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Newer Vaccines. Presenter: Dr K. Sushma Moderator:Dr Sanam Anwar. Framework :. Introduction Immunization Vaccine Regulation & testing of vaccines Type of vaccines :. HPV Malaria Pandemic -influenza A (H1N1) Rotavirus Cholera vaccine Meningococcal. Japanese encephalitis
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Newer Vaccines Presenter: Dr K. Sushma Moderator:Dr Sanam Anwar
Framework: • Introduction • Immunization • Vaccine • Regulation & testing of vaccines • Type of vaccines: • HPV • Malaria • Pandemic -influenza A (H1N1) • Rotavirus • Cholera vaccine • Meningococcal • Japanese encephalitis • Yellow fever • Hepatitis A&B • Varicella • Haemophilus Influenza B • Pneumococcal
Introduction: • Immunization: • Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine • Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert over 2 million deaths each year • It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations • It has clearly defined target groups, it can be delivered effectively through outreach activities, and vaccination does not require any major lifestyle change
Vaccine • Immunobiological substance • Specific protection • Most powerful & cost effective disease prevention tool • Primarily for Prevention of infectious diseases now for non-infectious diseases(e.g. fertility, autoimmune disease & cancer) Immunizing agents: Vaccines: • Live attenuated vaccines: BCG, typhoid, oral polio plague, yellow fever,measles,mumps,rubella • Inactiavted/Killedvaccines:Typhoid,cholera,pertussis,rabies,polio(salk) • Toxoids:Diptheria &tetanus Immunoglobulins: • Hepatitis A,measles,rabies,diptheria,tetanus
Regulation & testing of vaccines • Phase I: This is a human trial and it focuses on safety involving small groups. • Phase II: Involves moderate-sized "target" populations (persons close to the age and other characteristics for whom the vaccine is intended) to determine both safety and the stimulation of immune response • Phase III: In this phase extensive testing performed on large target populations to establish whether a vaccine actually prevents a disease as intended (efficacy)
Malaria vaccine: Mosquirix (RTS,S): • Recombinant protein-based virus-like particle malaria antigens (circumsporozoite protein )on Hepatitis B particle • 30% efficacy against clinical malaria,57% efficacy against severe malaria • RTS,S induces production of antibodies and T cells that interfere with the ability of the malaria parasite to infect humans • Based on normal timelines that could see Mosquirix reaching the market in 2012. • Mosquirix vaccine is currently in final-stage clinical trials, GlaxoSmithKline reported. • Mosquirix will be tested in some 16,000 children and infants at 11 trial sites in seven countries.
Pandemic influenza A (H1N1) vaccines: • Pandemic influenza A (H1N1) vaccines be available for use as early as September 2009 • Most of these vaccines will be produced using chicken eggs, while a few manufacturers are using cell culture technology for vaccine production • Health care workers worldwide should be immunized as a first priority • A maximum of 4.9 billion doses potentially could be produced in 12 months.
Meningococcal vaccine: Indications: • Travellers to industrialized countries are exposed to the possibility of sporadic cases. • Outbreaks of meningococcal C disease occur in schools, colleges, military barracks and other places where large numbers of adolescents and young adults congregate. • Travellers to the sub-Saharan meningitis belt may be exposed to outbreaks of serogroup A disease & high incidence rates are seen during the dry season (December–June). • Long-term travellers living in close contact withthe indigenous population may be at greater risk of infection. • Pilgrims to Mecca are at risk.
Continuation…………… • Polysaccharide vaccines: • meningococcal polysaccharide vaccines are either bivalent(A and C) or tetravalent (A, C, Y and W-135) • Only one dose which provides protection for3–5 years • Vaccine should not given when there is serious adverse reaction to previous dose • Occasional mild local reactions; rarely, fever • Vaccine should be given 2 weeks before departure • Children under 2 years of age are not protected by thevaccine • Travellers should opt (A, C, Y,W-135) than the bivalent vaccine because of the additional protection against groups Y and W-135 • No protection against group B meningococci, whichare the leading cause of endemic meningococcal disease in some countries
Conjugate vaccine: • Monovalentserogroup C conjugate vaccines were first licensed for use in 1999 are now incorporated in national vaccination programmes in an increasing number of countries. • Increased immunogenicity among infants and prolonged duration of protection in infants who are vaccinated at 2, 3 and 4 months of age. • Tetravalent conjugate vaccine (A, C, Y, W-135) has been licensed in a limited number of countries.
Japanese Encephalitis: • Indications: • Vaccination is recommended for travellers with extensive outdoor exposure (camping, hiking, bicycle tours, outdoor occupational activities, in particular in areas where flooding irrigation is practised) • In rural areas of an endemic region during the transmission season. • It is also recommended for expatriates living in endemic areas through a transmission season or longer. • Two types of JE vaccine are widely available • inactivated mouse-brain-derived vaccine (IMB) • cell-culture-derived live attenuated SA 14-14-2 vaccine.
Inactivated mouse-brain-derived Dose:0.5 or 1.0 ml for adults, 0.25 or 0.5 ml for children depending on the vaccines Schedule:3 doses given 0, 7 and 28days.If 2doses given preferably 4 weeks apart.Booster after 1 year and then 3-yearly Contraindications: • Hypersensitivity to a previous dose of vaccine, pregnancy • and immunosuppression Adverse reactions: • Occasional mild local or systemic reaction; occasional • severe reaction with generalized urticaria, hypotension • and collapse Before departure:At least two doses
Cell-culture-derived live attenuated SA 14-14-2 vaccine Dose:0.5 or 1.0 mlfor adults, 0.25 or 0.5 ml for children depending on thevaccines.Single dose given Booster: • single booster dose given at an interval of about 1 year Contraindictaions: • Hypersensitivity to a previous dose of vaccine, pregnancy • and immuno suppression Adverse effects: • Occasional mild local or systemic reaction; occasional • severe reaction with generalized urticaria, hypotension • and collapse Before departure: • one dose
Hepatitis B • Three doses given the first two doses are usually given 1 month apart, with the third dose 1–12 months later • Protection for at least 15 years and probably for life. Boosters are not recommended. • Because of the prolonged incubation period of hepatitis B, some protection will be afforded to most travellers following the second dose given before travel. The final dose should always be given upon return. • A rapid schedule of administration of monovalent hepatitis B vaccine has been given day 0, 1 month 2 months. An additional dose is given 6-12 months after the first dose. • A very rapid schedule of administrationof hepatitis B vaccine has been proposed day 0, 7 , 21 days. An additional dose is given at 12 months.
Hepatitis B • A combination vaccine that provides protection against both hepatitis A and hepatitis B should be considered for travellers potentially exposed to both organisms • This inactivated vaccine is administered as follows day 0,1 month, 6 months. • A rapid schedule at day 0, 1 month and 2 months, with an additional dose at 12 months • Very rapid schedule with administration at day 0, day 7 and day 21 with a booster dose at 12 months
Varicella: • In several industrialized countries, varicella vaccines have been introduced into the childhood immunization programmes. • Most adult travellers from temperate climates are immune (as a result of either natural disease or immunization). • Adult travellers without a history of varicella who travel from tropical countries to temperate climates may be at increased risk and should consider vaccination. • Use at 9 months of age and older. optimal age for varicella vaccination is 12–24 months. • In Japan and several other countries 1 dose of the vaccine is considered sufficient regardless of age. • In the United States2 doses4–8 weeks apart, are recommended for adolescents and adults.
Varicella vaccine: Side effects: • Mild varicella-like disease with rash within 4 weeks. Contraindications • Pregnancy (pregnancy should be avoided for 4 weeks following vaccination), • Ongoing severe illness • Anaphylactic reactions • Immuno suppression.
Haemophilusinfluenzae type b (Hib): Indications: • Pneumonia,respiratory infection common in children < 2 years Vaccine • Conjugate polysaccharide b vaccine Schedule: • 6,10,14 weeks booster at 12-15 months Dose: • 0.5 ml imant.lat.aspectof thigh Contrindictaions: • Local pain,erythema,fever
Influenza vaccine: • There are 2 influenza viruses, types A and B. • Type A :subtypes based on two surface antigens Hemagglutinin (H) and Neuraminidase (N). egH1N1 • Influenza type B is not categorized into subtypes. • There are two vaccines available: • The inactivated killed Vaccine • Live attenuated influenza vaccine • Both vaccines includes Two type A strains (eg H3N2 and H1N1) & One type B strain • The inactivated killed Vaccine • 2 doses 4 weeks apart recommended. Immunity lasts for 3-6 months so annual revaccination recommended. • Live attenuated influenza vaccine • Given only to healthy persons 5 to 49 yrs of age who are not in contact with severely immuno-suppressed persons • Intra nasally annually to optimize protection
Pneumococcal vaccine: • Pneumococcal conjugated vaccine(PCV7): -infants and toddlers(6 weeks to 9 years) • Pneumococcal polysaccharide vaccine(PV23): • This vaccine is widely licensed for use in adults and children aged >2 years who have certain underlying medical conditions.( Sickle cell disease, damaged spleen/spleenectomised, AIDS, disease affecting immune system ,diabetes, liver ds. chronic lung ds, chronic heart disease, who is on immunosuppresive therapy). • Dose: 0.5 ml • Schedule s/c or i.m • <6 months 3 doses (6, 10, 14wks) • 7-11 months- 2 doses & booster after 1yr • 12-23 months-2 doses • >24mnths single dose
Pneumococcal vaccine: • Side-effects: Redness, tenderness, swelling ,fever, loss of appetite, irritability, drowsiness • Contraindications: Allergic reaction to 1st dose, Severely ill
References: • WHO textbook International travel and health January 2009 • www.who.int • Weekly Epidemiological Records