MENINGOCOCCAL DISEASE AND VACCINATION

CME/CNE October 2011Public Health Unit/Immunisation Advisory Centre, University of Auckland

Meningococcal C disease

Northland DHB disease outbreak and the meningococcal C vaccine

What this presentation covers

• Meningococcal disease and meningitis

• Symptoms and diagnosis

• How you catch it

• Types of meningococcal disease

• Meningococcal disease – around the world

• Protection against meningococcal disease

• Meningococcal vaccine

• Common questions

MENINGOCOCCAL DISEASE• What it is• Symptoms• How you catch it

Meningococcal disease• Caused by Neisseria meningitidis• Frequently rapid onset• Bacteria in the bloodstream interferes with normal

functions, leading to:– Blood poisoning (septicaemia)– Meningitis (Inflammation around the brain)

• There is ~20% risk of permanent damage in survivors• Risk of death around 2-15% of cases– Depends on age, deprivation, early treatment, strain and

presentation

Meningitis is also caused by other bugs

• Meningitis caused by viruses– Usually less severe – Many causes e.g. mumps

• Meningitis caused by bacteria– Usually more severe– Major causes in children

• Hib (immunised against)• Pneumococcal (most common types immunised against)• Meningococcal

Early symptoms and diagnosis

• Symptoms can vary a lot– Unwell, rash,

headache, ‘flu-ish’

• Can change very quickly (hours)

• Important to get rapid treatment– Early antibiotics can kill

the bacteria quickly

Where meningococci lives

• Lives in the nasopharynx (nose and throat)

• Can be in the nose/throat for weeks to months (carriage)

• Usually cleared by your immune system without getting sick

• Occasionally it gets inside the bloodstream and causes the disease

Thomas MG. New Zealand Medical Journal (2004) 117:1200.

How you catch it

• Directly from another person– Commonly carried in the throat and back of nose

(especially teenagers)

• Droplets are spread from the nose and throat

• Disease most often occurs in– Children under 3 years– Adolescents 15 – 18 years

Risk factors for meningococcal disease

• Crowded living conditions, e.g. home or hostel

• Recent respiratory infection

• Exposure to cigarette smoke

• Poor nutrition

• Inherited (genetic) factors

MENINGOCOCCAL DISEASE

• Neisseria meningitidis

Types of meningococcal disease• Major ones are named A, B, C, Y, W-135

• Differ by their exterior sugar coat

• The frequency of different types differs from country to country

• NZ currently major types – B and C

• Is in the community all the time in low numbers– Occasional outbreaks

Men BMen C

Meningococcal around the world

History of meningococcal disease in NZ

‘Auckland ‘A’

NZ ‘B’

Meningococcal disease in NZ

Northland from July 2011

• Recent increase in meningococcal disease– July-Sept

• Nine confirmed cases– Children aged >1 to < 20 years, one elderly

woman– Seven were Group C

• Three deaths (all Group C)

• This constitutes a community outbreak

Rate of meningococcal disease per 100,000 people under 20 years of age July-Sept 2011

Outbreak threshold

Northland meningococcal disease, number of cases in people between 1 and 20 years. 2005 – Sept 2011

Up to September

WHAT PROTECTS AGAINST GETTING MENINGOCOCCAL DISEASE?

• Naturally acquired immunity• Artificially acquired immunity

Antibodies are very important

• Specific antibodies present in the blood can neutralise the meningococci and bring about their destruction

• Many studies have demonstrated that these antibodies are vital to prevent disease occurring

• Three ways to get the antibodies1. Transferred to fetus from mother (temporary)2. Carriage3. Vaccine

What about maternal protection?

• Babies get protection from mother– Mostly through the placenta– Less through breast milk

• Mostly gone by 6 months of age

• Varies depending on woman (needs to have the protection herself in the first place)

Protection by vaccination

• Antigens in the vaccine teach your immune system how to make specific antibodies

• Depending on the vaccine, your immune system creates a memory for how to make those antibodies for a long time

Antibodies against the polysaccharide coat are very important

Macrophages

Meningococci B

Polysaccharide coat

Meningococci C

Antibodies

MENINGOCOCCAL C CONJUGATE VACCINE• Components• Effectiveness• Duration of protection

About the vaccine• Contains the meningococcal ‘C’ sugar

(polysaccharide) attached to a protein • The protein stimulates the immune system to

make antibodies and long-lasting memory• The vaccine also contains a tiny bit of aluminium

salt (0.125mg) which assists in the immune response

• NaCl (salt) • Sterile water

Countries using Meningitec®

• Europe:– UK (on the NIS since 1999), France,

Italy, Germany, Spain, Portugal, Ireland, Greece, Belgium, Switzerland, Hungary, Poland

• Other countries:– Australia (on the NIS since 2003),

Canada, Brazil, Hong Kong, Singapore

Measuring vaccine usefulness

• Immunogenicity- immune response to vaccine

• Efficacy- how well the vaccine did in (clinical) research trials

• Effectiveness- effect of the vaccine on the disease in the real world

Meningococcal C conjugate vaccine

• Immunogenicity/efficacy: 90% to 100%

• Effectivenesse.g. reduction of disease by 95% in vaccinated population (UK)• 1998, 556 cases under 20 years• 2003, 29 cases under 20 years

Laboratory confirmed cases of meningococcal disease in England, 1998 - 2003

Vaccine introduced 1999

Centre for Infections. London: Health Protection Agency Centre for Infections. May 2005.

Duration of protection

• Several years in younger children

• Longer with older children, at least five years

• If the disease returns in the community can vaccinate to boost protection

Vaccination is important for both individual protection and community immunity (via reducing carriage)

Vaccine reactions

Toddlers Older age groups

Any pain 21% 63%

Pain interfered with movement

9% 7%

Redness ≥ 2.5cm 2% 13%

Swelling ≥ 2.5cm 2% 7%

Fever ≥ 38.0 °C 30% 1%

Fever ≥ 39.1°C 4% 0%

Sleepy 20% 3%

Headache 12% (secondary school)

Selected results from combined clinical trials

Ongoing safety monitoring shows a very rare rate (less than 0.01%) for serious adverse reactions

Serious events

• Fainting (a reaction to having an injection)

• Anaphylactic reaction – extremely rare, 1/500,000 doses

• Other adverse events occurring after receipt of this vaccine have been at the same rates as people who have not received the vaccine

Andrews N, Stowe J, Miller E, Taylor B. Post-Licensure Safety of the Meningococcal Group C Conjugate Vaccine. Human vaccines. 2007;3(2):59-63.

For the Northland outbreak

• 1 dose for all 1 year to under 20 years– intramuscular in the upper arm (or leg in young infants

not yet weight bearing, usually under 15 months)

• Why not give to infants under 1 year– No disease currently in under ones– Infants usually don’t carry it in their throat– Vaccine not effective for under ones in a single dose– Infants should get protection from less people carrying

it

Summary: Key points• There are many different sorts of meningitis• There are different sorts of meningococcal disease– Be very aware of signs and ask for help early

• There is currently an outbreak of Group C in Northland• There is a vaccine that is very effective in most children– International vaccine, used widely– Single dose in children 1 – 19 years

• This vaccine works both for protection to the individual and reduces the spread in the whole community by reducing carriage in the throat

• This vaccine has an excellent safety profile

ANY QUESTIONS

Contacts

• 0800 IMMUNE (466863)– Free phone line staffed by registered nurses with

specialist expertise in vaccines and vaccine preventable diseases

– Backed up by doctors and scientists

• www.immune.org.nz– University of Auckland, Immunisation Advisory

Centre website– Lots of links to other websites