Vaccine description | |
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Target | Hepatitis A virus |
Vaccine type | Inactivated or attenuated |
Clinical data | |
Trade names | Havrix, others |
AHFS/Drugs.com | Monograph |
MedlinePlus | a695003 |
Pregnancy category |
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Routes of administration | Intramuscular |
ATC code | |
Legal status | |
Legal status | |
Identifiers | |
DrugBank | |
ChemSpider |
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UNII | |
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Hepatitis A vaccine is a vaccine that prevents hepatitis A. [2] [3] It is effective in around 95% of cases and lasts for at least twenty years and possibly a person's entire life. [4] If given, two doses are recommended beginning after the age of one. [2] It is given by injection into a muscle. [2] The first hepatitis A vaccine was approved in the European Union in 1991, and the United States in 1995. [5] It is on the World Health Organization's List of Essential Medicines. [6]
The World Health Organization (WHO) recommends universal vaccination in areas where the disease is moderately common. [2] Where the disease is very common, widespread vaccination is not recommended as all people typically develop immunity through infection during childhood. [2] The US Centers for Disease Control and Prevention (CDC) recommends vaccinating: [7]
In addition, a person who has not previously received hepatitis A vaccine and who has direct contact with someone with hepatitis A should get hepatitis A vaccine within two weeks after exposure. [8]
Severe side effects are very rare. [2] Pain at the site of injection occurs in about 15% of children and half of adults. [2] Most hepatitis A vaccines contain inactivated virus while a few contain weakened virus. [2] The ones with weakened virus are not recommended during pregnancy or in those with poor immune function. [2] A few formulations combine hepatitis A with either hepatitis B or typhoid vaccine. [2]
Soreness or redness where the shot is given, fever, headache, tiredness, or loss of appetite can happen after hepatitis A vaccine. As with any medicine, there is a very remote chance of a vaccine causing a severe allergic reaction, other serious injury, or death. [8]
Within the US, the vaccine Vaqta, developed by Maurice Hilleman and his team at Merck & Co. was licensed in 1995. [9] [10] [11] The vaccine was phased in, around 1996, for children living in high-risk areas. In 1999, its usage was widened to areas with elevating levels of infection. In the US as of 2007 [update] , the vaccine is strongly recommended for all children 12 to 23 months of age in an attempt to eradicate the virus nationwide. Although the original Food and Drug Administration (FDA) license for Havrix by GlaxoSmithKline is dated 1995, [12] it had been approved in Europe in 1991. [5] [13]
The US Centers for Disease Control and Prevention (CDC) recommends vaccination of all children over one year of age, people whose sexual activity puts them at risk, people with chronic liver disease, people who are being treated with clotting factor concentrates, people working in close proximity to the virus, and people who are living in communities where an outbreak is present. [14] Hepatitis A is the most common vaccine-preventable virus acquired during travel, [15] so people traveling to places where the virus is common like the Indian subcontinent, Africa, Central America, South America, Asia, and Eastern Europe should be vaccinated. [14] [16]
The vaccine is given in the muscle of the upper arm, in two doses for the best protection. The initial dose of the vaccine should be followed up by a booster six to twelve months later. [14] Protection against hepatitis A begins approximately two to four weeks after the initial vaccination. [14] [16] Protection lasts at least 15 years and is estimated to last at least 25 years if the booster is administered. [17]
A Cochrane review found that both types of vaccines offer significant protection, for at least two years using the inactivated vaccine and at least five years with the attenuated vaccine. The review concluded that the inactivated vaccine is safe, but required more high quality evidence to assess the safety of the attenuated vaccine. [18] [ needs update ]
Several commercial hepatitis A vaccines are available. The definition of (U)nits varies among manufacturers depending on how hepatitis A antigen is measured in their products.
The MMR vaccine is a vaccine against measles, mumps, and rubella, abbreviated as MMR. 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 four 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 to protect against three infectious diseases in humans: diphtheria, pertussis, and tetanus (lockjaw). The vaccine components include diphtheria and tetanus toxoids, and either killed whole cells of the bacterium that causes pertussis or pertussis antigens. The term toxoid refers to vaccines which use an inactivated toxin produced by the pathogen which they are targeted against to generate an immune response. In this way, the toxoid vaccine generates an immune response which is targeted against the toxin which is produced by the pathogen and causes disease, rather than a vaccine which is targeted against the pathogen itself. 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". In comparison to alternative vaccine types, such as live attenuated vaccines, the DTP vaccine does not contain any live pathogen, but rather uses inactivated toxoid to generate an immune response; therefore, there is not a risk of use in populations that are immune compromised since there is not any known risk of causing the disease itself. As a result, the DTP vaccine is considered a safe vaccine to use in anyone and it generates a much more targeted immune response specific for the pathogen of interest.
Influenza vaccines, colloquially known as flu shots or the flu jab, 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. Vaccination against influenza began in the 1930s, with large-scale availability in the United States beginning in 1945.
Mumps vaccines are vaccines which prevent mumps. When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful.
Combined hepatitis A and B vaccine, is used to provide protection against hepatitis A and hepatitis B. It is given by injection into muscle.
A zoster vaccine is a vaccine that reduces the incidence of herpes zoster (shingles), a disease caused by reactivation of the varicella zoster virus, 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.
Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox. One dose of vaccine prevents 95% of moderate disease and 100% of severe disease. Two doses of vaccine are more effective than one. If given to those who are not immune within five days of exposure to chickenpox it prevents most cases of disease. Vaccinating a large portion of the population also protects those who are not vaccinated. It is given by injection just under the skin. Another vaccine, known as zoster vaccine, is used to prevent diseases caused by the same virus – the varicella zoster virus.
Hepatitis B vaccine is a vaccine that prevents hepatitis B. The first dose is recommended within 24 hours of birth with either two or three more doses given after that. This includes those with poor immune function such as from HIV/AIDS and those born premature. It is also recommended that health-care workers be vaccinated. In healthy people, routine immunization results in more than 95% of people being protected.
The Haemophilus influenzae type B vaccine, also known as Hib vaccine, is a vaccine used to prevent Haemophilus influenzae type b (Hib) infection. In countries that include it as a routine vaccine, rates of severe Hib infections have decreased more than 90%. It has therefore resulted in a decrease in the rate of meningitis, pneumonia, and epiglottitis.
The rabies vaccine is a vaccine used to prevent rabies. There are several rabies vaccines available that are both safe and effective. Vaccinations must be administered prior to rabies virus exposure or within the latent period after exposure to prevent the disease. Transmission of rabies virus to humans typically occurs through a bite or scratch from an infectious animal, but exposure can occur through indirect contact with the saliva from an infectious individual.
Diphtheria vaccine is a toxoid vaccine against diphtheria, an illness caused by Corynebacterium diphtheriae. Its use has resulted in a more than 90% decrease in number of cases globally between 1980 and 2000. The first dose is recommended at six weeks of age with two additional doses four weeks apart, after which it is about 95% effective during childhood. Three further doses are recommended during childhood. It is unclear if further doses later in life are needed.
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.
Tick-borne encephalitis vaccine is a vaccine used to prevent tick-borne encephalitis (TBE). The disease is most common in Central and Eastern Europe, and Northern Asia. More than 87% of people who receive the vaccine develop immunity. It is not useful following the bite of an infected tick. It is given by injection into a muscle.
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 the rate of vaccination within a population is greater than 92%, outbreaks of measles typically no longer occur; however, they may occur again if the rate of vaccination decreases. 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% 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.
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.
DTaP-IPV-HepB vaccine is a combination vaccine whose generic name is diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B (recombinant) and inactivated polio vaccine or DTaP-IPV-Hep B. It protects against the infectious diseases diphtheria, tetanus, pertussis, poliomyelitis, and hepatitis B.
Hepatitis A and typhoid vaccine is a combination vaccine to protect against the infectious diseases hepatitis A and typhoid. It is a combination of inactivated Hepatitis A virus and Vi polysaccharide of Salmonella typhi bacteria. Branded formulations include Hepatyrix from GlaxoSmithKline, and ViVaxim and ViATIM from Sanofi Pasteur.
Type A influenza vaccine is for the prevention of infection of influenza A virus and also the influenza-related complications. Different monovalent type A influenza vaccines have been developed for different subtypes of influenza A virus including H1N1 and H5N1. Both intramuscular injection or intranasal spray are available on market. Unlike the seasonal influenza vaccines which are used annually, they are usually used during the outbreak of certain strand of subtypes of influenza A. Common adverse effects includes injection site reaction and local tenderness. Incidences of headache and myalgia were also reported with H1N1 whereas cases of fever has also been demonstrated with H5N1 vaccines. It is stated that immunosuppressant therapies would reduce the therapeutic effects of vaccines and that people with egg allergy should go for the egg-free preparations.