trials have shown that Bexsero® has a good safety profile. A review of the data by the European Commission resulted in vaccine licensure in January 2013 on the basis of the benefits of the vaccine outweighing the risks.
Can Bexsero® be given at the same time as other routine vaccines?
Yes. The side effects seen when Bexsero® is given with other vaccines in the routine childhood schedule are the same as those commonly seen with vaccines in general. This is also true when the vaccine is given at the same time as hepatitis B and varicella vaccines.
Fever is more common in babies when Bexsero® is given alongside other vaccines although taking paracetamol after getting vaccinated (or at the same time) reduces the likelihood and severity of fever without affecting the immune response to any of the vaccines.
What are the active ingredients in the vaccine?
The active ingredients that equip our immune system to fight MenB bacteria include four main components of meningococcal bacteria. Three of them are proteins found on the surface of the bacteria:
• Factor H Binding Protein (fHbp)
• Neisseria Heparin Binding Antigen (NHBA)
• Neisserial Adhesin A (NadA)
These three components help meningococcal bacteria invade and survive within the human body. In vaccinated people, the immune system can recognise and ‘neutralise’ these components, so the bacteria cannot make them ill.
The final ingredient is the New Zealand MenB Vaccine (MenZB) derived from the New Zealand outbreak strain of MenB (strain NZ 98/254).
All of these components have been processed and inactivated and are not part of any living bacteria, but can still stimulate the immune system.
Are there any safety reasons not to have the vaccine? What about allergies?
People who have previously had an anaphylactic reaction to any of the vaccine components should not get the vaccine. In addition to the active components already mentioned, the vaccine is composed of sodium hydroxide, histidine, sucrose and water.
Anaphylaxis to current vaccines is very rare and is estimated to occur in one in a million doses given, although a recent study found no reports of anaphylaxis following more than 5 million preschool and infant immunisations over an entire year in the UK and Ireland.
People with severe immune system problems cannot have live vaccines, but the new MenB vaccine is not live. Food allergies are not a reason to avoid vaccination, except people with egg allergies who may need to avoid some flu vaccines. People often worry that eczema, asthma, epilepsy and a family history of reactions to vaccinations are a reason to avoid vaccinations, but this is not true.
Why has it been so difficult to develop a MenB vaccine?
Meningitis vaccines developed up to now have been made from a fragment of the bacterial sugar coat. When we are vaccinated our immune system learns to recognise and attack this sugar as a ‘foreign invader’ by producing antibodies which help us destroy bacteria if we come into contact with one with the same sugar coat. However, the sugar coat of MenB bacteria does not trigger an immune response, because it looks like developing human cells. This means that the immune system does not recognise it as a foreign invader, and this protects it from attack. So using the sugar coat just does not work for MenB vaccine development.
The search for a MenB vaccine has focused on other elements of the surface of MenB bacteria but it has been very difficult to find elements which are both ‘visible’ to the immune system and present in every MenB strain. Even elements that are usually present are extremely variable, so the immune response against a vaccine made from one kind of MenB may not be capable of killing all the different MenB strains.
Are there other MenB vaccines?
Vaccines covering just one strain of MenB have been used successfully in New Zealand and Cuba to control epidemics in those countries caused by particular MenB strains. Our research has helped to show that neither of these vaccines would cover the majority of MenB infection in the UK and the rest of Europe. This new MenB vaccine, produced by Novartis, is the first one designed to cover different strains of meningococcal B infection around the world. Another MenB vaccine is also being developed by Pfizer, but is not yet licensed.
Why isn’t the MenB vaccine expected to cover 100% of cases?It is impossible to be certain about the precise extent of coverage. The MenB vaccine is based on four main protein components found on the bacterial surface across most of the hundreds of different MenB strains. However, the structure of each protein can vary a lot and some bugs have more of a particular protein on their surface than other bugs do. The antibodies we produce after we’ve been vaccinated may not be able to recognise a protein carried on the surface of an invading MenB bug if its structure is a bit different to the protein in the vaccine, or if there is not very much protein to latch onto. If our antibodies cannot attach to an invading bug, our immune system will be unable to destroy it.
However, in addition to these main four protein components, other ingredients that are part of the vaccine formulation may also produce immunity. This may add to the coverage predicted for the four main vaccine components.