Immunizations

Immunizations

Vaccine A suspension of attenuated live or killed microorganisms administered to induce immunity Toxoid A modified bacterial toxin, now nontoxic, which stimulates formation of antitoxins Active immunity Results when an antibody is produced in response to a vaccine or toxoid

Passive immunity Occurs when performed antibodies are given, resulting in temporary immunity Herd immunity Results when enough persons are immunized to prevent transmission of disease to unimmunized persons

Whole

Live attenuated Viral

MMR, varicella, yellow fever, polio Bacteria (OPV) BCG, oral typhoid

Inactivated Virus

Fractional Protein based

Polio, rabies, hepatitis A Subunit: hepatitis B, influenza, acellular pertussis Toxoid: diphtheria, tetanus Pure: pneumococcal, Hib,

Composition of vaccines

•All vaccines containing an adjuvant must be administered intramuscularly. Such injections given at a 90ο angle into the anterolateral thigh (not intragluteally) in infants (< age 18 months) and may be given in the deltoid or triceps in older children •Subcutaneous injections given at a 45ο angle into the anterolateral aspect of the thigh or the upper outer triceps area •Intradermal injections given on the volar surface of the forearm with the bevel facing upward using a ⅜–¾ inch 25- to 27-gauge needle

Simultaneous administration of vaccines •Inactivated vaccines may be given simultaneously at separate sites, except cholera, typhoid, and plague •Live virus vaccines given on different days should be administered 1 month apart •Pneumococcal polysaccharide and whole virus influenza can be given simultaneously, at different sites

If an immunoglobulin (Ig) or blood product has been administered, live-virus vaccination should be delayed 3–11 months to avoid interference with the immune response: •3 months for tetanus Ig, hepatitis A Ig, and hepatitis B Ig, •5–6 months for measles Ig or cytomegalovirus Ig (CMVIg), and •11 months for intravenous Ig for Kawasaki disease

Hypersensitivity •Avoid it •Egg hypersensitivity can occur with influenza and yellow fever vaccines •Neomycin is contained in IPV , measles, mumps, rubella, and MMR •Streptomycin is contained in IPV and MMR

Contraindications and Precautions Contraindications to vaccines •Permanent Severe allergy to a prior dose of vaccine or to a component •Temporary Pregnancy and immunosuppression – vaccine deferral as indicated

Misconceptions The following are not contraindications to immunizations •A reaction to a previous DPT of temperature < 105ο F, redness, soreness and swelling •A mild, acute illness in an otherwise well child •Concurrent antimicrobial therapy •Prematurity – immunize at the chronological age •A family history of seizures • A family history of sudden infant death syndrome

Immunizations in special circumstances •Immunocompromised No live virus vaccine But poor response to inactivated •Preterm infants Immunize at chronologic age Do not reduce dosage

•Vaccines against seven diseases are currently recommended by the EPI for routine use in the developing world •BCG, DTP, OPV, measles, and hepatitis B vaccines for children and tetanus toxoid for pregnant women •Hib, Yellow fever, Japanese encephalitis, group A meningococcus, mumps, and rubella vaccines are used regionally, depending on the disease epidemiology and resources

Expanded program on immunization (EPI) •Routine immunization schedule comprises 7 vaccine preventable diseases, namely tuberculosis, polio, diphtheria, pertussis, tetanus, measles, and hepatitis B •Before the age of one year, the routine immunization schedule should be completed by all children •Women of childbearing age are given tetanus toxoid vaccine to protect their unborn babies from tetanus •The mothers and their future babies obtain full protection after completing the TT schedule

Routine immunization schedule (developing countries) Vaccine Diseases BCG Tuberculosis DPT Diphteria, Pertussis, Tetanus OPV Polio Measles Measles HepB Hepatitis B

Age At birth 6, 10, 14 weeks

(At birth), 6, 10, 14 weeks 9 months 0, 1, 6 months (6, 10, 14 weeks)

Schedule for Tetanus Toxoid administration Dose Time for administration Duration of protection TT1 TT2 TT3 TT4 TT5

At first contact No protection 4 weeks after TT1 Three years At least 6 months after TT2 Five years At least one year after TT3 Ten years At least one year after TT4 For thirty years (throughout a woman’s reproductive life)

Childhood Immunization Schedule (US) Age Birth 2mo 4mo 6mo. 6-18 mo 12-15mo > 12 mo 15-18mo 4-6 yr

Immunizations HBV (1) HBV(2)

DTaP (1) DTaP (2) DTaP (3)

Hib (1) Hib (2) Hib (3)

HBV(3)

IPV(1) IPV(2)

PCV(1) PCV(2) PCV(3)

IPV(3) Hib(4)

PCV(4)

MMR(1) Varicella

DTaP (4) DTaP (S)

IPV(4)

MMR(2)

•Influenza vaccine recommended annually for children aged 6 months to 24 months and for all children >6 months with chronic pulmonary, cardiovascular, metabolic, or sickle cell disease •Tetanus-diphtheria vaccine is given at age 11 years and then every 10 years thereafter

General rules for catch-up vaccines For lapsed vaccines, •resume schedule as if usual interval has elapsed •do not repeat doses of HiB •PCV 7 not needed again if immunocompetent child is >= 5 years old •Second-dose HiB indicated only if first dose is given >15 months of age •Second-dose PCV 7 only if child >2 years •If unsure and no proof of immunizations, assume none and vaccine from beginning

Lapses in the immunization schedule do not call for reinstitution of the series •Extra doses of hepatitis B (HepB), Haemophilus influenzae type B (Hib), MMR, or VAR are not harmful •Repetitive exposure to tetanus vaccine beyond the recommended intervals can result in hypersensitivity reactions and should be avoided

Immunization recommendations for HIV infection

Bacille Calmette-Guérin vaccine (BCG) •consists of live attenuated Mycobacterium bovis •inexpensive, can be given any time after birth •sensitizes the vaccinated individual for 5–50 yrs •stimulates both B-cell and T-cell immune responses •BCG reduces the risk of tuberculous meningitis and disseminated TB in pediatric populations by 50–100% when administered in the first month of life.

Adverse effects •occur in 1–10% of healthy individuals, •local ulceration, regional lymph node enlargement, and lupus vulgaris. Contraindication •pregnant women •immunocompromised individuals, including those with HIV infection

Interpretation of Tuberculin Skin Test (Mantoux test) Reactions

Risk Factors

Recent close contact with a case of active tuberculosis; chest x-ray compatible with tuberculosis; immunocompromise; HIV infection

Positive Reaction 5 mm induration

•Current or previous residence in high10 mm prevalence area (Asia, Africa, Latin America); induration •skin test converters within past 2 years; •intravenous drug use; •homelessness or residence in a correctional institution; •recent weight loss or malnutrition; •leukemia, Hodgkin disease, diabetes mellitus; •age < 4 years

Positive induration reaction in Mantoux test •5-mm or greater cutoff for a positive Mantoux test is used in immunocompromised children. •Cutoff is 10 mm or above in immunocompetent persons •Cutoff is 15 mm or above when no risk factors are present in the absence of clinical disease (eg, screening).

Strongly positive Mantoux test in a patient with active tuberculosis. Intradermal injection of M. tuberculosis antigen has induced a florid type IV hypersensitivity reaction with some blistering.

Factors associated with increased probability that a positive TB skin test is due to M tuberculosis infection include (1) larger reactions, (2) contact with an individual known to be infected, (3) family history of TB, (4) longer interval between BCG administration and skin testing, and (5) country of origin with increased incidence of endemic TB.

•BCG almost invariably causes its recipients to be tuberculin-positive (5–7 mm) •Reaction often becomes negative after 3–5 years •A positive Mantoux test in a child with a history of BCG vaccination who is being investigated for TB as a case contact should be interpreted as indicating infection with M tuberculosis.

Polio Eradication Initiative One of a small limited number of diseases that can be eradicated Reasons why polio can be eradicated are: - polio only affects humans, and there is no animal reservoir - an effective and inexpensive vaccine exists, called Oral PolioVirus (OPV) - immunity against polio is life-long - the virus can only survive for a very short time in the environment

•Injectable •Killed polio vaccine (Inactivated) •Incapable of causing poliomyelitis (whereas OPV can do so rarely) •Contraindication •Anaphylaxis to neomycin or streptomycin

DTaP Common side effects •fever up to 105o F in the first 24 h, redness, or swelling and soreness at the injection site Less common side effects •Inconsolable crying for > 3 h, temperature >105o F, and a high- pitched cry •Rarely, seizures occur, probably from the fever •No evidence to date that the pertussis vaccine causes brain damage

DTaP Contraindication •serious CNS problem within 7 days of receiving the vaccine, •anaphylactic reaction, •unstable encephalopathy In those cases, DT should be substituted Acetaminophen reduce the discomfort of the side effects In patients with prior history of pertussis, the pertussis component may be left out of subsequent vaccines

Common sided effects of the MMR include sore arm for 1-2 days Most effects occur 1-2 weeks after immunization Measles Rash, fever, upper respiratory infection symptoms Mumps Slight salivary gland swelling

Rubella Cervical lymph adenopathies Arthralgia All the vaccines can cause febrile seizures and reversible encephalopathy MMR should be delayed for •Pregnancy or possibility of pregnancy •Anything more than a minor illness, and •Patient receiving gammglobulin in the past 3 months

Contraindications •Anaphylaxis to any of its components •Immunodeficiency (such as cancer, leukemia, severe HIV immunosuppression, radiation therapy, chemotherapy, and steroids)

HiB Side effects •Local swelling and low-grade fever •Invasive HiB disease under 2 years of age does not confer immunity, and the patient still requires immunization •One dose of HiB given after 15 months of age confers immunity, and there is no need to give the entire series

•Pneumococcal vaccine recommended for all children beginning at 2 months of age •A heptavalent conjugated vaccine used •All children >2 years of age with sickle cell anemia, functional or anatomic asplenia, and immunosuppression should receive pneumococcal vaccine (23 valent)

•Now universally recommended •Patients born to hepatitis B surface antigennegative mothers receive vaccine in the usual time schedule •Patients born to hepatitis B surface antigenpositive mothers also require hepatitis B immune globulin along with the first dose of vaccine

Perinatal transmission If mother is HBsAg+ and HbeAg: •70 – 90% infants infected •90% infected become carriers If mother only HBsAg+: •20% infants infected •90% infants become carriers

Prevention of Perinatal HBV infection •Begin prevention within 12 h of birth •HBV and HBIG at different sites •85 – 95% successful Adolescent HBV alternative •Two-dose adolescent schedule (11 – 15 years) separated by 4 – 6 months

•Does not cover all serogroups •Active immunization against serotypes A, C, Y, and W-125 •Not protective for those <2 years of age

MCV4 is the preferred vaccine for people 11-55 years and should be given to: •All adolescents at their11-12 yr health maintenance visit •All adolescents as they enter high school if not previously immunized •Other adolescents who want to decrease their risk of meningococcal disease •Microbiologists •Military recruits •People living in or traveling to areas where meningococcus is endemic •People with a damaged spleen or asplenia •People with terminal complement deficiency •People exposed during a meningococcal outbreak

•Live attenuated vaccine scheduled for all children 12 – 18 months of age and all children without a history of varicella •Patients aged 12 months to 12 years have a 95% seroconversion rate •Children younger than 12 years of age receiving the vaccine require two doses at least 4 to 8 weeks apart for effective seroconversion

•The vaccine is 100% protective against severe disease •Breakthrough infections can occur that may result in mild disease •Mild varicella with <50 lesions may still be contagious

Postexposure prophylaxis with VZIG: •Newborn and mother – 5 days prior to delivery to 2 days after •Susceptible pregnant women •Immune deficiency •Hospitalized preterm infant born at < 28 weeks or weighs < 1000 grams

Contraindications •Moderate to severe acute illness •Malignancy or T-cell defect, including HIV infected with CD4 counts <25% •High – dose steroid treatment •Pregnancy •Component allergy

•Inactivated vaccine produced in embryonated eggs •Duration of immunity is <1 year •Schedule 1 dose annually •Avoid the flu shot in patients with egg anaphylaxis •Consider live attenuated intranasal influenza vaccine

Recommendations •All persons >50 years •Infants 6 – 23 months •Persons > 6 months with chronic illness •Pregnant women – at least 14 weeks •Those 6 months to 18 years receiving salicylates •Split dose <9 years old

Guide to Contraindications and Precautions to Commonly Used Vaccines. Vaccine General for all vaccines, including diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP); pediatric diphtheria-tetanus toxoid (DT); adult tetanus-diphtheria toxoid (Td); inactivated poliovirus vaccine (IPV); measles-mumpsrubella vaccine (MMR); Haemophilus influenzae type b vaccine (Hib); hepatitis A vaccine; hepatitis B vaccine; varicella vaccine; pneumococcal conjugate vaccine (PCV); influenza vaccine; and pneumococcal polysaccharide

True Contraindications and Precautions Contraindications  Serious allergic reaction (eg, anaphylaxis) after a previous vaccine dose Serious allergic reaction (eg, anaphylaxis) to a vaccine component Precautions  Moderate or severe acute illness with or without fever

DTaP Contraindications  Severe allergic reaction after a previous dose or to a vaccine component Encephalopathy (eg, coma, decreased level of consciousness; prolonged seizures) within 7 days of administration of previous dose of DTP or DTaP Progressive neurologic disorder, including infantile spasms, uncontrolled epilepsy, progressive encephalopathy: defer DTaP until neurologic status clarified and stabilized. Precautions  Fever of > 40.5 °C 48 h after vaccination with a previous dose of DTP or DTaP Collapse or shock-like state (ie, hypotonic hyporesponsive episode) 48 h after receiving a previous dose of DTP/DTaP Seizure 3 d of receiving a previous dose of DTP/DTaP   Persistent, inconsolable crying lasting 3 h 48 hours after receiving a previous dose of DTP/DTaP Moderate or severe acute illness with or without fever

— DT, Td Contraindications  Severe allergic reaction after a previous dose or to   a vaccine component Precautions  Guillain-Barré syndrome 6 wk after previous dose of tetanus toxoid-containing vaccine Moderate or severe acute illness with or without fever

IPV

Contraindications  Severe allergic reaction to previous dose or vaccine component Precautions  Pregnancy Moderate or severe acute illness with or without fever

MMR Contraindications    Severe allergic reaction after a previous dose or to a vaccine component Pregnancy Known severe immunodeficiency (eg, hematologic and solid tumors; congenital immunodeficiency; longterm immunosuppressive therapy,or severely symptomatic human immunodeficiency virus [HIV] infection)   Precautions  Recent ( 11 mo) receipt of antibody-containing blood product (specific interval depends on product)   History of thrombocytopenia or thrombocytopenic purpura Moderate or severe acute illness with or without

Hib Contraindications  Severe allergic reaction after a previous dose or to a vaccine component Age < 6 wk Precaution  Moderate or severe acute illness with or without fever

Hepatitis Contraindication  B Severe allergic reaction to yeast, to any vaccine component, or after a previous dose Precautions  Infant weighing < 2000 g  Moderate or severe acute illness with or without fever

Hepatitis Contraindications  A Severe allergic reaction after a previous dose or to a vaccine component Precautions  Pregnancy Moderate or severe acute illness with or without fever

Varicell Contraindications  a Severe allergic reaction after a previous dose or to   a vaccine component Substantial suppression of cellular immunity Pregnancy Precautions  Recent ( 11 mo) receipt of antibody-containing blood product (specific interval depends on product)  Moderate or severe acute illness with or without fever

PCV

Contraindication  Severe allergic reaction after a previous dose or to a vaccine component Precautions  Moderate or severe acute illness with or without fever Meningococ Contraindications  cal (MCV4) Severe allergic reaction to any vaccine component, including diphtheria toxoid, or to dry natural rubber latex Pregnancy Precautions  Prior history of Guillain-Barré syndrome Moderate or severe acute illness with or without fever Influenza Contraindication  Severe allergic reaction to previous dose or vaccine component, including egg protein