Epivac Pink Book Netconference

EpiVac Pink Book Netconference

Polio and Hib- 2017

MODERATOR: Welcome to the EpiVac Pink Book Webinar Series-Netconference Series. I am Andrew Kroger; I’m a Medical Officer in the Immunization Services Division, of the National Center for Immunization and Respiratory Diseases, or NCIRD, at the CDC. I will be the moderator for today’s session. Here are the learning objectives: at the conclusion of this session, the participant will be able to describe the different forms of immunity; describe the different types of vaccines; for each vaccine-preventable disease, identify those for whom routine immunization is recommended; for each vaccine-preventable disease describe characteristics of the vaccine used to prevent the disease; describe an emerging immunization issue; locate resources relevant to current immunization practice andimplement disease detection and prevention health care services, for example, smoking cessation, weight reduction, diabetes screening, blood pressure screening and immunization services to prevent health problems and maintain health. Today is August30th and we have Dr. Raymond Strikas, a Medical Officer with CDC/NCIRD to present today’s topic, polio and Haemophilus influenzae type b or Hib as discussed in the CDC textbook, Epidemiology and Prevention of Vaccine-Preventable Diseases, also known as the Pink Book, whose 13th Edition was published in 2015. Continuing Education or CE credit is available only through the CDC ATSDR Training and Continuing Education Online System at www2a.cdc.gov/TCEOnline. If you are watching this versionlive, the course number is WC2645-083017.If you are watchingan enduringor archivedcourse, the course number is WD2645-083017. CE credit for the live course expiresOctober 2nd, 2017. CE credit for the archived course expires June 1st, 2018. Instructions are available in the resource pod. Note that a verification code is no longer required. In compliance with Continuing Education requirements, all presenters must disclose any financial or other associations with the manufacturers of commercial products, suppliers of commercial services or commercial supporters, as well as any use of unlabeled products or products under investigational use. CDC, our planners, content experts and their spouses or partners wish to disclose they have no financial interest or other relationships with the manufacturers of commercial products, suppliers of commercial services or commercial supporters. Planners have reviewed content to ensure there is no bias. Presentations will not include any discussion of the unlabeled use of a product or a product under investigational use. CDC does not accept any commercial support. If you have a question during this presentation, please enter your question into the QA pod.I will collect these questions during the presentation and then we will address them during the Question and Answer period, which will follow Dr. Strikas’ presentation. So I will now turn the microphone over to Dr. Strikas, you may begin.

RAYMOND STRIKAS: Thank you Dr. Kroger and good day everyone. It’s a pleasure to present to you from Atlanta. Our topics today, as you heard, are polio and polio vaccine, followed by Haemophilus influenzae type b bacteria and disease and Hib vaccine. I’m going to start with polio and polio vaccine. If you’re following along in the 13th Edition of the Pink Book, the slides I’m using are similar to the ones in chapter 18, which begins on page 297. Records from antiquity mention crippling diseases that are consistent with poliomyelitis. The first outbreaks in Europe were reported in the early 19th Century and outbreaks were first reported in the United States in 1843. Then, for the next 100 years, polio epidemics were reported from developed countries in the Northern Hemisphere each summer and fall. Polio reached a peak in the United States in 1952 with more than 21,000 paralytic cases. Once effective vaccines were introduced in the mid-1950s, polio incidence declined rapidly. This is a photograph of a ward filled with Emerson Iron Lungs. These were negative pressure ventilators that enabled a person to breathe when their normal muscle control had been lost due to infection with the poliovirus. If you are ever in Atlanta, we have one of these in our Global Health Odyssey Museum. It was donated by the family of a patient who used the device in the late 1950s until his death in 2003. Poliomyelitis is a disease that few health care providers in the United States have or will ever see since wild type poliovirus transmission was interrupted in the United States almost 40 years ago in 1979. Poliomyelitis is caused by an enterovirus. There are three distinct serotypes of poliovirus, 1, 2 and 3; WPV on the slide indicates the abbreviation for wild poliovirus. Now there is minimal heterotypic immunity between serotypes, which means that immunity to one serotype does not protect you very much from the other serotypes. That is why there are three viruses in the vaccine. The virus initially enters through the mouth, as you see on this graphic, and then replicates or multiplies in the pharynx and GI tract. The virus is usually present in the throat and in the stool before the onset of symptoms and continues to be excreted in the stool for several weeks. The virus invades local lymphoid tissue, enters the bloodstream, and then it may infect cells of the central nervous system. When the virus replicates in motor neurons or nerve cells of the interior horn of the spinal cord in the brain stem, it destroys cells and causes the typical symptoms of polio. Up to 72% of all polio infections, as demonstrated by the large bar on the left, in children, are asymptomatic. Infected persons without symptoms still shed virus in the stool and are able to transmit the virus to others. About 24% of polio infections in children consist of a minor, non-specific illness without clinical or laboratory evidence of central nervous system involvement, the second bar on the graph. Non-paralytic aseptic meningitis occurs in 1% to 5% of polio infections in children. Symptoms of neck, back and/or leg stiffness can last 2 to 10 days and are followed by complete recovery. Fewer than 1%, some estimate 1 per 1,000 of all polio infections in children, result in flaccid paralysis. Many persons recover completely and muscle function returns to some extent in most persons who have paralytic polio. In general, the severity of polio increases with age and older children and adults are more likely to be paralyzed or die than infants. Spinal polio is the most common type of paralytic polio. From 1969 to 1979, 79% of paralytic cases were spinal polio, as you see in this picture, as characterized by asymmetric paralysis that most often involves the legs or one leg. Humans are the only known reservoir of poliovirus, which is transmitted most frequently by persons with inapparent infections, that is the infected person does not have any recognizable signs and symptoms. Person-to-person spread of poliovirus by the fecal-oral route is the most important route of transmission, although the oral-oral route is possible. Poliovirus is highly infectious, with seroconversion rates among susceptible household contacts of children nearly 100% and greater than 90% among susceptible household contacts of infected adults. Persons infected with poliovirus are most infectious from 7 to 10 days before and after the onset of symptoms, but poliovirus may be present in the stool for up to three to six weeks. Poliovirus infection typically peaks in summer months in temperate climates and there is no seasonal pattern in tropical climates. This graph demonstrates in the pre-vaccine era infection with wild poliovirus was common worldwide; these data are for the United States. The incidence of polio in the U.S. decline rapidly after the licensure of inactivated polio vaccine, abbreviated IPV, in 1955 and live oral polio vaccine, abbreviated OPV, in the 1960s. The last cases of paralytic polio caused by endemic transmission of wild virus in the United States were in 1979 when an outbreak occurred among Amish populations in several Midwest states. The virus in those outbreaks was imported from the Netherlands. From 1980 through 1999, 162 confirmed cases of paralytic polio were reported. This was an average of eight cases per year. Six of these 162 cases were acquired outside the United States and imported. The last imported case was reported in 1993. Two of the cases were classified as indeterminate, meaning no poliovirus was isolated from samples obtained from the patients and the patients had no history of recent vaccination or direct contact with a vaccine recipient. The remaining 154 cases were vaccine associated paralytic polio or VAPP, commonly called VAPP, caused by live oral polio vaccine. Since 2000, the U.S. has exclusively used the inactivated polio vaccine, IPV, so the last case of VAPP acquired in the United States was reported in 1999. In 2005, the single case you see on the graph was an unvaccinated U.S. adult infected with polio vaccine virus in Costa Rica, who subsequently developed VAPP. A second case of VAPP from a vaccine-derived poliovirus in a person with longstanding immunodeficiency was reported in 2009. The patient was probably infected approximately 12 years prior to the onset of paralysis, demonstrating the length of time the virus can exist in a person with immunodeficiency. Inactivated poliovirus was licensed in 1955 and was used extensively until the early 1960s. In 1963, trivalent oral polio vaccine or OPV was licensed and, for the most part, replaced IPV use. Trivalent OPV became the vaccine of choice in the U.S. and most other countries after its introduction. An enhanced-potency inactivated poliovirus vaccine, which we’ll refer to as simply IPV, was licensed November 1987. To eliminate VAPP from the U.S., the Advisory Committee on Immunization Practices or ACIP recommended in 2000 that IPV be used exclusively in the U.S. The U.S. discontinued use of OPV in 2000. IPV is highly effective in producing immunity to the three types of poliovirus it contains. Like many other inactivated vaccines, most recipients do not become immune after a single dose, but 90% of recipients are immune to all three poliovirus types after two doses and at least 99% are immune after three doses. The duration of immunity with IPV is not known, although, it probably provides lifelong immunity after a complete series. The figure here shows the Recommended Childhood Immunization Schedule for 2017 and outlines the recommended IPV series for children. We’ve blown that figure up here to show the IPV schedule, a primary series of IPV consists of three doses. The first dose may be given as early as six weeks of age, but is usually given at two months of age with a second dose at four months of age. The third dose should be given between 6 and 18 months of age. The recommended interval between the primary series doses is two months. However, if accelerated protection is needed, the minimum interval between each of the first three doses of IPV is four weeks. The final dose in this series, the fourth dose, should be administered on or after the fourth birthday and at least six months after the previous dose. In the first six months of life, minimum age and minimum intervals are only recommended if the person is at risk of eminent exposure to circulating poliovirus, that is, travel to a polio endemic region or during an outbreak. If four or more doses are administered before age four years, an additional dose should be administered at four to six years of age, just make sure there was a six month interval between the next to the last and the last dose. If a third dose is given on or after the fourth birthday and at least six months after the previous dose, then a fourth dose of IPV is not necessary. Now let’s talk about schedules that include both IPV and OPV and this is relevant particularly to people, particularly children, who immigrate to the United States. Now, as we said, only IPV is available in the United States, if both OPV and IPV were administered as part of a series, the series should be completed with IPV. Any combination of four doses of OPV and IPV by four to six years of age constitutes a complete series. If only OPV were administered and all doses were given prior to four years of age, one dose of IPV should be given at four years or older, at least six months, which is different than our previous recommendation of four weeks, but at least six months after the last OPV dose. Please note, with the 2017 Childhood Immunization Schedule, CDC stated, previous poliovirus vaccination is valid if documentation indicates receipt of IPV or trivalent OPV, commonly abbreviated tOPV; tOPV was used for routine poliovirus vaccination before April 1st, 2016 in all OPV using countries outside the U.S. Therefore, if a child has documentation of receipt of an OPV dose rather than tOPV before April 1, 2016, this can be taken to represent a tOPV dose and should be counted towards the U.S. vaccination schedule, unless there is a specific notation that it was administered during a vaccination campaign. Vaccination campaigns commonly used bivalent OPV, in some cases monovalent OPV, so that’s when you would need to see tOPV to be sure it was that product. Consistent with the polio eradication strategy, doses of OPV administered on or after April 1st, 2016 are either bivalent OPV or monovalent OPV, abbreviated bOPV and mOPV, which are used in campaigns and/or an outbreak response. Those doses of either bivalent OPV or monovalent OPV do not count towards the U.S. vaccination requirements for protection against all three poliovirus types. So persons age less than 18 years with doses of OPV that do not count towards the U.S. vaccination requirements should receive IPV to complete the schedule according to the U.S. IPV schedule. All of this information is discussed in footnotes and adjuncts to the U.S. 2017 Immunization Schedule. There are five poliovirus containing vaccine products available in the United States. One is a single component IPV vaccine, the trade name is IPOL, I-P-O-L. Additionally, there are four polio containing combination vaccine products and I’ll discuss each of those individually. Pentacel is produced by Sanofi Pasteur and contains DTaP, Hib vaccine and IPV. It is approved for the first four doses of the component vaccines among children six weeks through four years of age. Pentacel is not approved for children five years or older. This vaccine must be reconstituted prior to administration. The DTaP IPV diluent must be mixed with the lyophilized Hib component that is freeze-dried Hib component to create DTaP-IPV/Hib vaccine. Pediarix is produced by GlaxoSmithKline and contains DTaP, hepatitis B and IPV vaccines. It is approved for the first three doses of the IPV series among children six weeks through six years of age. There are two DTaP and IPV combination vaccines, Kinrix and Quadracel. Kinrix is approved only for the fifth dose of DTaP and the fourth dose of IPV among children four through six years of age. Quadracel is approved only for the fourth or fifth dose of DTaP and the fourth dose of IPV among children four through six years of age. Neither Kinrix nor Quadracel should be used to reconstitute the Hib component of Pentacel vaccine. Routine vaccination of U.S. residents 18 years of age and older is not necessary or recommended because most are already immune and have a very, very small risk of exposure to wild poliovirus in the United States. Some adults, however, are at increased risk of infection with poliovirus and these include travelers to areas where poliomyelitis is endemic or epidemic and laboratory workers handling specimens that may contain polioviruses. Recommendations for poliovirus vaccination of adults, at increased risk, depend upon the previous vaccination history and the time available before protection is required. For unvaccinated adults, including adults without a written record of prior polio vaccination, at increased risk of exposure to poliomyelitis primary immunization of IPV is recommended. The recommended schedule is two doses separated by one to two months and a third dose given 6 to 12 months after the second dose. The minimum interval between the second and third dose is six months. Adults who’ve previously completed a primary series of three or more doses and who are at increased risk of exposure to poliomyelitis should receive one dose of IPV prior to encountering risk. The need for further supplementary doses has not been established. Only one supplemental dose of polio vaccine is presently recommended for adults who have received the complete series. And it is not necessary to administer additional doses for subsequent travel to a polio endemic country. Adults who have previously received less than a full primary course of OPV or IPV and who are at increased risk of exposure to poliomyelitis should be given the remaining doses of IPV, regardless of the intervals since the last dose and type of vaccine previously received. It is not necessary to restart the series of either vaccine if the schedule has been interrupted. Severe allergic reactions such as anaphylaxis to a vaccine component or following a prior dose of vaccine is a contraindication to further doses of that vaccine, including IPV in this case. Now, because IPV vaccine contains trace amounts of streptomycin, neomycin and polymyxin B, which are all antibiotics, there is a possibility of allergic reactions in persons who are sensitive to these antibiotics. Persons with allergies that are not anaphylactic, such as skin contact sensitivity, may be vaccinated. Persons with a moderate or severe acute illness normally should not be vaccinated until their symptoms have improved, which is true of all vaccines including IPV. Minor local reactions such as pain or redness are the most common reactions occurring IPV and they are uncommon, occurring in less than 3% of patients in the data we have. Severe reactions are rare. As stated before, the last documented indigenous transmission of wild poliovirus in the United States was in 1979. In September 1994, an international commission certified the Western Hemisphere was free of indigenous wild poliovirus. The last isolation of wild poliovirus type 2, anywhere in the world, was in India in October 1999 and therefore, we believe poliovirus type 2, wild poliovirus type 2, has been eradicated. The number of worldwide reported cases as you see in the graphics from 1988 to 2015 has decreased from an estimated 350,000 cases in 1988 and for, through 2017, through about August 9th, we’ve only had reports of eight wild poliovirus cases, five of those cases in Afghanistan, three cases in Pakistan and to that date, Nigeria, which had had some cases in the recent past, was polio-free. There was a switch from trivalent OPV to bivalent OPV in April of 2016, this was the first step to phasing out the use of all OPV and many countries have moved from OPV to IPV to limit the risk of VAPP or that is, vaccine-derived poliomyelitis. The Polio Eradication and Endgame Strategic Plan of 2013 to 2018 calls for a transition in the vaccines used to eradicate polio and requires the removal of all oral polio vaccines or OPVs in the long-term. And again, this will eliminate the rare risks of vaccine associated paralytic polio, VAPP, and circulating vaccine derived poliovirus, commonly abbreviated cVDPV. Additional resources you see on this page for polio eradication are at cdc.gov/polio and there is additional information about polio infection and vaccines at the website you see on the lower part of the slide.