Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309267021
Category : Medical
Languages : en
Pages : 237
Book Description
Vaccines are among the most safe and effective public health interventions to prevent serious disease and death. Because of the success of vaccines, most Americans today have no firsthand experience with such devastating illnesses as polio or diphtheria. Health care providers who vaccinate young children follow a schedule prepared by the U.S. Advisory Committee on Immunization Practices. Under the current schedule, children younger than six may receive as many as 24 immunizations by their second birthday. New vaccines undergo rigorous testing prior to receiving FDA approval; however, like all medicines and medical interventions, vaccines carry some risk. Driven largely by concerns about potential side effects, there has been a shift in some parents' attitudes toward the child immunization schedule. The Childhood Immunization Schedule and Safety identifies research approaches, methodologies, and study designs that could address questions about the safety of the current schedule. This report is the most comprehensive examination of the immunization schedule to date. The IOM authoring committee uncovered no evidence of major safety concerns associated with adherence to the childhood immunization schedule. Should signals arise that there may be need for investigation, however, the report offers a framework for conducting safety research using existing or new data collection systems.
The Childhood Immunization Schedule and Safety
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309267021
Category : Medical
Languages : en
Pages : 237
Book Description
Vaccines are among the most safe and effective public health interventions to prevent serious disease and death. Because of the success of vaccines, most Americans today have no firsthand experience with such devastating illnesses as polio or diphtheria. Health care providers who vaccinate young children follow a schedule prepared by the U.S. Advisory Committee on Immunization Practices. Under the current schedule, children younger than six may receive as many as 24 immunizations by their second birthday. New vaccines undergo rigorous testing prior to receiving FDA approval; however, like all medicines and medical interventions, vaccines carry some risk. Driven largely by concerns about potential side effects, there has been a shift in some parents' attitudes toward the child immunization schedule. The Childhood Immunization Schedule and Safety identifies research approaches, methodologies, and study designs that could address questions about the safety of the current schedule. This report is the most comprehensive examination of the immunization schedule to date. The IOM authoring committee uncovered no evidence of major safety concerns associated with adherence to the childhood immunization schedule. Should signals arise that there may be need for investigation, however, the report offers a framework for conducting safety research using existing or new data collection systems.
Publisher: National Academies Press
ISBN: 0309267021
Category : Medical
Languages : en
Pages : 237
Book Description
Vaccines are among the most safe and effective public health interventions to prevent serious disease and death. Because of the success of vaccines, most Americans today have no firsthand experience with such devastating illnesses as polio or diphtheria. Health care providers who vaccinate young children follow a schedule prepared by the U.S. Advisory Committee on Immunization Practices. Under the current schedule, children younger than six may receive as many as 24 immunizations by their second birthday. New vaccines undergo rigorous testing prior to receiving FDA approval; however, like all medicines and medical interventions, vaccines carry some risk. Driven largely by concerns about potential side effects, there has been a shift in some parents' attitudes toward the child immunization schedule. The Childhood Immunization Schedule and Safety identifies research approaches, methodologies, and study designs that could address questions about the safety of the current schedule. This report is the most comprehensive examination of the immunization schedule to date. The IOM authoring committee uncovered no evidence of major safety concerns associated with adherence to the childhood immunization schedule. Should signals arise that there may be need for investigation, however, the report offers a framework for conducting safety research using existing or new data collection systems.
Vaccines Explained
Author: Laurie Coger
Publisher:
ISBN: 9780615650425
Category :
Languages : en
Pages : 76
Book Description
I see a lot of dogs in my typical workday. Some sick, some healthy, many somewhere in between. I sometimes remember some details about them after their appointments, but there are a few dogs that are forever vividly etched in my memory. This is the case with Lucy, a 4 month old black Labrador mix adopted from a local rescue group. Lucy was my 9:15 appointment on an early fall Saturday morning, over eight years ago. It was a beautiful day, and I was looking forward to meeting a friend for lunch and then spending some time with my own dogs. Lucy had been with her owners a few weeks, and was a typical happy, active puppy. She had received her first vaccination (DAPP) four weeks ago while with her foster family. My physical examination revealed no abnormalities - she appeared completely healthy. So I administered her second DAPP vaccination, which happened to be exactly the same brand and formulation she had received a month ago. Before I could withdraw the needle from her skin, it was apparent that something was very wrong. Lucy stiffened, and then collapsed. I immediately began treatment for this vaccine reaction, and she responded initially. She had her first seizure half an hour later. Over the course of the morning, her seizures progressed, and she stopped responding to the intravenous fluids and drugs we administered. She died at 2:16 PM, just over five hours after she bounced into the hospital, a bright, happy puppy with a tennis ball in her mouth. My purpose in writing this book is to provide a straightforward explanation of what a vaccine is, how it works, and which are (and are not) needed for most dogs. This information is what I want to share with every new puppy owner at his or her first office call (and now that it is in book form I can!). As such, it is intended to be an understandable yet not "dumbed down" explanation of this important medical procedure for every concerned dog owner. You will notice scientific references sprinkled throughout the chapters, as well as in the References section. More technical information is available at the book website, www.VaccinesExplained.com for those interested. My basic vaccination schedule and "Best Practices" for vaccinating are also included. I sincerely hope this guide aids you in making informed vaccine choices for your dog.
Publisher:
ISBN: 9780615650425
Category :
Languages : en
Pages : 76
Book Description
I see a lot of dogs in my typical workday. Some sick, some healthy, many somewhere in between. I sometimes remember some details about them after their appointments, but there are a few dogs that are forever vividly etched in my memory. This is the case with Lucy, a 4 month old black Labrador mix adopted from a local rescue group. Lucy was my 9:15 appointment on an early fall Saturday morning, over eight years ago. It was a beautiful day, and I was looking forward to meeting a friend for lunch and then spending some time with my own dogs. Lucy had been with her owners a few weeks, and was a typical happy, active puppy. She had received her first vaccination (DAPP) four weeks ago while with her foster family. My physical examination revealed no abnormalities - she appeared completely healthy. So I administered her second DAPP vaccination, which happened to be exactly the same brand and formulation she had received a month ago. Before I could withdraw the needle from her skin, it was apparent that something was very wrong. Lucy stiffened, and then collapsed. I immediately began treatment for this vaccine reaction, and she responded initially. She had her first seizure half an hour later. Over the course of the morning, her seizures progressed, and she stopped responding to the intravenous fluids and drugs we administered. She died at 2:16 PM, just over five hours after she bounced into the hospital, a bright, happy puppy with a tennis ball in her mouth. My purpose in writing this book is to provide a straightforward explanation of what a vaccine is, how it works, and which are (and are not) needed for most dogs. This information is what I want to share with every new puppy owner at his or her first office call (and now that it is in book form I can!). As such, it is intended to be an understandable yet not "dumbed down" explanation of this important medical procedure for every concerned dog owner. You will notice scientific references sprinkled throughout the chapters, as well as in the References section. More technical information is available at the book website, www.VaccinesExplained.com for those interested. My basic vaccination schedule and "Best Practices" for vaccinating are also included. I sincerely hope this guide aids you in making informed vaccine choices for your dog.
Vaccines for the 21st Century
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309174988
Category : Medical
Languages : en
Pages : 472
Book Description
Vaccines have made it possible to eradicate the scourge of smallpox, promise the same for polio, and have profoundly reduced the threat posed by other diseases such as whooping cough, measles, and meningitis. What is next? There are many pathogens, autoimmune diseases, and cancers that may be promising targets for vaccine research and development. This volume provides an analytic framework and quantitative model for evaluating disease conditions that can be applied by those setting priorities for vaccine development over the coming decades. The committee describes an approach for comparing potential new vaccines based on their impact on morbidity and mortality and on the costs of both health care and vaccine development. The book examines: Lessons to be learned from the polio experience. Scientific advances that set the stage for new vaccines. Factors that affect how vaccines are used in the population. Value judgments and ethical questions raised by comparison of health needs and benefits. The committee provides a way to compare different forms of illness and set vaccine priorities without assigning a monetary value to lives. Their recommendations will be important to anyone involved in science policy and public health planning: policymakers, regulators, health care providers, vaccine manufacturers, and researchers.
Publisher: National Academies Press
ISBN: 0309174988
Category : Medical
Languages : en
Pages : 472
Book Description
Vaccines have made it possible to eradicate the scourge of smallpox, promise the same for polio, and have profoundly reduced the threat posed by other diseases such as whooping cough, measles, and meningitis. What is next? There are many pathogens, autoimmune diseases, and cancers that may be promising targets for vaccine research and development. This volume provides an analytic framework and quantitative model for evaluating disease conditions that can be applied by those setting priorities for vaccine development over the coming decades. The committee describes an approach for comparing potential new vaccines based on their impact on morbidity and mortality and on the costs of both health care and vaccine development. The book examines: Lessons to be learned from the polio experience. Scientific advances that set the stage for new vaccines. Factors that affect how vaccines are used in the population. Value judgments and ethical questions raised by comparison of health needs and benefits. The committee provides a way to compare different forms of illness and set vaccine priorities without assigning a monetary value to lives. Their recommendations will be important to anyone involved in science policy and public health planning: policymakers, regulators, health care providers, vaccine manufacturers, and researchers.
Vaccines For Dummies
Author: Megan Coffee
Publisher: John Wiley & Sons
ISBN: 1119787831
Category : Health & Fitness
Languages : en
Pages : 46
Book Description
Inoculate yourself against the confusion and misinformation surrounding vaccines Measles, mumps, and rubella—oh my! Why are we vaccinating our children—and ourselves—against these diseases, and what goes on in our bodies after the needle comes out? Vaccines For Dummies will inform and entertain you about all things vax, including how the first vaccines were discovered, what’s in modern vaccines, how they are tested and approved for use, and why the CDC’s vaccine schedule is what it is. Inside, you’ll also find a complete guide to vaccine benefits, potential side effects, and contraindications, so you’ll be ready when shot time comes. From the very first inoculations hundreds of years ago to the brand new COVID-19 shot, creating immunity to diseases has become a human specialty. If you’re wondering how safe and how necessary it all is, you aren’t alone. In Vaccines For Dummies, we’ll explore the issue from every angle, empowering you to take charge of your wellbeing. With this book, you will: Discover the ABCs of vaccines, including what they’re made of and how they work Learn about each recommended childhood and adult immunization, plus the seasonal flu shot, all with this evidence-based guide Take a journey through vaccine history, meeting the major players of yesterday and today Decide what’s right for your family, with the help of the most recent vaccine science Parents, parents-to-be, adults of any age, and anyone who wants to delve into the microscopic world of pathogens and their arch nemeses (antigens and antibodies) will get a double dose of knowledge from Vaccines For Dummies.
Publisher: John Wiley & Sons
ISBN: 1119787831
Category : Health & Fitness
Languages : en
Pages : 46
Book Description
Inoculate yourself against the confusion and misinformation surrounding vaccines Measles, mumps, and rubella—oh my! Why are we vaccinating our children—and ourselves—against these diseases, and what goes on in our bodies after the needle comes out? Vaccines For Dummies will inform and entertain you about all things vax, including how the first vaccines were discovered, what’s in modern vaccines, how they are tested and approved for use, and why the CDC’s vaccine schedule is what it is. Inside, you’ll also find a complete guide to vaccine benefits, potential side effects, and contraindications, so you’ll be ready when shot time comes. From the very first inoculations hundreds of years ago to the brand new COVID-19 shot, creating immunity to diseases has become a human specialty. If you’re wondering how safe and how necessary it all is, you aren’t alone. In Vaccines For Dummies, we’ll explore the issue from every angle, empowering you to take charge of your wellbeing. With this book, you will: Discover the ABCs of vaccines, including what they’re made of and how they work Learn about each recommended childhood and adult immunization, plus the seasonal flu shot, all with this evidence-based guide Take a journey through vaccine history, meeting the major players of yesterday and today Decide what’s right for your family, with the help of the most recent vaccine science Parents, parents-to-be, adults of any age, and anyone who wants to delve into the microscopic world of pathogens and their arch nemeses (antigens and antibodies) will get a double dose of knowledge from Vaccines For Dummies.
Epidemiology and Prevention of Vaccine-Preventable Diseases, 13th Edition E-Book
Author: Jennifer Hamborsky, MPH, MCHES
Publisher: Public Health Foundation
ISBN: 0990449122
Category : Health & Fitness
Languages : en
Pages : 738
Book Description
The Public Health Foundation (PHF) in partnership with the Centers for Disease Control and Prevention (CDC) is pleased to announce the availability of Epidemiology and Prevention of Vaccine-Preventable Diseases, 13th Edition or “The Pink Book” E-Book. This resource provides the most current, comprehensive, and credible information on vaccine-preventable diseases, and contains updated content on immunization and vaccine information for public health practitioners, healthcare providers, health educators, pharmacists, nurses, and others involved in administering vaccines. “The Pink Book E-Book” allows you, your staff, and others to have quick access to features such as keyword search and chapter links. Online schedules and sources can also be accessed directly through e-readers with internet access. Current, credible, and comprehensive, “The Pink Book E-Book” contains information on each vaccine-preventable disease and delivers immunization providers with the latest information on: Principles of vaccination General recommendations on immunization Vaccine safety Child/adult immunization schedules International vaccines/Foreign language terms Vaccination data and statistics The E-Book format contains all of the information and updates that are in the print version, including: · New vaccine administration chapter · New recommendations regarding selection of storage units and temperature monitoring tools · New recommendations for vaccine transport · Updated information on available influenza vaccine products · Use of Tdap in pregnancy · Use of Tdap in persons 65 years of age or older · Use of PCV13 and PPSV23 in adults with immunocompromising conditions · New licensure information for varicella-zoster immune globulin Contact [email protected] for more information. For more news and specials on immunization and vaccines visit the Pink Book's Facebook fan page
Publisher: Public Health Foundation
ISBN: 0990449122
Category : Health & Fitness
Languages : en
Pages : 738
Book Description
The Public Health Foundation (PHF) in partnership with the Centers for Disease Control and Prevention (CDC) is pleased to announce the availability of Epidemiology and Prevention of Vaccine-Preventable Diseases, 13th Edition or “The Pink Book” E-Book. This resource provides the most current, comprehensive, and credible information on vaccine-preventable diseases, and contains updated content on immunization and vaccine information for public health practitioners, healthcare providers, health educators, pharmacists, nurses, and others involved in administering vaccines. “The Pink Book E-Book” allows you, your staff, and others to have quick access to features such as keyword search and chapter links. Online schedules and sources can also be accessed directly through e-readers with internet access. Current, credible, and comprehensive, “The Pink Book E-Book” contains information on each vaccine-preventable disease and delivers immunization providers with the latest information on: Principles of vaccination General recommendations on immunization Vaccine safety Child/adult immunization schedules International vaccines/Foreign language terms Vaccination data and statistics The E-Book format contains all of the information and updates that are in the print version, including: · New vaccine administration chapter · New recommendations regarding selection of storage units and temperature monitoring tools · New recommendations for vaccine transport · Updated information on available influenza vaccine products · Use of Tdap in pregnancy · Use of Tdap in persons 65 years of age or older · Use of PCV13 and PPSV23 in adults with immunocompromising conditions · New licensure information for varicella-zoster immune globulin Contact [email protected] for more information. For more news and specials on immunization and vaccines visit the Pink Book's Facebook fan page
Immunopotentiators in Modern Vaccines
Author: Virgil Schijns
Publisher: Elsevier
ISBN: 0080457215
Category : Medical
Languages : en
Pages : 396
Book Description
Immunopotentiators in Modern Vaccines provides an in-depth insight and overview of a number of most promising immunopotentiators in modern vaccines. In contrast to existing books on the subject it provides recent data on the critical mechanisms governing the activity of vaccine adjuvants and delivery systems. Knowledge of immunological pathways and scenarios of the cells and molecules involved is described and depicted in comprehensive illustrations. - Contributions from leading international authorities in the field - Well-illustrated, informative figures present the interactions between immunopotentiators and the host immune system - Each chapter lists advantages and potential hurdles for achieving a practical application for the specific immunopentiator
Publisher: Elsevier
ISBN: 0080457215
Category : Medical
Languages : en
Pages : 396
Book Description
Immunopotentiators in Modern Vaccines provides an in-depth insight and overview of a number of most promising immunopotentiators in modern vaccines. In contrast to existing books on the subject it provides recent data on the critical mechanisms governing the activity of vaccine adjuvants and delivery systems. Knowledge of immunological pathways and scenarios of the cells and molecules involved is described and depicted in comprehensive illustrations. - Contributions from leading international authorities in the field - Well-illustrated, informative figures present the interactions between immunopotentiators and the host immune system - Each chapter lists advantages and potential hurdles for achieving a practical application for the specific immunopentiator
Stuck
Author: Heidi J. Larson
Publisher: Oxford University Press
ISBN: 0190077255
Category : Medical
Languages : en
Pages : 224
Book Description
Vaccine reluctance and refusal are no longer limited to the margins of society. Debates around vaccines' necessity -- along with quesitons around their side effects -- have gone mainstream, blending with geopolitical conflicts, political campaigns, celebrity causes, and "natural" lifestyles to win a growing number of hearts and minds. Today's anti-vaccine positions find audiences where they've never existed previously. Stuck examines how the issues surrounding vaccine hesitancy are, more than anything, about people feeling left out of the conversation. A new dialogue is long overdue, one that addresses the many types of vaccine hesitancy and the social factors that perpetuate them. To do this, Stuck provides a clear-eyed examination of the social vectors that transmit vaccine rumors, their manifestations around the globe, and how these individual threads are all connected.
Publisher: Oxford University Press
ISBN: 0190077255
Category : Medical
Languages : en
Pages : 224
Book Description
Vaccine reluctance and refusal are no longer limited to the margins of society. Debates around vaccines' necessity -- along with quesitons around their side effects -- have gone mainstream, blending with geopolitical conflicts, political campaigns, celebrity causes, and "natural" lifestyles to win a growing number of hearts and minds. Today's anti-vaccine positions find audiences where they've never existed previously. Stuck examines how the issues surrounding vaccine hesitancy are, more than anything, about people feeling left out of the conversation. A new dialogue is long overdue, one that addresses the many types of vaccine hesitancy and the social factors that perpetuate them. To do this, Stuck provides a clear-eyed examination of the social vectors that transmit vaccine rumors, their manifestations around the globe, and how these individual threads are all connected.
Adverse Effects of Vaccines
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309214351
Category : Medical
Languages : en
Pages : 894
Book Description
In 1900, for every 1,000 babies born in the United States, 100 would die before their first birthday, often due to infectious diseases. Today, vaccines exist for many viral and bacterial diseases. The National Childhood Vaccine Injury Act, passed in 1986, was intended to bolster vaccine research and development through the federal coordination of vaccine initiatives and to provide relief to vaccine manufacturers facing financial burdens. The legislation also intended to address concerns about the safety of vaccines by instituting a compensation program, setting up a passive surveillance system for vaccine adverse events, and by providing information to consumers. A key component of the legislation required the U.S. Department of Health and Human Services to collaborate with the Institute of Medicine to assess concerns about the safety of vaccines and potential adverse events, especially in children. Adverse Effects of Vaccines reviews the epidemiological, clinical, and biological evidence regarding adverse health events associated with specific vaccines covered by the National Vaccine Injury Compensation Program (VICP), including the varicella zoster vaccine, influenza vaccines, the hepatitis B vaccine, and the human papillomavirus vaccine, among others. For each possible adverse event, the report reviews peer-reviewed primary studies, summarizes their findings, and evaluates the epidemiological, clinical, and biological evidence. It finds that while no vaccine is 100 percent safe, very few adverse events are shown to be caused by vaccines. In addition, the evidence shows that vaccines do not cause several conditions. For example, the MMR vaccine is not associated with autism or childhood diabetes. Also, the DTaP vaccine is not associated with diabetes and the influenza vaccine given as a shot does not exacerbate asthma. Adverse Effects of Vaccines will be of special interest to the National Vaccine Program Office, the VICP, the Centers for Disease Control and Prevention, vaccine safety researchers and manufacturers, parents, caregivers, and health professionals in the private and public sectors.
Publisher: National Academies Press
ISBN: 0309214351
Category : Medical
Languages : en
Pages : 894
Book Description
In 1900, for every 1,000 babies born in the United States, 100 would die before their first birthday, often due to infectious diseases. Today, vaccines exist for many viral and bacterial diseases. The National Childhood Vaccine Injury Act, passed in 1986, was intended to bolster vaccine research and development through the federal coordination of vaccine initiatives and to provide relief to vaccine manufacturers facing financial burdens. The legislation also intended to address concerns about the safety of vaccines by instituting a compensation program, setting up a passive surveillance system for vaccine adverse events, and by providing information to consumers. A key component of the legislation required the U.S. Department of Health and Human Services to collaborate with the Institute of Medicine to assess concerns about the safety of vaccines and potential adverse events, especially in children. Adverse Effects of Vaccines reviews the epidemiological, clinical, and biological evidence regarding adverse health events associated with specific vaccines covered by the National Vaccine Injury Compensation Program (VICP), including the varicella zoster vaccine, influenza vaccines, the hepatitis B vaccine, and the human papillomavirus vaccine, among others. For each possible adverse event, the report reviews peer-reviewed primary studies, summarizes their findings, and evaluates the epidemiological, clinical, and biological evidence. It finds that while no vaccine is 100 percent safe, very few adverse events are shown to be caused by vaccines. In addition, the evidence shows that vaccines do not cause several conditions. For example, the MMR vaccine is not associated with autism or childhood diabetes. Also, the DTaP vaccine is not associated with diabetes and the influenza vaccine given as a shot does not exacerbate asthma. Adverse Effects of Vaccines will be of special interest to the National Vaccine Program Office, the VICP, the Centers for Disease Control and Prevention, vaccine safety researchers and manufacturers, parents, caregivers, and health professionals in the private and public sectors.
Immunization in Practice
Author:
Publisher: World Health Organization
ISBN: 9241549092
Category : Medical
Languages : en
Pages : 292
Book Description
This practical guide contains seven modules targeted at district and health facility staff. It intends to meet the demands to improve immunization services so as to reach more infants in a sustainable way, building upon the experiences of polio eradication. It includes materials adapted from polio on planning, monitoring and use of data to improve the service, that can be used at any level. Revising the manual has been a team exercise. There are contributions from a large number of experts, organizations and institutions. This new edition has seven modules. Several new vaccines that have become more readily available and used in recent years have been added. Also the section on integration with other health interventions has been expanded as exciting opportunities and experiences have become evident in the years following the previous edition. Module 1: Target diseases and vaccines Module 2: The vaccine cold chain Module 3: Ensuring safe injections Module 4: Microplanning for reaching every community Module 5: Managing an immunization session Module 6: Monitoring and surveillance Module 7: Partnering with communities.
Publisher: World Health Organization
ISBN: 9241549092
Category : Medical
Languages : en
Pages : 292
Book Description
This practical guide contains seven modules targeted at district and health facility staff. It intends to meet the demands to improve immunization services so as to reach more infants in a sustainable way, building upon the experiences of polio eradication. It includes materials adapted from polio on planning, monitoring and use of data to improve the service, that can be used at any level. Revising the manual has been a team exercise. There are contributions from a large number of experts, organizations and institutions. This new edition has seven modules. Several new vaccines that have become more readily available and used in recent years have been added. Also the section on integration with other health interventions has been expanded as exciting opportunities and experiences have become evident in the years following the previous edition. Module 1: Target diseases and vaccines Module 2: The vaccine cold chain Module 3: Ensuring safe injections Module 4: Microplanning for reaching every community Module 5: Managing an immunization session Module 6: Monitoring and surveillance Module 7: Partnering with communities.
Vaccine Safety Forum
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309057914
Category : Medical
Languages : en
Pages : 71
Book Description
On November 6, 1995, the Institute of Medicine's Vaccine Safety Forum convened a workshop on detecting and responding to adverse events following vaccination. Workshop speakers and participants discussed the difficulties in detecting adverse events, current adverse events detection and response methods and procedures, suggestions for improving the means of detecting and responding to adverse events following vaccination, and future areas of research. This document represents a summary of that workshop.
Publisher: National Academies Press
ISBN: 0309057914
Category : Medical
Languages : en
Pages : 71
Book Description
On November 6, 1995, the Institute of Medicine's Vaccine Safety Forum convened a workshop on detecting and responding to adverse events following vaccination. Workshop speakers and participants discussed the difficulties in detecting adverse events, current adverse events detection and response methods and procedures, suggestions for improving the means of detecting and responding to adverse events following vaccination, and future areas of research. This document represents a summary of that workshop.