NEW VACCINES IN THE OFFICE Amin Thalji M.D. Ramallah ,Palestine Pediatric society conference April 2011
A smart quote You are never strong enough that you don't need help --Cesar Chavez, Mexican-American labor leader and civil rights activist, quoted for his birthday, March 31, 1927
NEW VACCINES IN THE OFFICE • Pneumococcal vaccines • Hepatitis A vaccine • Rotavirus vaccines • Varicella vaccine • Cost ?
Streptococcus pneumoniae A century ago • Sir William Osler Pneumococcus “the captain of all the men of death” Today • Severe community-acquired pneumonia Most common cause of death in developed countries • Worldwide: 1.2 million infant deaths every year
S. Pneumoniae • Gram stain: • Gram positive diplococci • 91 Serotypes • Growth Morphology • α-hemolysis on 5% SBA • Biconcave colonies • Mucoid colonies • Capsule
Streptococcus pneumoniae • Serious diseases • Pneumonia • Meningitis • Febrile bacteraemia • less serious manifestations of infection • Otitis media • Sinusitis • Bronchitis
Strep pneumo serotypes • The surface capsular polysaccharide of S. pneumoniae provokes a type-specific protective immune response and serves as the basis for serotyping of these organisms. • More than 90 different pneumococcal serotypes have been identified. Serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F are the most prevalent in children, accounting for between 60 and 80 percent of infections, depending upon the area of the world.
Pneumococcal vaccinesPolysaccharide (pneumovax) and conjugated(PCV) • Polysaccharide vaccines • Not immunogenic in children younger than two years with the highest incidence of invasive disease . • Conjugation of a nonpneumococcal protein to pneumococcal polysaccharides • T cell-dependent memory response • Increases the effectiveness of the vaccine during the first two years of life.
Streptococcus pneumoniae • Recognizing the heavy burden of pneumococcal disease occurring in young children and the safety and efficacy of PCV in this age group, WHO RECOMMENDS • It should be a priority to include this vaccine in national immunization programmes, particularly in countries where mortality among children aged <5 years is >50/1000 live births
Prevenar 3 vs 4 doses WHO POSITION • Efficacy of a 3-dose schedule for infants without a subsequent booster dose in several developing countries. • A schedule compatible with the national immunization programmes in many developing countries. • The benefit of administering an additional dose in the second year of life requires further investigation.
High risk groups ? • The schedule for children in high-risk groups, who are > 24 -71 months of age also includes two doses of pneumovax -the 23-valent polysaccharide vaccine (PPSV23):- • First dose 8 weeks after last PCV and the second dose 5 years later • A second dose of PPSV23 is not recommended for children with cochlear implants.
High risk groups(cont) A single dose of PCV may be administered to children ages 6 through 18 years who are at increased risk for invasive pneumococcal disease (regardless of whether they have previously received PCV and/or PPSV23).
Vaccines with broader serotype coverage? • Once pneumococcal vaccines offering broader serotype coverage become available, countries using PCV-7 should assess whether it would be helpful to switch to these vaccines.
Vaccines with broader serotype coverage? (cont) • This should be based on:_ • The distribution of serotypes causing invasive pneumococcal disease in the affected population and • The likely additional benefit to be gained • The introduction of pneumococcal conjugate vaccines with broader coverage will be facilitated if PCV-7 is already in use
Streptococcus pneumoniaePalestine –West Bank Serotype Distribution and Antibiotic Resistance Profiles of Streptococcus pneumoniae Isolated from Bacteremic Children Residing in Palestine West Bank.“ Kattan R et al.
Streptococcus pneumoniaePalestine –West Bank • Patients population Children < 11 years of age 70.7% less than 2 years • Type of samples Blood cultures • Number of isolates 120 isolates (one isolate per patient) • Geographic location Caritas Baby Hospital 113 isolates(2001-2009) Makassed hospital 7 isolates (2008-2009) Kattan R et al.
PCV7 VS PCV13? • Distribution of S. pneumoniae Serotypes in (PCV13)=80.8% • Distribution of S. pneumoniae Serotypes in (PCV7)=50.8%
S. pneumoniae Resistance patterns to antibiotics-West Bank • Penicillin (Disk Diffusion 1μg Oxacillin disk) Sensitive:-41.7% Resistant:-58.3% • Cefotaxime (MIC) by E-Test 100% Sensitive • Fluoroquinolones (Disk Diffusion) 100% Sensitive • Vancomycin (Disk Diffusion) 100% Sensitive Kattan R et al.
Conclusions • Serotype 14 is one of the most prevalent and drug resistant serotype in the study population • Our local study supports the utilization of PCV13 pneumococcal vaccine in the national vaccination schedule Kattan R et al.
Recommendations • Appropriate surveillance for pneumococcal disease in order to establish a baseline measurement of disease burden and to monitor the impact of vaccination is recommended. • Colleagues are expected by the ministry of health to report information on PCV recipients in order to take this into account in the surveillance process
PCV Storage/handling • PCV7 or 13 should be stored at 2 to 8ºC. Exposure to freezing causes irreversible loss of potency . PCV7 or 13 that has been frozen should be discarded
Serotype replacement? • Conjugate vaccines could result in a significant shift in prevailing pneumococcal serotypes that cause serious disease. • To date, however, vaccine-induced replacement of prevailing pneumococcal serotypes has not been found to be a significant problem with respect to invasive disease.
A quote I like It is better to debate a question without settling it than to settle a question without debating it --Joseph Joubert, French essayist
Hepatitis A infectionSeroepidemiological studies show that prevalence of anti-HAV antibodies in the general population varies from 15% -100% in different parts of the world
Hepatitis A infection • An acute, usually self-limiting disease of the liver caused by hepatitis A virus(HAV). • Incidence of hepatitis A infection related to socioeconomic development. • Acute liver failure is rare, occurring in fewer than 1 percent of cases.
Hepatitis A Age related clinical presentation • In children aged < 6 years usually asymptomatic, with only 10% developing jaundice. • Infection with HAV induces lifelong immunity.
Hepatitis A vaccination high endemic areas WHO position • In high endemic areas like ours • Infection during childhood • High rate of natural immunity in adolescence and adulthood • large-scale vaccination programmes are not recommended . • What about individual and sporadic vaccination in the office?
Hepatitis A vaccination low to intermediate endemic areas WHO position • Higher percentage of susceptible older children and adults who are more likely to suffer from clinical disease, with jaundice occurring in > than 70% of cases. • Thus large scale childhood immunization as a supplement to health education and improved sanitation is likely to be a cost-effective public health tool to control the disease.
Rotavirus vaccines • Rotaviruses:-The most common cause of severe diarrheal disease in young children throughout the world. • WHO 2004 estimates:- 527 000 children aged <5 years die each year from vaccine preventable rotavirus infections. • Most of these children live in low-income countries
Rotavirus vaccines • Two available oral, live, attenuated rotavirus vaccines :- • Rotarix (RV5)(GlaxoSmithKline Biologicals, Rixensart, Belgium) and • RotaTeq (RV1) (Merck & Co. Inc., West Point, PA, USA), • Both vaccines are considered safe and effective in preventing gastrointestinal disease caused by rotaviruses
Rotavirus vaccine WHO position-October 2009 • Rotavirus vaccine for infants should be included in all national immunization programmes in order to reduce severe rotavirus associated diarrhea and child mortality. • The first dose of either RotaTeq or Rotarix to be administered at age 6–15 weeks. The maximum age for administering the last dose of either vaccines should be 32 weeks.
Rotavirus vaccines and other infant immnunizations • RV5 and RV1 may be administered at the same visit as the other routine inactivated infant immunizations . • In countries where (OPV) continues to be used, WHO suggests RV5 or RV1 and OPV not be administered at the same visit as OPV appears to have an inhibitory effect on the immune response to the first dose of rotavirus vaccine
Whenever possible, the rotavirus vaccine series should be completed with the same vaccine product . • A total of three doses of vaccine should be given to infants who received RV5 for any dose and infants in whom the vaccine product for previous dose(s) is unknown.
RV1 and RV5 are contraindicated in infants with severe combined immunodeficiency • RV1 is contraindicated in infants with a severe (anaphylactic) allergy to latex because the applicator contains latex
Is vaccination all what we need to control Rotavirus disease? In addition to the use of rotavirus vaccines a comprehensive strategy to control diarrheal diseases should include:- improvements in hygiene and sanitation, zinc supplementation, community-based administration of oral rehydration solution and overall improvements in case management.
Varicella • Most healthy children have self-limited infection with primary varicella. • Increased incidence of hospitalization and even mortality in selected groups. • Significant complications:- soft tissue infection, pneumonia, hepatitis, and encephalitis. • Patients at increased risk:- adults, pregnant women, and immunosuppressed hosts.
Varicella vaccine recommendations Children • 2 doses recommended: • 1st dose at age 12-15 months • 2nd dose at age 4-6 years • The recommended minimum interval between the first dose and the "catch-up" second dose is three months for children aged <12 years and four weeks for persons aged >13 years
Varicella vaccine recommendations • Varicella is usually less severe in vaccinated individuals, but these children can still transmit the virus to a susceptible host
Varicella vaccine recommendations • Varicella vaccine is highly recommended in VZV-seronegative adults with ongoing risk of exposure (eg, day care employees, health care workers), those who are household contacts of immunosuppressed hosts, and in women of childbearing age
Varicella vaccine recommendations Pregnancy • Vaccination is not recommended in women who are pregnant or might become pregnant within four weeks of receiving the vaccine. • Pregnant women, without evidence of VZV-specific immunity, should receive the first dose of varicella vaccine upon completion or termination of pregnancy and before discharge from the health care facility. The second dose should be administered four to eight weeks after the first dose
Varicella vaccineContraindications • Live vaccine:- • contraindicated for immunocompromised hosts.
Varicella vaccineContraindications • Varicella vaccine should also not be given to persons who have a family history of hereditary immunodeficiency until the immunocompetence of the potential vaccinee is determined
I hope this does not apply to my presentation! Incomprehensible jargon is the hallmark of a profession --Kingman Brewster Jr., American educator and diplomat