Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating the body's adaptive immunity, they help prevent sickness from an infectious disease. When a sufficiently large percentage of a population has been vaccinated, herd immunity results. Herd immunity protects those who may be immunocompromised and cannot get a vaccine because even a weakened version would harm them. The effectiveness of vaccination has been widely studied and verified. Vaccination is the most effective method of preventing infectious diseases; widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the elimination of diseases such as polio and tetanus from much of the world. However, some diseases, such as measles outbreaks in America, have seen rising cases due to relatively low vaccination rates in the 2010s – attributed, in part, to vaccine hesitancy.
The MMR vaccine is a vaccine against measles, mumps, and rubella. The first dose is generally given to children around 9 months to 15 months of age, with a second dose at 15 months to 6 years of age, with at least 4 weeks between the doses. After two doses, 97% of people are protected against measles, 88% against mumps, and at least 97% against rubella. The vaccine is also recommended for those who do not have evidence of immunity, those with well-controlled HIV/AIDS, and within 72 hours of exposure to measles among those who are incompletely immunized. It is given by injection.
The DPT vaccine or DTP vaccine is a class of combination vaccines against three infectious diseases in humans: diphtheria, pertussis, and tetanus. The vaccine components include diphtheria and tetanus toxoids and either killed whole cells of the bacterium that causes pertussis or pertussis antigens. The whole cells or antigens will be depicted as either "DTwP" or "DTaP", where the lower-case "w" indicates whole-cell inactivated pertussis and the lower-case "a" stands for “acellular”.
Influenza vaccines, also known as flu jabs or flu shots, are vaccines that protect against infection by influenza viruses. New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. The United States Centers for Disease Control and Prevention (CDC) estimates that vaccination against influenza reduces sickness, medical visits, hospitalizations, and deaths. Immunized workers who do catch the flu return to work half a day sooner on average. Vaccine effectiveness in those over 65 years old remains uncertain due to a lack of high-quality research. Vaccinating children may protect those around them.
Human papillomavirus (HPV) vaccines are vaccines that prevent infection by certain types of human papillomavirus (HPV). Available HPV vaccines protect against either two, four, or nine types of HPV. All HPV vaccines protect against at least HPV types 16 and 18, which cause the greatest risk of cervical cancer. It is estimated that HPV vaccines may prevent 70% of cervical cancer, 80% of anal cancer, 60% of vaginal cancer, 40% of vulvar cancer, and show more than 90% efficacy in preventing HPV-positive oropharyngeal cancers. They additionally prevent some genital warts, with the quadrivalent and nonavalent vaccines that protect against HPV types HPV-6 and HPV-11 providing greater protection.
The Advisory Committee on Immunization Practices (ACIP), is a committee within the United States Centers for Disease Control and Prevention (CDC) that provides advice and guidance on effective control of vaccine-preventable diseases in the U.S. civilian population. The ACIP develops written recommendations for routine administration of vaccines to the pediatric and adult populations, along with vaccination schedules regarding appropriate timing, dosage, and contraindications of vaccines. ACIP statements are official federal recommendations for the use of vaccines and immune globulins in the U.S., and are published by the CDC.
Neal A. Halsey is an American pediatrician, with sub-specialty training in infectious diseases, international health and epidemiology. Halsey is a professor emeritus of international health and director emeritus of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health, in Baltimore, Maryland. He had a joint appointment in the Department of Pediatrics at the Johns Hopkins School of Medicine and serves as co-director of the Center for Disease Studies and Control in Guatemala.
The MMRV vaccine combines the attenuated virus MMR vaccine with the addition of the chickenpox vaccine or varicella vaccine. The MMRV vaccine is typically given to children between one and two years of age.
The National Center for Immunization and Respiratory Diseases (NCIRD), formerly known as the National Immunization Program until April 2006, is charged with responsibility for the planning, coordination, and conduct of immunization activities in the United States. NCIRD is a part of the Centers for Disease Control and Prevention, located in Atlanta, Georgia, and housed in the CDC's Coordinating Center for Infectious Diseases (CCID). The National Center for Immunization provides consultation, training, statistical, promotional, educational, epidemiological, and technical services to assist state and local health departments across the US in planning, developing, contracting and implementing immunization programs.
A zoster vaccine is a vaccine that reduces the incidence of herpes zoster (shingles), a disease caused by reactivation of the varicella zoster virus (VZV), which is also responsible for chickenpox. Shingles provokes a painful rash with blisters, and can be followed by chronic pain, as well as other complications. Older people are more often affected, as are people with weakened immune systems (immunosuppression). Both shingles and postherpetic neuralgia can be prevented by vaccination.
NmVac4-A/C/Y/W-135 is the commercial name of the polysaccharide vaccine against the bacterium that causes meningococcal meningitis. The product, by JN-International Medical Corporation, is designed and formulated to be used in developing countries for protecting populations during meningitis disease epidemics.
Meningococcal vaccine refers to any vaccine used to prevent infection by Neisseria meningitidis. Different versions are effective against some or all of the following types of meningococcus: A, B, C, W-135, and Y. The vaccines are between 85 and 100% effective for at least two years. They result in a decrease in meningitis and sepsis among populations where they are widely used. They are given either by injection into a muscle or just under the skin.
Measles vaccine protects against becoming infected with measles. Nearly all of those who do not develop immunity after a single dose develop it after a second dose. When rates of vaccination within a population are greater than 92%, outbreaks of measles typically no longer occur; however, they may occur again if rates of vaccination decrease. The vaccine's effectiveness lasts many years. It is unclear if it becomes less effective over time. The vaccine may also protect against measles if given within a couple of days after exposure to measles.
Yellow fever vaccine is a vaccine that protects against yellow fever. Yellow fever is a viral infection that occurs in Africa and South America. Most people begin to develop immunity within ten days of vaccination and 99 percent are protected within one month, and this appears to be lifelong. The vaccine can be used to control outbreaks of disease. It is given either by injection into a muscle or just under the skin.
The Vaccines for Children Program (VFC) is a federally funded program in the United States providing no-cost vaccines to children who lack health insurance or who otherwise cannot afford the cost of the vaccination. The VFC program was created by the Omnibus Budget Reconciliation Act of 1993 and is required to be a new entitlement of each state's Medicaid plan under section 1928 of the Social Security Act. The program was officially implemented in October 1994 and serves eligible children in all U.S. states, as well as the Commonwealth of Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands.
A Vaccine Information Statement (VIS) is a document designed by the Centers for Disease Control and Prevention (CDC) to provide information to a patient receiving a vaccine in the United States. The National Childhood Vaccine Injury Act requires that medical professionals provide a VIS to patients before receiving certain vaccinations. The VIS includes information about the vaccine's benefits and risks, a description of the vaccine, indications and contraindications, instructions for patients experiencing an adverse reaction, and additional resources.
Tetanus vaccine, also known as tetanus toxoid (TT), is a toxoid vaccine used to prevent tetanus. During childhood, five doses are recommended, with a sixth given during adolescence.
National Immunization Technical Advisory Group (NITAG) is an advisory committee consisting of multidisciplinary groups of experts responsible for providing information to national governments that is used to make evidence-based decisions regarding vaccine and immunization policy. The majority of industrialized and some developing countries have formally established advisory committees to guide immunization policies; other countries are working towards establishment of such committees. NITAG in each country may have different names, for example: Advisory Committee on Immunization Practices (ACIP) in the United States, Australian Technical Advisory Group on Immunisation (ATAGI) in Australia, Joint Committee on Vaccination and Immunisation (JCVI) in the United Kingdom, National Advisory Committee on Immunization (NACI) in Canada, National Immunisation Advisory Committee (NIAC) in Ireland, National Technical Advisory Group on Immunisation (NTAGI) in India, Standing Committee on Vaccination in Germany, and Technical Committee of Vaccination in France.
Helen Petousis-Harris is a New Zealand vaccinologist and associate professor in the Department of General Practice and Primary Health Care at the University of Auckland. She has been involved in research related to vaccination in New Zealand since 1998, with her main areas of focus being vaccine safety and effectiveness. Petousis-Harris has had a variety of lead roles in New Zealand and international organisations that focus on vaccination and is a regular media spokesperson in this field, especially during the COVID-19 pandemic.
Dr. Shelley Deeks, MD, MHSc, FRCPC, FFAFPM, is a Canadian public health expert who is the Chair of the National Advisory Committee on Immunization. Her advertised "specialities include communicable disease control, outbreak investigations, vaccine safety, epidemiology and program evaluation." She is a fellow of the Royal College of Physicians of Canada and the Australian Faculty of Public Health Medicine. Deeks was the executive lead in Ontario's COVID-19 pandemic response in 2020 in her role at Public Health Ontario.
