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Transcript of N EWER V ACCINES Presenter – Pramod Kumar Sah Moderator – Dr. Subodh S. Gupta "With the...
NEWER VACCINES
Presenter – Pramod Kumar Sah
Moderator – Dr. Subodh S. Gupta
"With the exception of safe water, no other modality, not even antibiotics, has had such a major effect on mortality reduction…"
FRAMEWORK
Introduction Vaccine Development of vaccines Need for new vaccines Regulation & testing of vaccines Newer / Improved vaccines Vaccine on clinical trial
VACCINE
It is a suspension of attenuated or killed microorganisms, or of antigenic proteins derived from them, administered for prevention or amelioration of infectious diseases.
Helps stimulate the body's own immune system to produce antibodies to fight particular disease.
Vaccine may contain live but avirulent organism, or killed microorganism , or purified macromolecular component of a microorganism or a plasmid that contains a complementary DNA encoding a microbial antigens. Antibodies that are produced to protect against future infection.
Type of Vaccine Disease
Live, attenuated vaccine Measles, mumps, rubella, polio (Sabin vaccine), yellow fever
Inactivated or “killed” vaccine
Cholera, flu, hepatitis A, Japanese encephalitis, plague, polio (Salk vaccine), rabies
Toxoid vaccine Diphtheria, tetanus
Subunit vaccines Hepatitis B, pertussis, pneumonia caused by Streptococcus pneumoniae
Conjugate vaccines Haemophilus Influenza type B, pneumonia caused by Streptococcus pneumoniae
DNA vaccines In clinical testing
Recombinant vector vaccines In clinical testing
THE DEVELOPMENT OF VACCINES
First generation—whole - organism vaccines - Inactivated/Killed,
-live attenuated Second generation
subunit vaccine, recombinant antigen Vaccine,, synthetic peptide vaccines
Third generation----DNA vaccine
YEAR MILESTONES
1796, Inoculation of pus from the hand of a milkmaid with cowpox
1881 First vaccine against rabies,
1896 Vaccine for cholera and typhoid
1897 Plague vaccine
1923 Use of diphtheria "toxoid" to kill bacteria.
1926 A killed vaccine for pertussis ("whooping cough")
1927 A tetanus "toxoid" is developed.
1954 Jonas Salk develops a killed polio virus vaccine
1961 Alfred Sabin develops an oral polio vaccine using a live virus
1963 Measles vaccine
1964 A killed rabies vaccine
1967 Mumps
1970s Meningoccocal, pneumococcal and haemophilus influenza type b (Hib) vaccines are developed,
1986 A vaccine for Hepatitis B is licensed with an antigen that is cloned rather than grown.
1990 A killed vaccine for hepatitis A is developed
1995 A varicella (chicken pox) vaccine is licensed for use in children
2005-6 RotaTeq vaccine
2003 1st Vaccine for Influenza
2006 1st vaccine for HPV
2009 Swine flu vaccine
2011 Pentavac vaccines
NEED FOR NEW VACCINES
Pathogens that have circulated for long but existence ignored : HepB, Pneumococcal diseases, Rota - virus
Old pathogens change geographical habitat and are introduced into newer areas : Chikungunya, West Nile
New pathogens have emerged : SARS, Avian Flu
Pathogens thought to be controlled have re-emerged : M tuberculosis
FRAMEWORK FOR DECISION MAKING ON INTRODUCING NEW VACCINES
Is the disease a public health problem? Is immunization the best control strategy for this disease? Is the immunization programme working well enough to add a vaccine? What would be the net impact of the vaccine? Is the vaccine a good investment? How will be the vaccine funded? How will the addition of the new vaccine be implemented?
REGULATION & TESTING OF VACCINES
Phase I: is a human trial & focuses on safety involving small groups.
Phase II: Involves moderate-sized "target" populations to determine both safety and the stimulation of immune response
Phase III: extensive testing performed on large target populations to establish whether a vaccine actually prevents a disease as intended (efficacy)
GENERAL WHO POSITION ON NEW VACCINES
Vaccines for large-scale public health use should: meet the quality requirements as defined in the Global Programme on
Vaccines policy statement on vaccine quality be safe and have a significant impact against the actual disease in all
target populations if intended for infants or young children, be easily adapted to schedules
and timing of the national childhood immunization programmes not interfere significantly with the immune response to other vaccines
given simultaneously be formulated to meet common technical limitations, e.g. in terms of
refrigeration and storage capacity be appropriately priced for different markets.
NEWER VACCINES
LICENSED VACCINES THAT ARE NOT BEING USED WIDELY
New/Improved: Hib: PRP-conjugates Pneumococcus: PS-conjugates Cholera: inactivated Rotavirus: live, attenuated Typhoid: Vi, Ty2la HAV: Inactivated Group A Meningococcus: PS-conjugates Varicella: Live-attenuated Human papilioma virus Japanese Encephalitis
VACCINES ON CLINICAL TRIALS
1. Malaria2.Dengue4. HIV
HAEMOPHILLUS INFLUENZAE 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
Unvaccinated children ≥ 7 months of age- 2 doses Unvaccinated children ≥ 15 months of age- 1 dose Unvaccinated children ≥ 5 yrs- only if underlying immune disorder or
asplenia
HIB VACCINES CONT…
Dose: 0.5 ml IM ant.lat.aspect of thigh
Contra-indictaions: Local pain, erythema, fever
Immunogenicity- More than 95% of infants- protective antibody levels after a primary series of two or three doses. Immunogenic in patients with increased risk for invasive disease, such as sickle-cell disease, leukemia, (HIV) infection, splenectomy.
Recently, quadruple vaccine (DPT+Hib) and pentavalent (DPT+Hib+HepB) available.
WHO POSITION
Calls for the use of Hib vaccines in all infant immunization programs and
states that the vaccine is the only public health tool capable of preventing the majority of cases of serious Hib disease.
PNEUMOCOCCAL VACCINE
A. Pneumococcal polysaccharide vaccine (PV23): 1977
- purified cap.polysaccharide Ag from 14 strains(14-valent)
Indication: 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 & heart disease, who is on immunosuppresive therapy).
B .Pneumococcal conjugated vaccine (PCV7): 2000
Composition: Purified cap. Polysaccharide of 7 serotypes(PCV7) of pneumococci (4, 9V, 14, 19F, 23F, 18C, 6B) conjugated to a non toxic variant of diptheria toxin (CRM197)
Indication : infants and toddlers (6 weeks to 9 years)
PNEUMOCOCCAL VACCINE CONT…. Dose: 0.5 ml Schedule – S/C or IM
<6 months 3 doses (6, 10, 14wks) 7-11 months- 2 doses & booster after 1yr 12-23 months-2 doses >24mnths single dose
Not recommended for >59 months of age
No revaccination recommended
Side-effects: Redness, tenderness, swelling ,fever, loss of appetite, irritability, drowsiness
Contraindications: Allergic reaction to 1st dose, Severely ill Efficacy of upto 57 % for cases of otitis media by serotypes represented in the vaccine
is reported.
PNEUMOCOCCAL VACCINE CONT… The Gambia Pneumococcal Vaccine Trial:
A Phase III trial of the vaccine involving 40 000 people was completed in South Africa
in 2002, and
Phase III trial with 17 437 subjects was concluded in the Gambia in 2004
9-valent vaccine (PCV7+ 1 & 5)
77% effective in preventing pneumococcal infections
16% decrease in child mortality
New 10-valent pneumococcal vaccine:
“Synflorix” developed by GSK
Additional 3 serotypes to PCV7- 1, 5, 7F
Conjugated to protein D of Non Typable H.Influenza (NTHi)
GSK received European Commission authorisation on 31st March 2009
PNEUMOCOCCAL VACCINE - INDIA
Actual burden of pneumococcal disease in India- not known.
Currently available seven-valent conjugate vaccine (PCV-7) covers strains
attributable to approximately 50% burden of S. pneumoniae in India.
The steps needed for inclusion of these vaccines in UIP:
The burden of disease studies for S. pneumoniae Evidence generation and cost effective analysis studies for vaccine The support and advocacy for vaccine research to incorporate
strains which are prevalent in India The preparation of a decision making tool to introduce new vaccines
in UIP.
WHO POSITION
WHO considers that pneumococcal conjugate vaccine should be a priority for inclusion in national childhood immunization programmes.
Countries with mortality among children aged <5 years of >50 deaths/1000 births or with more than 50 000 children’s deaths annually
should make the introduction of PCV-7 a high priority for their immunization programmes.
CHOLERA VACCINE:
Vaccine Killed whole-cell vaccine DUKORAL, 2004 (cholerae 01 in combination with recombinant B-sub unit of cholera toxin)
Indications/Age Travellers , Aid workers assisting in disaster relief or refugee camps, travelling to remote regions with limited access to medical care, risk travellers with underlying gastrointestinal illness or immune suppression >2yrs of age
Dose & route 2 doses orally
Schedule 1wk apart 3 weeks before departure
Side effects None
Contraindications Hypersensitivity to previous dose
Protection (85–90%) protection for 6 months after the second dose. Protection declines rapidly in young children after 6 months, but remains as high as 62% in adult vaccine recipients.
CHOLERA VACCINE:
Vaccine Shanchol and mORCVAXThe closely related bivalent oral cholera vaccines based on serogroups O1 and O139.
Indications/Age Above 1 years of age
Dose & route Orally, 2 doses
Schedule 2 liquid doses 14 days apart
Protection protective efficacy of the vaccine for all ages after 2 doses is 66%licensed in 2009 as mORCVAX in Viet Nam and as Shancholin India; mORCVAX is currently intended for domestic use in Viet Nam, whereas Shanchol will be producedfor Indian and international markets.
WHO POSITION
Cholera control should be a priority in areas where the disease is endemic.
Given the availability of 2 oral cholera vaccines and data on their efficacy, field effectiveness, feasibility and acceptance in cholera-affected populations,
immunization with these vaccines should be used in conjunction with other prevention and control strategies in areas where the disease is endemic and should be considered in areas at risk for outbreaks.
Rotavirus vaccine:
Vaccine Rotarix™ vaccine(The monovalent human ) 2007
RotaTeq™ vaccine(pentavalent bovine–human) 05-06
Indications/Age
Infants 2 and 4 months of age. Infants2, 4 and 6 months of age
Route Orally 2 doses Orally 3 doses
Schedule 1st dose at 6wks & 2nd at 16wks.Interval bet 2doses at least 4wks
1st dose at 6-12wks and 2nd,3rd doses at an interval of 4-10wks
Side effects Mild & transient symptoms of gastrointestinal or respiratory tract
Mild & transient symptoms of gastrointestinal or respiratory tract
Contra indications
Hypersensitivity, history of intussusception or intestinal malformations AGE febrile illness
Hypersensitivity, history of intussusception or intestinal malformations AGE, febrile ill
ROTAVIRUS VACCINES: INDIA
A vaccine based on Indian neonatal strains: clinical trials.
RotarixTM (GSK) -now available in India A monovalent attenuated human rotavirus vaccine Human rotavirus strain 89-12 grown in vero cells and contains the G1P1 [8] strain Lyophilized vaccine The vaccine and the diluents should be stored at 2 to 8° C and must not be frozen. Administer promptly after reconstitution as 1 ml orally.
The first dose can be administered at the age of 6 weeks (no later than at the age of 12 weeks.)
The interval between the 2 doses - at least 4 weeks. The 2-dose schedule should be completed by age 16 weeks, (no later than by 24 weeks of age.)
WHO POSITION
included in all national immunization programs, especially in countries with high death rates, such as those in South and South-eastern Asia and Sub- Saharan Africa.
the age restriction should be removed in countries where disease burden is high and delays in vaccinations and deaths from rotavirus are common.
low risk of intussusception from rotavirus vaccination (about 1 to 2 per 100,000 infants vaccinated),
TYPHOID VACCINES
Indications:
1. Travelers going to endemic areas who will be staying for a prolonged period of time,
2. Persons with intimate exposure to a documented S. typhi carrier
3. Microbiology laboratory technologists who work frequently with S. typhi
4. Immigrants
5. Military personnel
TYPHOID VACCINES
Two types:
1. Injectable Typhoid vaccine
(TYPHIM –Vi,TYPHIVAX)
2. The live oral vaccine (TYPHORAL)
TYPHOID VACCINE CONT… Injectable Typhim –Vi
1. This single-dose injectable typhoid vaccine, from the bacterial capsule of S. typhi strain of Ty21a.
2. This vaccine is recommended for use in children over 2 years of age.
3. Sub-cutaneous or intramuscular injection
4. Efficacy : 64% -72%
TYPHOID VACCINE CONT…
Typhoral vaccine:
1. live-attenuated-bacteria vaccine manufactured from the Ty21a strain
of S. typhi.
2. The efficacy rate of the oral typhoid vaccine ranges from 50-80%
3. Not recommended for use in children younger than 6 years of age.
4. The course consists of one capsule orally, taken an hour before food
with a glass of water or milk (1stday,3rd day &5th day)
5. No antibiotic should be taken during this period
6. Immunity starts 2-3 weeks after administration and lasts for 3 years
7. A booster dose after 3 years
WHO POSITION Typhim –Vi and Typhoral vaccines provide appreciable levels of
protection and have a good record of safety, improved vaccines against typhoid fever are desirable.
vaccines should confer higher levels and more durable protective immunity in all age groups, including those aged <2 years, preferably without the need for booster doses.
HEPATITIS AType of vaccine Inactivated (killed)
Number of doses Two 0.5ml i.m. Second dose 6–24 months after the first
Booster May not be necessary
Contraindications Hypersensitivity to previous dose
Adverse reactions Mild local reaction of short duration, mild systemic reaction
Before departure Protection 2–4 weeks after first dose
Recommended All non-immune travellers to endemic areas
HEPATITIS A VACCINES: INDIA
India: > one billion population over-crowded living conditions and lack of proper sanitation and education, Hepatitis A continues to be a very frequent infection.
HAV infection produces lifelong immunity to hepatitis A, Based on recent studies (Pune, Mumbai, Delhi Chennai) children specially
from low socio-economic category continue to be almost universally exposed to HAV.
Thus, at present, Indian population does not qualify for immunization with hepatitis A vaccine.
WHO POSITION
Highly endemic countries: HAV infects virtually all young children, without causing symptoms but effectively protecting the population against symptomatic hepatitis A disease in later life. In such countries, large-scale hepatitis A vaccination is not required.
Intermediate endemic countries where a relatively large proportion of the adult population is susceptible to HAV, and where hepatitis A represents a significant public health burden, large-scale childhood vaccination may be considered as a supplement to health education and improved sanitation.
Low endemic countries: indicated for individuals with increased risk of contracting the infection.
HAV be integrated into the national immunization schedule for children aged ≥1 year if indicated on the basis of incidence of acute hepatitis A, change in the endemicity
from high to intermediate, and consideration of cost effectiveness.
COMBINED HEPATITIS A AND HEPATITIS B VACCINE
2001- FDA
Twinrix (GlaxoSmithKline)
The vaccine is administered in a three-dose series at 0, 1, and 6 months
Twinrix is approved for persons aged ≥18 years with indications for both hepatitis A and hepatitis B vaccines.
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.
Long-term travellers living in close contact with the indigenous population may be at greater risk of infection.
Vaccines: - Polysaccharide vaccine
- Conjugate vaccine
CONTINUATION……………
Polysaccharide vaccines:bivalent (A and C) or tetravalent (A, C, Y and W-135)One dose, provides protection for 3–5 years Vaccine should be given 2 weeks before departureChildren under 2 years of age are not protected by the vaccineTravellers should opt (A, C, Y, W-135) than the bivalent vaccine
Conjugate vaccine: Monovalent serogroup C conjugate vaccines licensed for use since 1999 incorporated in national vaccination programmes in an increasing number
of countries. prolonged duration of protection in infants who are vaccinated at 2, 3 and 4
months of age.
WHO POSITION
WHO recommends that countries with high (>10 cases/100 000 population/year) or intermediate endemic rates (2–10 cases/100 000 population/year) of
invasive meningococcal disease and countries with frequent epidemics
In these countries, the vaccine may be administered through routine immunization programmes, supplementary immunization activities (SIAs), during outbreaks, or through private vaccination services.
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 States 2 doses 4–8 weeks apart, are recommended for adolescents and adults.
VARICELLA VACCINE CONT… 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.
WHO POSITION These position papers are concerned primarily with the use of vaccines
in large-scale immunization programmes.
Limited vaccination for individual protection, as executed mostly in the private sector, may be a valuable supplement to the national programmes, but is not emphasized in this policy document.
MMR VARICELLA VACCINE (MMRV) Vaccination schedule and use- 12 months- 12 yrs of age 1st dose as early as possible after 12 months of age, 2nd after at least 3 months
interval Post-exposure prophylaxis within 3 days
Adverse reactions- Fever, measles like rash 5-12 days after vaccination, febrile seizures ( risk
higher than MMR and Varicella given separately)
Storage- Very fragile, -15°C Never at room temp.or refrigerator Diluent (sterile water) - refrigerator or room temp.
HUMAN PAPILLOMA VIRUS VACCINE
Vaccine Quadrivalent vaccine (2006)VLPs for 6,11,16,18
Bivalent vaccine (2007)VLPs for 16,18
Indications Young adolescent girls as young as 9 years & prevention of anogenital warts in females & males
Young adolescent girls as young as 10 years
Dose &route 0.5ml IM 0.5ml IM
Schedule 0, 2 & 6 months. minimum 4 wks interval bet 1st & 2nd &12 wks bet 2nd&3rd
0, 1 & 6 months.2nd dose bet 1 and 2 ½ months after the 1st dose.
Side effects Mild and transient local reactions at the site of injection i.e erythema, pain or swelling
same
Contraindications
severe allergic reactions to previous dose, severe acute illness, pregnant females
same
Protection 70% against cervical cancers 70% against cervical cancers
WHO POSITION
HPV vaccination should be introduced into national immunization programmes where prevention of cervical cancer is a public health priority,
the introduction is programmatically feasible and economically sustainable, and
where cost-effectiveness aspects have been duly considered.
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 practiced)
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.
JAPANESE ENCEPHALITIS VACCINES
Currently, three types of JE vaccines in use:
1. Mouse brain-derived inactivated vaccine.2. Cell culture-derived inactivated vaccine and3. Cell culture-derived live attenuated vaccine.
No JE vaccine- WHO-prequalified
The Mouse Brain-derived Inactivated Vaccine: (MBD)
Produced in several Asian countries including India (Central Research Institute, Kasauli). So far, the only type of JE vaccine that is commercially available in
the international market. Safe, efficacious
JAPANESE ENCEPHALITIS VACCINES CONT….
Disdvantages of the MBD vaccine
Multiple doses ( 3 Primary + Booster) Expensive vaccine, complicated schedule, side effects Low availability - Production stopped by major manufacturers globally - CRI may also close down the production
Cell-culture-derived inactivated vaccine
Manufactured in China Based upon the Beijing P-3 strain High viral yields when propagated in primary hamster kidney cells. Formalin-inactivated vaccine, inexpensive
JAPANESE ENCEPHALITIS VACCINES CONT…
Cell-culture-derived live attenuated vaccine 1988 Chinese vaccine based on a stable neuro-attenuated strain of the JE virus (SA-14-14-2). Licensed for use in South Korea, Nepal and Sri Lanka. Vaccination schedule- 2 doses administered 12 months apart in children aged 1–2 years and a booster at 6
years of age > 6 yrs- single dose
Immunogenicity- Children 6-7 years- single dose & Older children- immunized twice at intervals of one to three months: Ab - 83%–100%
Modest reduction in both seroconversion and Ab titre when measles vaccine co-administered with JE vaccine
JAPANESE ENCEPHALITIS VACCINES CONT… October 04, 2013, India’s first indigenously prodcued vaccine against Japanese
Ence.phalitis (JE).
National Institute of Virology, Indian Council of Medical Research and Bharat Biotech Ltd. jointly developed the vaccine— JENVAC-- under the public-private-partnership.
To begin with, the programme will focus on five worst affected states— Assam, Bihar, Tamil Nadu, Uttar Pradesh and West Bengal.
be administered free of cost under the National Immunization Programme.
The vaccine, developed by Bharat Biotech, will be more expensive than the Chinese option.
The imported vaccine costs around Rs.20 per dose while Jenvac is likely to be priced around Rs.70 per dose.
WHO POSITION
With increasing availability of efficacious, safe and affordable vaccines, JE immunization should be integrated into the EPI programmes in all areas where JE constitutes a public health problem.
The most effective immunization strategy in JE-endemic settings is one time catch-up campaigns including child health weeks
SWINE FLU VACCINE/ PANDEMIC INFLUENZA A (H1N1) VACCINES:
INFLUENZA VACCINES 2 Types: Inactivated And Live Attenuated
Inactivated Vaccine: 2009-2010 influenza season (25th Feb. 2009) Trivalent Inactivated Vaccine (TIV): - Type A/Brisbane/59/2007 (H1N1) - Type A/Brisbane/10/2007 (H3N2) - Type B/Brisbane/60/2008
Indications – All children 6 months to 18 yrs > 50 yrs of age Long term hospital stay Pregnant women High risk e.g. aspirin therapy, chronic diseases,
haemoglobinopathies, immunosuppression, compromised resp.function
INFLUENZA VACCINES CONT… Vaccination schedule-
Northern hemisphere- December – MarchSouthern hemisphere- April - September TIV effective if given 2-4 months before exposure 6 months – 9 yrs: 2 doses 1 month apart, annually > 9 yrs – 1 dose annually
Dose and route of administration- 0.25 ml – paediatric and 0.5 ml – adults Intramuscular injection
Efficacy – varies with age, health status, similarity between vaccine strains with circulating strains
INFLUENZA VACCINES CONT… LIVE ATTENUATED INFLUENZA VACCINE (LAIV) 2003- USFDA Same 3 strains as TIV Temperature sensitive, cold adapted Replicate effectively in the mucosa of nasopharynx Efficacy- 87 % efficacy against culture confirmed influenza 27 % decrease in febrile otitis media Can be given anytime in influenza season Dose and route of administration- 5-8 yrs- 2 doses at least 6 wks apart 9-49 yrs- single dose 0.5ml Intranasal route, half dose in each nostril
INFLUENZA VACCINES CONT…
Adverse reactions-
Local- Swelling, erythema, induration Systemic- (not common) fever, chills, myalgia, rarely anaphylaxis
Contraindications - Severe allergic reaction to prior dose, Acute moderate to severe illness
Storage: 2 °C and 8 °C Must not be frozen Opened multidose vials – till expiry date
WHO POSITION Pregnant women should have the highest priority.
Additional risk groups to be considered for vaccination, in no particular order of priority, are children aged 6–59 months, the elderly, individuals with specific chronic medical conditions, and health-care workers.
Countries with existing influenza vaccination programmes targeting any of these additional groups should continue to do so and should incorporate immunization of pregnant women into such programmes.
Vaccines on clinical trials
MALARIA VACCINES
World’s most important parasitic disease No vaccine currently licensed for malaria
Challenges – Complex malarial parasite life cycle Each stage- immunologically distinct Perception- limited market potential
Asexual stage vaccines- Based on the Ag of Pf in man Reduce severe complicated malaria- ↓mortality and morbidity So, WHO research priority vaccinese.g. Synthetic Pf (Pfs) conjugate vaccines (Pfs 66) Recombinant protein based
vacines
MALARIA VACCINES CONT…
Sexual stage vaccines- Transmission blocking vaccines e.g. Pfs 25 conjugate vaccine
Pre-erythrocytic stage vaccines- Pre clinical stage
e.g. radiation attenuated sporozoite vaccines, polypeptide
DNA vaccines, circumsporozoite (CS) protein vaccines
VERY YOUNG TAKEN FOR TRAILS IN VIEW OF HIGH MORTALITY AND MORBIDITY
Phase III trial will demonstrate how the vaccine performs in two groups of children—one aged 6 to 12 weeks and a second aged 5 to 17 months—in different transmission settings across a wide geographic region in Africa.
MALARIA VACCINE POSSIBLE IN NEXT FEW YEARS
In Phase II testing, the vaccine reduced cases of malaria in young children 5 to 17 months by 53%.
If Phase III results are as good, the vaccine could be fully available in the next 5 - 10 years.
DENGUE VACCINES
4 types of dengue vaccines under clinical trials: Live tetravalent dengue vaccine Intertypic Chimeric vaccine (infectious clone technology) Chimeric vaccine Recombinant DNA vaccine
Intertypic chimeric vaccine- Structural genes from the DNA copy of an attenuated strain of dengue virus is replaced by the corresponding genes of a different dengue virus
serotype
Chimeric vaccine- Infectious clone technology Replaces the E gene of the 17D yellow fever (YF) vaccine with the analogous gene of the vaccine-targeted flavivirus
DENGUE VACCINES: CURRENT STATUS (2008)
HIV / AIDS VACCINES
Challenges for vaccine development:• Viral Genetic Diversity: HIV is not just one specific virus.• Immune Protection: We don’t know what immune responses are needed, or how
strong they need to be.• Neutralizing Antibody: Difficult to generate broadly neutralizing antibodies.• Vaccine Testing: Slow process, very expensive• Transmitted by mucosal route & infected cells• Time consuming & costly clinical trials
Vaccine approaches in development:
Subunit vaccine, Recombinant vector vaccine, Vaccine combination, Peptide
vaccine, Virus-like particle vaccine (pseudovirion vaccine), Plasmid DNA
vaccine (nucleic acid vaccine), Whole-inactivated virus vaccine, Live-attenuated
virus vaccine
AIDS VACCINES CURRENTLY IN CLINICAL TRIALS
Subunit Vaccines
- Recombinant envelope protein: gp 160, gp 120
- Peptide: V3 peptide, T-B peptide
Live vector-based vaccines
- Vaccinia envelope
- Canarypox envelope
DNA vaccines
HIV / AIDS VACCINES CONT.. Preventive vaccines
Designed for people who are not infected with HIV If effective, would reduce risk of infection or viral load set
point after infection
Therapeutic vaccinesDesigned for people who are living with HIV If effective, would use the body’s immune system to help
control or clear HIV in the body
Luc Montagnier on Vaccine for AIDS
Our goal is not to completely eradicate the infection - that would be very difficult - but to produce a vaccine that will prevent not infection but disease. I think this is more possible.
It's clear that prevention will never be sufficient. That's why we need a vaccine that will be safe.
THE NEW GMO SWINE FLU CORN FLAKES Iowa State University
researchers are putting flu vaccines into the genetic makeup of corn, which may someday allow pigs and humans to get a flu vaccination simply by eating corn or corn products.
REFERENCES
Weekly Epidemiological Records http://www.who.int/wer Vaccines update, www.cdc.gov www.gavialliance.com Arora, Textbook of Microbiology, 3rd Edn. New generation vaccines, levine & woodrow Vaccines , Plotkin Summary papers of Global Immunization Meeting New York, 17-19 Feb 200 Dengue Vaccine: The Current Status Maj MS Mustafa*, Lt Col VK Agrawal MJAFI 2008; 64 : 161-164
Albert Einstein said:“ We cannot solve today’s problems with the same
level of thinking that we were at when we created them.”
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