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![IMMUNISATION
• Two FORMS of immunisation
– Passive immunisation
• Natural passive immunisation = transplacental or colostral
transfer of antibodies from the mother to the baby
• Artificial passive immunisation = intramuscular inoculation of
immunolobulin [IG])
– Active immunisation
• Natural - following resolution of natural infection
• Artificial - direct inoculation of a vaccine, the process is called
vaccination
• Important to note that:
– Immunisation is NOT synonymous to vaccination
– Vaccination is another form of immunisation
– Vaccination ONLY involves the use of a vaccine
Science of controlling and preventing infectious diseases](https://image.slidesharecdn.com/vaccination-250423195321-f63e3740/85/Vaccination-program-and-prevention-in-zimbabwe-pptx-19-320.jpg)
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Vaccination program and prevention in zimbabwe.pptx
- 1. Vaccinations prevention of childhoodillness ZEPI (Zimbabwe expanded Program on immunization) Prof FZ Gumbo
- 2. • Disclosure : Someslides borrowed from Prof Gumbo’s lecture on ZEPI
- 3. Refer to Immunisationagenda 2030
- 4. Deaths under 5years (Preventable)
- 5. What diseases dovaccines prevent ? 1. Diphtheria 2. Hepatitis B 3. Measles 4. Meningitis (HiB) 5. Pneumonia (PCV) 6. Polio 7. Pertussis 8. Rotavirus 9. Rubella 10. Tetanus 11. Typhoid 12. Cervical cancer 1. Rabies 2. Varicella 3. Yellow fever 4. Cholera 5. Mumps 6. Influenza 7. Ebola 8. Malaria 9. Japanese encephalitis 10. HIV 11. COVID-19
- 6.
- 7. Outline • Key Definitions –Immunisation vs. Vaccination – Objectives of vaccination • Vaccines – Definition of a vaccine – Properties of an ideal vaccine – Overview of types and examples of vaccines – Components of different vaccines – Technologies applied to produce vaccines – Examples of vaccines • Presentations of Vaccines – Monovalent vs. Polyvalent (combination) vaccines – Liquid – vs. Freeze-dried vaccines (Measles, yellow fever, HiB and BCG)
- 8. How vaccines work? •Vaccines use the knowledge of the immune system to mimic infection, generate immunologic memory, and prepare the body for future infections. • An ideal vaccine – provides lifelong immunity from disease – protects against multiple strains of the same disease – it is safe, inexpensive, stable – preferably not administered via injection (not always possible)
- 9. • The mainobjective of the vaccination schedule is to protect individuals from disease by providing immunity before they acquire disease. • To understand how vaccines provide protection, it is important to understand the essential components that compose the immune system and how the immune system generates a response to perceived pathogens.
- 10. OVERVIEW OF THEIMMUNE SYSTEM Primitive Physical, physiological and cellular Sophisticated Highly specific
- 11. There are 2types of responses to vaccine antigens T-cell–dependent responses and T-cell–independent responses. • Vaccine antigen is critical in determining these responses and, therefore, its immunogenicity. • Protein antigen, such as a live attenuated virus or a protein such as hepatitis A vaccine, activates both B cells (that produce antibodies) and T cells. • This is called a T-cell– dependent response T-cell–independent response • Polysaccharide vaccines such as 23-valent pneumococcal vaccine antigens directly trigger B cells, resulting in the production of antibodies by B cells without generation of immune memory. • This is called a T-cell– independent response because it does not require T cells to mediate its action.
- 12.
- 13. T cell dependentvaccine Live viral •MMR, Rota, Oral Polio Live Bacterial •BCG Killed Virus •Inactivate Polio virus Killed Bacterial •Whole cell Pertusis Conjugated •Pneumococcal , HiB Protein Viral • Hep B, HPV Protein Bacterial • Acellular Pertusis, Tetanus, Diphtheria
- 14. T cell independentVaccines Polysaccharide vaccines Salmonell a Typhoid Meningoc occal Pneumoc occal PCV 23
- 15. • Vaccines containthe same antigens (or parts of antigens) that cause diseases. For example, measles vaccine contains measles virus. • But the antigens in vaccines are either killed, or weakened to the point that they don’t cause disease. • However, they are strong enough to make the immune system produce antibodies that lead to immunity. • In other words, a vaccine is a safer substitute for a child’s first exposure to a disease. • The child gets protection without having to get sick. Through vaccination, children can develop immunity without suffering from the actual diseases that vaccines prevent.
- 16. More Facts • Newbornbabies are immune to many diseases because they have antibodies they got from their mothers. However, this immunity goes away during the first year of life. • If an unvaccinated child is exposed to a disease germ, the child’s body may not be strong enough to fight the disease. • Before vaccines, many children died from diseases that vaccines now prevent, such as whooping cough, measles, and polio. • Those same germs exist today, but because babies are protected by vaccines, we don’t see these diseases nearly as often.
- 17. Immunizing individual childrenalso helps to protect the health of our community, especially those people who cannot be immunized (children who are too young to be vaccinated, or those who can’t receive certain vaccines for medical reasons), and the small proportion of people who don’t respond to a particular vaccine (herd immunity) . Diseases that are vaccine-preventable have a costly impact, resulting in doctor’s visits, hospitalizations, and premature deaths. Sick children can also cause parents to lose time from work.
- 18. The main objectiveof the vaccination schedule • is to protect individuals from disease by providing immunity before they acquire disease. • Long-term immunity is important in determining the effectiveness of the immunization schedule. • Important factors in determining the immunization schedule: • Short-term protection • local prevalence and incidence • disease epidemiology • safety • programmatic aspects (including number of doses, funding, organization, and cost)
- 19. IMMUNISATION • Two FORMSof immunisation – Passive immunisation • Natural passive immunisation = transplacental or colostral transfer of antibodies from the mother to the baby • Artificial passive immunisation = intramuscular inoculation of immunolobulin [IG]) – Active immunisation • Natural - following resolution of natural infection • Artificial - direct inoculation of a vaccine, the process is called vaccination • Important to note that: – Immunisation is NOT synonymous to vaccination – Vaccination is another form of immunisation – Vaccination ONLY involves the use of a vaccine Science of controlling and preventing infectious diseases
- 20. WHAT IS AVACCINE? Modified from Canadian residents vaccine training program A suspension of live attenuated (replicating) or killed (non-replicating) microorganisms* or subunit / fractions* (non-replicating) thereof (i.e. purified protein subunits, polysaccharides, or split virions) that are administered (IM, SC, ID, Mucosal, or Oral), for the prevention or treatment of infectious diseases *subunits or fractions from virus, bacterium, fungus, or parasite (Antigen) Vaccines can be classified using different parameters
- 21. VACCINES: TYPOLOGY &EXAMPLES REPLICATING VACCINES (Live attenuated) - Oral Polio Vaccine (Sabin) - BCG - Bacillus Calmette-Guerin - Measles - Yellow Fever and Rotavirus - Mumps, Rubella, Varicella, oral typhoid, etc NON-REPLICATING VACCINES (Killed or Inactivated) Whole-cell vaccine - IPV (Salk) - Whole-cell pertussis (wP) - hepatitis A, Influenza, rabies, cholera, etc Subunit or Fractional vaccines - Hepatitis B - plasma or recombinant - Diphtheria and tetanus toxoids - Haemophilus influenzae type b - Acellular pertussis (aP), polysaccharides (MenACWY, S. Typhi Vi) - conjugated polysaccharides (Hib, pneu, men) ..) - Influenza (subunit or split virion), Human Papilloma virus, etc
- 23. PROPERTIES OF ANIDEAL VACCINE • Safe – revert to virulence, toxicity of killed vaccine • Immunogenic – Host responds with appropriate immunity • Effective duration • Non-immunosuppressive • Cost vs benefit – monetary and risk with use – recipient and population – e.g. killed cells inexpensive – low benefits bec of S/E • Relative risk of vaccine vs infection
- 24. History of theNational Immunization Programme in Zimbabwe • The EPI was established in 1974 through the resolution WHA27.57 to build on the success of the global smallpox eradication programme. • The Zimbabwe expanded program on immunization, (ZEPI) established as a component of primary health care at independence in 1980 • Focus on building a sustainable immunization system to protect children against common vaccine-preventable diseases: Initially 6 vaccines: diphtheria, tetanus, pertussis, poliomyelitis, TB, and measles. Other vaccines have since been added: HIB, HBV, PCV, ROTA, MR. HPV, Typhoid (TCV) Pipeline: Hep B birth dose Immunization of pregnant women and WCBA: preventing maternal tetanus and newborn infants from neonatal tetanus.
- 25. Tuberculosis • Bacterial infection- mycobacteriumtuberculosis • Droplet infection, S & S varies • Vaccine –Bacille Caimette Guerin (BCG),many strains • Live attenuated, freeze dried • Reduces morbidity and mortality from TB in infants, meningitis, miliary TB • At birth, intradermal Right arm-insertion of deltoid muscle
- 26. BCG – Intradermalvaccination
- 27. • acute diseasecaused by exotoxin producing Corynebacterium diphtheriae • highly contagious disease • humans are the only source of infection • transmitted via respiratory aspiration and exudate from infected skin lesions1 • typically a disease of upper respiratory tract mortality is highest in young and elderly1,2 adapted from Diphtheria vaccine, WER N3 Jan 20, 2006; 81 pp.24-32 Diphtheria
- 28. Diphtheria disease course recovery deathin 5–10% of cases exposure initial symptoms ● irritability ● lack of activity ● patches of exudate appear in pharynx acute symptoms ● thick, grey membrane forms, covering pharynx ● cervical lymph nodes become enlarged and tender ● inflammation and oedema of soft tissues surrounding pharynx giving classical ‘bull-neck’ appearance ● rapid pulse membrane sloughs off and acute symptoms disappear incubation (2–5 days) 2–3 days 7 days complications 1. Wharton & Vitek 2004, In: Vaccines (Ch 13) 2. CDC Pink Book. 2005:55–64
- 29. Diphtheria prevention (Inactivated Toxin) • vaccines basedon diphtheria toxoid (modified toxin) inducing protective anti-diphtheria toxin antibodies • DTPw part of EPI since 1974; from 1980-2000 >90% reduction in the number of reported cases • following priming (3 im doses generally at 6,10,14 weeks) protection lasts for +/- 10 years; boosters at 2nd year and to 4-6 year olds if resources permit • immunity maintenance through exposure to toxigenic C. diphtheriae in areas of low vaccination coverage; if coverage is high, because of low level of natural boosting there is a need for booster vaccinations adapted from Diphtheria vaccine, WER N3 Jan 20, 2006; 81 pp.24-32
- 30. Etiology – Characteristics TbbTtbbtteTttttttt •Infectious bacterial disease caused due to toxin produced by anaerobic bacterium (Clostridium tetani) – Highly potent neurotoxin (tetanospasmin) – It is a single polypeptide chain – Neurotropic • Extremely potent – Estimated human lethal dose is 2.5 ng/kg – Once inside the neuron it cannot be neutralized by tetanus antotoxin • Disease may affect any age group – Mainly newborns in developing countries ; unclean delivery & Poor post natal hygiene ( poor cord care practices) – Maternal Tetanus –unsafe abortion; unclean delivery – Elderly Tetanus
- 31. Neonatal tetanus - Disease •Initial sign – clenching of jaws (lock-jaw) • Spasm of facial muscles – risus sardonicus • Gradual spasm of all muscles, arching back, clenched fists, followed by convulsions • Spasm of breathing muscles lead to suffocation • Infection of umbilical stump • Incubation period: 1 day – 3 months (normally 3 days to 3 weeks) • Intense disease for 4 weeks, then subsides • Mortality directly proportional to the quality of care given (eg ventilation) 10–70% but with best care, age and general health of the patient mortality 10-20%
- 32. TT vaccine presentations Single toxoid(TT) Combined with diphtheria toxoid (DT) or low- dose diphtheria toxoid (Td) Combined with diphtheria and pertussis vaccines (DTwP, DTaP, dTaP or dTaP)
- 33. Tetanus Toxoid vaccine I Interval betweendoses is 4 weeks • For perinataly infected children response to TT was adequate for 2 years of life • In HIV infected adults ab response is less than non HIV infected adults but concentration of ab is substantial Longer interval may provide increased magnitude and duration of protection (not reason to delay schedule) Efficacy in most clinical trials is 80-100% Response to vaccination is similar between malaria infected pregnant mothers and non malaria infected adults Antibody response to TT in children with AIDS is impaired like other vaccines
- 34. Pertussis Bordetella pertussis, highlyinfectious Severe cough often with whoop, cyanosis and vomiting-6-8wks Young infants-apnoeic spells 3 stages; catarrhal, paroxysmal, convalescent Treatment erythromycin Pentavalent and 18months booster. 5years not given
- 35. Pertussis disease course 1.CDC Pink Book. 2005:75–88 2. Linnemann Jr 2003, In: Oxford Textbook of Medicine (Ch 7.11.14) 3. Mortimer Adv Pediatr Infect Dis1990;5:1–33 incubation period (7–10 days) convalescence complications infection paroxysmal stage initial catarrhal stage 1–2 weeks 1–6 weeks recovery (99%) death (0.04–1%) long-lasting, irritating cough spasms of coughing ending with a “whoop” fever, malaise broncho- pneumonia hemorrhages brain damage
- 36. 1. CDC PinkBook. 2005:75–88 2. Mortimer Adv Pediatr Infect Dis 1990;5:1–33 3. Wortis et al. Pediatrics 1996;97:607–12 Pertussis complications • secondary respiratory infections (e.g. pneumonia)1,2 • consequences of severe coughing; conjunctivitis, nose bleeds, hernias, atelectasia … • CNS (from minor convulsions to coma/ permanent brain damage) • 87% deaths occur in infants aged <1 year3
- 37. Adverse events associated with whole cell Pertussis vaccination (wP) • Redness,swelling and pain at injection site • High temperature • Fretfulness, drowsiness, anorexia, vomiting and persistent crying • Febrile convulsions • Collapse • Pertussis vaccine encephalopathy • SIDS
- 38. Contraindications to wP vaccination Neurologicillness due to vaccination Persistent unconsolable screaming for 3 or more hours Hypotonic hyporesponsive episode Temperature of 40.5 C or > Anaphylaxis Febrile illness - defer Evolving neurologic disease - defer Acellular pertussis (aP) prefered
- 39. Poliomyelitis Viral, faeco- oraltransmission Fever followed by AFP Incubation period 8-12days Paralytic occurs 0.1% Suspected AFPs - 2 stool specimens 24-48hrs apart Supportive management
- 40. Some Key Differences IPVOPV Immunity humoral intestinal/humoral Cost US dollars US cents Delivery injection oral Herd immunity limited substantial
- 41. Polio vaccine bOPV @ 6wks,10wks,18mo IPV @ 14 wks At least one dose of IPV must be introduced in addition to bOPV to protect against type 2 poliovirus and boost population immunity. Switch from tOPV to bOPV will reduce risk of VAPV and increase protection from type 1 & 3 Both IPV & OPV ensures protection from polio. OPV given orally provides protection in the mouth, in intestines and then in blood. IPV further strengthens the protection given by OPV and helps increase the overall protection against polio bOPV – bilvalent tOPV – trivalent IPV - inactivated
- 42. Measles Disease • Acute viraldisease - Highly infectious • Transmission - via respiratory secretions or aerosols • Viral replication & dissemination of virus into different organs • Classic manifestations (Fever, Maculopapular rash, the 3C: Cough, Coryza, Conjunctivitis; Kopliks spots) • Mortality rate - 0.1 – 10%;Up to 30% in humanitarian emergencies (Risk increases with age, malnutrition, other cause of impaired immunity)
- 43. Clinical course ofmeasles Incubation period ( 7–18 days before rash) 18 days before rash Exposure happened the earliest 18 days before rash 4 days before rash Is the probable start of infectiousness Prodrome (about 4 days) -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 4 days after rash Is the probable end of infectiousness Rash (about 4–8 days) rash The case is identified here
- 44. - Live attenuatedvirus vaccine - Lifelong immunity - Efficacy: Age (Months) Seroconversion* (%) 6 50% 9 85% (Routine EPI dose) 12 90% 15 95% (eg., SIA or NIDs dose) Seroconversion is the proportion of people who develop protective antibodies against measles virus after being vaccinated. Measles Vaccine: Characteristics
- 45. Contraindications and Precautions Measles vaccinations (live attenuated) •High fever (postpone) • Previous Febrile convulsions not a contraindication • Severe allergic reactions to prior dose of vaccine or vaccine component • Neomycin, Gelatin most allergenic • Severe Immunosuppression (CD4<200) • Immunoglobulin transfusion • Temporary contraindications • Pregnancy and breast feeding • Moderate or severe illness • Recent receipt of blood product • Egg allergy(monitor) • Has been rarely associated with Sclerosing Subacute Panencephalitis • Thrombocytopenia (monitor)
- 46. Hepatitis B • HBV • Transmission-vertical,perinatal, horizontal,parenteral and sexual • Long-term HCC and Cirrhosis particularly for vertical transmission • Plasma derived and DNA recombinant vaccine • 90% efficacy • For ZEPI part of Pentavalent - birth dose still under consideration
- 47. HPV (Human Papilloma Virus) • Pastdecade, two prophylactic HPV vaccines, – Cervarix® - bivalent – Gardasil®) both the quadri- valent and 9 – valent • licensed globally • for the prevention of infection and precancerous cervical lesions caused by HPV (Meites, 2016).
- 48. HPV • Clinical trialshave shown that a three dose HPV vaccination schedule is 100% efficacious in preventing high grade cervical intraepithelial neoplasia (CIN3+) and adenocarcinoma in situ (AIS) in HPV naive females (Munoz, 2010)(Apter, 2015). • Concurrently, this preventive treatment was also shown to have an acceptable safety profile and sustained immunogenicity
- 49. Adverse Events Following HPV Immunization • 53 parents,5.6 % reported [Beitbridge 7.5%, Marondera 3.7%) – Dizziness, fever, headache, nausea, vomiting, fatigue, rash and swelling, pain at injection site • Mostly (57% BB, 72% MDA) were mild and/or shortlived…needed no treatment, or gave pain killer,
- 50. Haemophilus influenzae type B Subunit (purified antigen) •Important cause of bacterial meningitis in childhood • Pneumonia, epiglotitis, arthritis, otitis media, septicemia etc • Conjugate vaccine • Combination vaccine (Pentavalent) • Efficacy 95-100% • Herd immunity
- 51. Rotavirus • Leading causeof severe gastroenteritis in infants and young children • Seasonal -2 peaks in Zimbabwe • Two vaccines, Rotarix(2 doses) and Rotateq( 3 doses) • Zimbabwe use Rotarix oral vaccine at 6 weeks and 10weeks • Contraindicated after 32 weeks-Intusussception
- 52. Pneumococcal • Diseases causedby Streptococcus pneumoniae are a major public health problem worldwide. • Pnemonia, meningitis, bacteraemia, otitis media, sinusitis and bronchitis • Types of vaccine……
- 53. Pneumococcal Disease(s) Prevented by theVaccine Pneumococcal diseases, severe (meningitis, pneumonia, other invasive diseases) and mild (otitis media, sinusitis, bronchitis) caused by vaccine serotypes. Type of Vaccine Polysaccharide-protein conjugate vaccine: vaccine does not contain any live bacteria. The PCV13 vaccine covers 13 serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) and is available as a liquid presentation. Dose, Route and Site of Administration 0.5ml by intramuscular (IM) injection into the antero lateral aspect of the left mid- thigh. Presentation A single dose vial.
- 54. ROUTES OF ADMINISTRATION subcutaneousintramuscular intradermal oral OPV Rotavirus Measles HBV DPT MMR IPV Etc BCG
- 56. Immunization schedule Name ofVaccine Age of Administration Route BCG At birth Intradermal deltoid muscle right arm OPV 1 Pentavalent 1 PCV 1 Rotavirus 1 6 weeks Oral Intramuscular antero-lateral aspect of the right mid-thigh Intramuscular antero-lateral aspect of the left mid- thigh Oral OPV 2 Pentavalent 2 PCV 2 Rotavirus 2 10 weeks Oral Intramuscular antero-lateral aspect of the right mid-thigh Intramuscular antero-lateral aspect of the left mid-thigh Oral IPV and OPV 3 Pentavalent 3 PCV 3 14 weeks Intramuscular Intramuscular antero-lateral aspect of the right mid-thigh Intramuscular antero-lateral aspect of the left mid-thigh Measles Rubella 9 months Subcutaneous on left upper arm DPT Booster OPV Booster Measles Rubella 18 months Intramuscular antero-lateral aspect of the right mid-thigh Subcutaneous on left upper arm HPV 9-10 year old girls . Intramuscular
- 58.
- 61. Premature Babies • Babiesshould get their vaccines on time • On their chronological age and not their gestational age • If baby is 30 weeks gestation 2kg and weighs 2.5kg at 6 weeks vaccination should be given • Do not wait for baby to get to 3 kg before vaccines are give
- 62. Other vaccines • Typhoid-3types, schedule • Cholera-outbreak situations
- 63. Take home message •Vaccines prevent infection and childhood diseases • Know your local epidemiology of illness • Try and vaccinate children at every possible encounter • Catchup vaccines • New vaccines – Covid19, Ebola etc
- 64.
Editor's Notes
- #28 Slide 5 Whilst diphtheria typically has a short disease course of a few days, it can last months if complications arise. Diphtheria may also present in a range of clinical manifestations, as described below.1,2 Pharyngeal diphtheria: most common form, abrupt onset with thick membrane covering tonsils, soft palate, oro- and nasopharynx and inflammation of cervical lymph nodes resulting in classical ‘bull-neck’ appearance Laryngeal diphtheria: occurs in 25% cases, particularly in those under 4 years of age and insidious onset with increasing hoarseness Mild fever: diagnosis often missed if not accompanied by pharyngeal diphtheria, which may lead to death Cutaneous diphtheria: indolent skin infection, occurs at wound sites and may act as a source of respiratory infection for others Other: aural, vaginal and conjuctival diphtheria occur in 2% cases and often secondary to pharyngeal infection. References Wharton M, Vitek CR. Diphtheria toxoid. In: Plotkin SA, Orenstein WA, eds. Vaccines. 4th edn. Philadelphia, Saunders: 2004:211–28 2. CDC. Diphtheria. In: Epidemiology and Prevention of Vaccine-Preventable Disease. 8th edn. Atlanta: US Centers for Disease Control and Prevention, 2005:55–64
- #30 The anaerobic bacteria are usually introduced into the umbilical stump of newborn babies when cut with unsterile instruments (rasors), or when the wound is dressed with contaminated materials leading to neonatal tetanus. Affects neural tissue
- #35 Slide 9 The incubation period for pertussis is usually between 7–10 days but can last up to 3 weeks.1,2 During this period, Bordetella pertussis invades the mucosa of the nasopharynx, trachea, bronchi and bronchioles. This invasion increases mucus secretion which is initially thin and later becomes viscid. The disease is divided into three distinct stages: catarrhal, paroxysmal and convalescent stages. During the catarrhal stage, symptoms are often mild and can be indistinguishable from common upper respiratory tract infections such as influenza. Towards the end of this stage, a dry hacking cough develops.2,3 The paroxysmal stage occurs 10–14 days after exposure to B. pertussis and is associated with an increase in the severity and frequency of rapid coughing, which is followed by a hurried, deep inspiration through a partially closed glottis which causes the characteristic ‘whoop’ associated with the disease. Large amounts of viscid mucus are produced, and vomiting, due to the cough or due to gagging on the mucus, is characteristic. During the convalescent stage, which usually occurs within 2–4 weeks, the coughing and vomiting become less frequent. The coughing may recur for months (‘100-day cough’) and may be exacerbated by subsequent respiratory infections.2,3 References Linnemann CC Jr. Bordetella. In: Warrell DA, Weatherall DJ, Cox TM, Firth JD, DA eds. Oxford Textbook of Medicine. 4th edn. Oxford, Oxford University Pres: 2003:525–27 2. CDC. Pertussis. In: Epidemiology and Prevention of Vaccine-Preventable Disease. 8th edn. Atlanta: US Centers for Disease Control and Prevention, 2005:75–88 3. Mortimer EA. Pertussis and pertussis vaccine:1990. Adv Pediatr Infect Dis 1990;5:1–33
- #36 Slide 10 The most common complications of pertussis are secondary respiratory tract infections such as pneumonia. Other complications, including haemorrhages in the eye, nose bleeds, hernias and physical damage to the lungs, may occur as a result of severe coughing. Central nervous system complications, ranging in severity from minor convulsions to coma and permanent brain damage, may be caused by a lack of oxygen reaching the brain or cerebral haemorrhage occurring as a result of coughing. Complications of the disease can be fatal, the most common causes of death being pneumonia and atelectasis (incomplete expansion of the lung).1,2 The risks of complications and mortality are highest in infants (particularly those under 1 year old) and negligible in children of school age;3 87% deaths occur in infants under 1 year of age.3 The highest reported rates of pertussis-associated hospitalisation (82%), pneumonia (25%), seizures (4%), encephelopathy (1%) and death (1%) occur in infants aged under 2 months.4 References 1. Mortimer EA. Pertussis and pertussis vaccine:1990. Adv Pediatr Infect Diseases 1990;5:1–33 2. CDC. Pertussis. In: Epidemiology and Prevention of Vaccine-Preventable Disease. 8th edn. Atlanta: US Centers for Disease Control and Prevention, 2005:75–88 3. Wortis N, Strebel PM, Wharton M, Bardenheier B, Hardy IR. Pertussis deaths: report of 23 cases in the United States, 1992 and 1993. Pediatrics 1996;97:607–12 4. Farizo KM, Cochi Sl, Zell ER, Brink EW, Wassilak SG, Pariarca PA. Epidemiological features of pertussis in the United States, 1980–89. Clin Infect Dis 1992;14:708–19
- #45 NOTE: WHO differs in that only severe immunosuppression is a contra-indication
- #54 Vaccines are usually given by injection. Most live-attenuated viral vaccines or non-adjuvanted vaccines are given by the subcutaneous route. Adjuvanted and sub-unit as well as combined vaccines are generally given intramuscularly. Injections are usually made into the antero-lateral muscle of the thigh in babies and into the deltoid muscle of the upper arm in older subjects. Vaccines should not be injected into the buttocks because then they may be deposited in fat layers which reduces their immunogenicity. The BCG tuberculosis vaccine is injected intradermally. This route shouldn’t be used for any other vaccines as it is unlikely to provoke an adequate immune response or serious local side effects. Other ways of administering vaccines are continually being investigated. People who don’t like injections would find orally administered vaccines much more acceptable than injectable vaccines but, to date, the only oral vaccines are the Sabin polio vaccine and a live-attenuated typhoid fever vaccine. Intranasal vaccination may be feasible for some vaccines to prevent respiratory diseases. Vaccines are never given intravenously. There is a serious risk of a severe reaction if antigens were to be administered directly into the blood stream. Adrenalin or epinephrine solutions should always be readily available in case of rare anaphylactic reactions.