Selected Vaccine-preventable Diseases and Vaccines| Category | Tuberculosis | Diphtheria | Tetanus | Pertussis | Poliomyelitis | Measlesa | Rubella | Hib | Hepatitis B | Yellow fever | Meningococcal disease | Japanese encephalitis |
| Causative agent | Mycobacterium tuberculosis | Toxin-producing bacterium (Corynebacterium diphtheriae) | Toxin-producing bacterium (Clostridium tetani) | Bacterium (Bordetella pertussis) | Virus (serotypes 1, 2, and 3) | Virus | Virus | Bacterium (Haemophilus influenzae type B) | Virus | Virus | Neisseria meningitis groups A, B, C, Y, W135 | Virus |
| Reservoir | Humans (some bovine) | Humans | Animal intestines; soil | Humans | Humans | Humans | Humans | Humans | Humans | Monkeys and humans | Humans | Birds and mammals |
| Spread | Airborne droplet nuclei from sputum-positive persons | Close respiratory or cutaneous contact | Spores enter the body through wounds or the umbilical cord stump | Close respiratory contact | Fecal-oral; close respiratory contact | Close respiratory contact and aerosolized droplets | Close respiratory contact and aerosolized droplets | Close respiratory contact | Blood, perinatal, household, occupational, or sexual transmission | Bites by infected mosquitoes | Close respiratory contact | Bites by infected mosquitoes |
| Transmission period | As long as sputum acid-fast bacilli are positive | Usually under two weeks; some chronic carriers | No person-to-person transmission | Usually under three weeks (starts before cough is apparent) | A few days before and after acute symptoms | Four days before rash until two days afterward | A few days before to seven days after rash; up to one year of age in congenitally infected | Chronic carriage for months | Up to lifelong chronic carriage and transmission | Infected individuals can transmit the disease when bitten by a mosquito vector during the viremic phase (the first three or four days of illness) | Chronic carriage for months | Unknown, rare cases for several months |
| Subclinical infection | Common but not important in transmission | Common | No | Mild illness common: may not be diagnosed | More than 100 subclinical infections for each paralytic case | May occur in children under one, but relative minimal | Common | Common | Common, especially in infants | Common | Common | Common |
| Duration of natural immunity | Not known; reactivation of old infection commonly causes disease | Lasting protective immunity not produced by infection; second attack possible | Lasting protective immunity not produced by infection; second attack possible | Incomplete and waning protection | Lifelong type- specific immunity | Lifelong | Lifelong | Uncertain; no protection against carriage and those previously infected may develop some disease (epiglottitis) | If develops, lifelong | Lifelong | Uncertain; no protection against carriage | Lifelong |
| Risk factors for infection (for unvaccinated individuals) | High population densities in regions with historically poor control; low socioeconomic status; poor access to care; immunodeficiency; malnutrition; alcoholism; diabetes | Crowding; low socioeconomic status | Wound contaminated by soil; umbilical cord; agricultural work | Young age; crowding | Poor environmental hygiene and sanitation | Highly transmissible agent with nearly 100 percent infectivity except for isolated populations; crowding, low socioeconomic status | Highly transmissible; crowding; low socioeconomic status | Failure to breastfeed; crowding; low socioeconomic status; immune deficiency, including HIV | Carrier mother, sibling, or sex partner; multiple sex partners; intravenous drug use; unsafe injection practices | Young age; forest workers; season (late rainy season, early dry season) | Crowding; respiratory viral infections, especially influenza | Young age; forest workers; season |
| Case-fatality rateb | See chapter 16 | 2 to 20 percent | 25 to 90 percent | Up to 10 percent in infants and children | 2 to 10 percent | 0.05 to 10.0 percent | Less than 0.1 percent | Meningitis, 5 to 90 percent; pneumonia 5 to 25 percent | Acute, more than 1 percent; chronic; 25 percent (delayed) | 10 to 40 percent | Untreated 90 to 100 percent; treated 5 to 20 percent | 5 to 30 percent |
| Vaccine (number of doses); route | BCG attenuated Mycobacterium bovis (1); intradermal | Diphtheria toxoid (three to five primary including booster doses in most countries); intramuscular | Tetanus toxoid (three to five in children, including booster doses in many countries; five for women of childbearing age; adult boosters for injury prevention); intramuscular | Killed whole-cell or acellular pertussis (three to five, including booster doses in most countries); intramuscular | Live (OPV) (three to four primary plus campaigns);c killed (IPV) (three to four) | Measles (two); subcutaneous | Rubella (one or two); subcutaneous | Capsular polysaccharide linked to protein Hib (three to five); intramuscular | Hepatitis B surface antigen (three to four); intramuscular | Yellow fever attenuated live virus (1 plus boosters); subcutaneous | Vaccines for A, C, Y, Wi35 only; unconjugated polysaccharides given subcutaneously or intramuscularly: one dose with repeat three to five years later for high-risk persons; conjugated: for C only or A, C, Y, + Wi35, one dose given intramuscularly | Live attenuated (two, China only); killed (two); booster commonly used but of uncertain value |
| Vaccine efficacy | 0 to 80 percent for pulmonary tuberculosis; 75 to 86 percent for meningitis and miliary tuberculosis | More than 87 percent | More than 95 percent (more than 80 percent after two doses) in infants | 70 to 90 percent | OPV: more than 95 percent in industrial countries; 72 to 98 percent in developing countries; lower protection against type 3 than 1 and 2; IPV: more than 95 percent | 95 percent at 12 months of age; 85 percent at 9 months of age from one dose, more than 98 percent from two doses | 95 percent (at 12 months and up) | More than 95 percent for invasive disease | 75 to 95 percent; efficacy against chronic infection in infants born to carrier mothers; more than 95 percent for exposure at older ages | 90 to 98 percent | Unconjugated polysaccharides: poor efficacy under two years of age; conjugated polysaccharides: approximately 95 percent and up serogroup specific | Live attenuated: 90 percent (after one dose at one year); 94 to 100 percent (after two doses one to two months apart); inactivated: 80 percent (declining to 55 percent after one year; no decrease in another study) |
| Duration of immunity after primary series | Unknown; some evidence that immunity wanes with time | Variable: probably around five years; longer in presence of natural boosting or booster doses | 10 years or more | Unknown; wanes with time | Presumed lifelong for both OPV and IPV, but unknown | Lifelong in most; rare cases of waning immunity after one dose, not two | Lifelong in most; presumed rare cases of waning immunity after one dose, not two | Unknown, but lasts for at least three years beyond period of greatest exposure | More than 15 years; further follow-up is continuing | For at least 10 years and possibly for life | Unconjugated wanes rapidly for children under five, more than three to five years for older children; conjugated uncertain | Unknown, may be lifelong |
| Schedule | Given at or near birth in populations at high risk | Three-dose schedule recommended at 6, 10, and 14 weeks in developing countries for DTP vaccine; other schedules in common use; booster doses at 18 months and four to six years also suggested | Normally given as DTP vaccine to children; unimmunized pregnant women should be given two doses of tetanus toxoid or tetanus reduced diphtheria toxoid, and a total of five doses is required to provide protection through all childbearing years | Usually given in childhood as combination vaccine (DTP) | OPV: four doses (birth, 6, 10, and 14 weeks) in polioendemic countries; birth dose may be omitted elsewhere with fourth dose given later; supplemental doses (up to 10) given in national campaigns for eradication; IPV: three to four doses: 2, 4, 6 to 18 months, and four to six years | First dose at 9 or 12 to 15 months); a second opportunity to receive a dose of measles vaccine (either through routine [18 months or four to six years] or supplemental immunization activities) should be provided for all children | First dose at 12 to 15 months; when given, a second dose with measles vaccine | Three or four doses; usually given during the same visit as for DTP | Several schedules: at birth, 6, and 14 weeks; with first three doses of DTP; birth dose needed if mother is a carrier and recommended if perinatal transmission of hepatitis B is frequent; four doses total can be given although only three are required | One dose at 9 to 12 months with measles in countries where yellow fever poses a risk | Unconjugated: one dose at two years or older and second dose three to five years later for high risk; conjugate C: three doses at two, three, and four or two, four, and six months for infants; one dose for older children and adults; conjugate A, C, Y, Wi35 currently only approved for one dose at 11 years or older | Live: one year and two years; killed: days 0, 7, and 30 followed by booster two years later and then every three years |
| Status as of the end of 2001 | 158 countries using BCG; 85 percent coverage | All countries; 78 percent coverage | Childhood: all countries; 78 percent coverage | All countries; 78 percent coverage | All countries; 79 percent routine, plus supplemental coverage | Routine first dose all countries, 77 percent coverage; second opportunity, 164 out of 192 countries | 110 countries in 2003 | 89 countries; global coverage less than 18 percent | 147 countries; global coverage 42 percent | 29 of 43 countries at risk using vaccine; 30 percent coverage in target population | European countries, Canada (and United States in 2005) | Southeast Asia |
| Comments | Reasons for varying efficacy are multifactorial, including differences in vaccines | Recent trends to lower antibody levels in adults without booster doses because of waning immunity and less natural boosting | Five doses in adults provide protection for more than 20 years | Variability in whole cell vaccines; acellular vaccines used in some developed countries | Primary series gives incomplete protection in developing countries | Lower efficacy when maternal antibody present | Lower efficacy when maternal antibody present | None | Efficacy lower if injected into fat | None | None | None |
