What happens if you get hep a vaccine twice

In addition, previously homeless persons who are to be released from a prison or a hospital might be considered homeless if they do not have a stable housing situation to which they can return. The instability of a person's living arrangements is critical to the definition of homelessness.

Some people on my team are worried about initiating the HepA vaccine series in people who are homeless because we may not be able to complete the series or keep up with their records over time. How much of a concern is this? While a complete series of HepA is recommended for long-term protection, even a single dose of HepA vaccine has been demonstrated to provide protection against hepatitis A for more than 10 years and can prevent or control outbreaks of hepatitis A.

People who are experiencing homelessness may have difficulty protecting themselves from exposure to HAV in other ways because of their living conditions. They should be vaccinated when possible and provided a record of immunization. Reporting the HepA vaccination to a state immunization information system also can facilitate immunization assessment at future healthcare encounters. Should healthcare providers HCP be vaccinated routinely against hepatitis A?

A number of studies have shown that HCP are not at significantly increased risk of HAV infection because of their occupation. However, if HCPs are going to work or vacation in a country with a high or intermediate endemic rate of HAV infection, they are at risk of HAV infection and should be vaccinated. The only occupational indications for routine HepA vaccination are work with non-human primates or live HAV in a laboratory setting. Should daycare workers be routinely vaccinated against hepatitis A?

In the past, outbreaks of hepatitis A occurred among children in child care centers, infecting employees of those centers, especially those caring for infants and toddlers. Following widespread adoption of early childhood vaccination against hepatitis A, outbreaks in child care centers are now rare.

Why is hepatitis A vaccination recommended for people with chronic liver disease? Although not at increased risk for HAV infection, people with chronic liver disease are at increased risk for fulminant hepatitis A, hospitalization and death if they become infected with HAV. For this reason, hepatitis A vaccination is recommended for them. Why isn't hepatitis A vaccination recommended for sewage and solid waste disposal workers?

In published reports of three serologic surveys conducted among United States wastewater workers and appropriate comparison populations, no substantial or consistent increase in the prevalence of anti-HAV was identified among wastewater workers. No work-related instances of HAV transmission have been reported among wastewater workers in the United States.

In addition, in the United States, outbreaks of hepatitis A caused by flooding, which can carry raw sewage, have not been reported.

Why is hepatitis A vaccination no longer recommended for people with clotting factor disorders? Why is hepatitis A vaccination recommended and IG not recommended for infant travelers age 6 through 11 months at risk of exposure to HAV? Because of measles. Measles is highly communicable and poses a serious threat to the health of unvaccinated infants.

For this reason, all infants age 6 through 11 months who travel internationally are recommended to receive a dose of measles, mumps, and rubella vaccine MMR to reduce the risk of measles infection during travel. The antibodies in immune globulin IG typically used to prevent HAV infection in infants before the first birthday can interfere with the effectiveness of MMR vaccine.

The HepA and MMR doses administered before the first birthday do not count toward the routine vaccination series of either vaccine: these infant travelers will still need two doses of HepA and two doses of MMR when age appropriate.

Can pregnant women receive hepatitis A vaccine? The ACIP recommends that pregnant women at risk for HAV infection during pregnancy or at risk for a severe outcome from HAV infection should be vaccinated during pregnancy if not previously vaccinated.

Pregnant women should be vaccinated for the same indications as non-pregnant women. For additional information, see page 20 of the recommendations: www. Administering Vaccines Back to top By what method should hepatitis A vaccine be administered?

Hepatitis A vaccine HepA should be administered intramuscularly IM , using the appropriate injection site and needle size as determined by the patient's age and body mass. Can HepA vaccine be given concurrently with other vaccines? If given in the same muscle, separate the injections by a minimum distance of 1 inch.

What happens if dose 2 of HepA vaccine is delayed? You do not need to start the series over again. To ensure optimal long-term protection it is important to administer the second dose. To complete a year-old patient's HepA vaccine series, how many adult doses should I give if the patient received a single dose of pediatric HepA vaccine 5 years ago? A person should receive the dosage of HepA vaccine appropriate for their age at the time of administration.

You should give the patient one adult dose of HepA to complete the 2-dose series. It is not necessary to restart the vaccine series. One of our staff gave a dose of pediatric HepA vaccine to an adult patient by mistake. How do we remedy this error? In general, if the error is discovered on the same clinic day, you can administer the other "half" of the dose on that same day. If the error is discovered later, the dose should not be counted, and then the person should be recalled to the office and given a full age-appropriate repeat dose.

There may be an increased risk of a local adverse reaction when more than the recommended dose is given. If the error occurred with the first dose of the series the child should still receive the second dose on schedule. Giving a "double" dose for the first dose does not negate the need for a second dose. Avoid such errors by checking the vaccine vial label 3 times. Why does a year old who weighs pounds receive a pediatric dose of HepA while his pound mother receives an adult dose twice the pediatric dose?

The efficacy data from the clinical trials were based on age at time of vaccination, and not on the weight of the individual. Hence, the dosage recommendations reflect this age-based efficacy data.

The same holds true for HepB vaccine. In addition, higher response rates are expected in younger people, even if their weights are above the norm. Twinrix Back to top Could you please provide more information about Twinrix the combination hepatitis A and B vaccine and the two schedules for its use?

The vaccine contains EL. In the U. It can be administered to people who are at risk for both hepatitis A and hepatitis B, such as certain international travelers, people with HIV infection, people with chronic liver disease not caused by hepatitis B, men who have sex with men, illegal drug users, or to people who simply want to be immune to both diseases. Primary immunization consists of 3 doses given intramuscularly on a 0, 1, and 6 month schedule. In , the FDA also approved a 4-dose schedule for Twinrix.

The 4-dose schedule could benefit individuals needing rapid protection from hepatitis A and hepatitis B, such as people traveling to high-prevalence areas imminently. Twinrix cannot be used for postexposure prophylaxis. I have seen adults who have had 1 or 2 doses of Twinrix, but we only carry single-antigen vaccine in our practice. How should we complete their vaccination series with single-antigen vaccines?

Twinrix is licensed as a 3-dose series for people age 18 years and older. If Twinrix is not available or if you choose not to use Twinrix to complete the Twinrix series, you should do the following: If 1 dose of Twinrix was given, complete the series with 2 adult doses of hepatitis B vaccine and 2 adult doses of hepatitis A vaccine. If 2 doses of Twinrix were given, complete the schedule with 1 adult dose of hepatitis A vaccine and 1 adult dose of hepatitis B vaccine.

Another way to consider this is as follows: A dose of Twinrix contains a standard adult dose of hepatitis B vaccine and a pediatric dose of hepatitis A vaccine. Thus, a dose of Twinrix can be substituted for any dose of the hepatitis B series but not for any dose of the hepatitis A series.

We're thinking of using Twinrix and we're wondering whether we can use it for doses 1 and 3 only and use single antigen hepatitis B vaccine for dose 2? For this reason, 3 doses of Twinrix must comprise the series. In addition, the Food and Drug Administration requires that the process used to produce IG include a viral inactivation step or that final products test negative for HCV-RNA by polymerase chain reaction.

Anti-HAV concentrations differ among IG lots, and decreasing concentrations have been observed over the past 30 years, probably because of the decreasing prevalence of previous HAV infection among plasma donors. How does immune globulin IG work?

IG provides protection against HAV infection through passive transfer of antibody. Depending on the IG dosage, protection lasts from 1 to 2 months. When administered for preexposure prophylaxis, a dose of 0. If longer term protection is required and vaccination is contraindicated, a dose of 0.

For postexposure prophylaxis, the recommended dosage is 0. There is no maximum dosage of IG for hepatitis A prophylaxis.

How is IG packaged and how is IG administered? Intramuscular IG is available in single-use vials 2 mL and 10 mL. It should be administered intramuscularly, preferably in the anterolateral aspects of the upper thigh and the deltoid muscle of the upper arm. Do not use the gluteal region as an injection site because of the risk of injury to the sciatic nerve. Does IG cause adverse events? Anaphylaxis has been reported after repeated administration to people with known immunoglobulin A IgA deficiency; thus, IG should not be administered to these people.

IG products including GamaSTAN have been associated with the formation of blood clots thrombosis after administration, particularly if the patient has other risk factors for thrombosis.

Patients should be counseled about this risk. Can pregnant or lactating women receive IG? Pregnancy or lactation is not a contraindication to IG administration if clearly needed. She's scheduled for her month-old well-child visit. Will this affect her vaccination schedule?

IG may be given any time before or after inactivated vaccines. However, the antibodies in IG may interfere with the effectiveness of certain live-virus vaccines, such as measles, mumps, and rubella MMR and varicella vaccines.

Please see details of the recommendations for the use of IG for the prevention of hepatitis A provided in Table 4 page 19 and Appendices A and B of the ACIP recommendations for the prevention of hepatitis A infection: www. Hepatitis A vaccination is recommended for people age 6 months or older who are traveling to or working in an area of the world at intermediate or high risk of hepatitis A transmission. What are the recommendations for vaccination of travelers to protect them from hepatitis A virus HAV infection?

For details on preexposure protection of international travelers age 12 months and older, refer to Appendix A on page 35 of the current ACIP recommendations for the prevention of hepatitis A: www.

Healthy people age 12 months through 40 years who are planning travel to an area with high or intermediate HAV endemicity and have not received HepA vaccine should receive a single dose of HepA vaccine as soon as travel is considered and should complete the 2-does series according to the routine schedule.

People with chronic liver disease as well as adults older than 40 years of age, immunocompromised persons, and persons with other chronic medical conditions planning to depart to an area with high or intermediate HAV endemicity in less than 2 weeks should receive the initial dose of HepA vaccine, and may also simultaneously be administered IG at a separate anatomic injection site for example in separate limbs. ACIP revised its recommendations for preexposure hepatitis A vaccination for travelers in to include vaccination of infants 6 through 11 months of age.

All infants of this age traveling internationally should be given a dose of measles, mumps, rubella vaccine MMR before travel. The routine 2-dose HepA and MMR vaccination series should be initiated at age 12 months according to the routine, age-appropriate vaccination schedule. Infants younger than 6 months and travelers who elect not to receive vaccine or for whom vaccine is contraindicated should receive a single 0.

If travel is for more than 1 month, a dose of 0. Can Twinrix be used for people planning international travel? If time allows, use the standard Twinrix schedule of 3 doses given intramuscularly on a 0, 1, and 6 month schedule. If travel is imminent the accelerated 4-dose Twinrix schedule can be used, which is 3 doses given on days 0, 7, and days and a booster dose at 12 months. We have an adult patient who received the correct pediatric series of HepA vaccine as a teenager and is now traveling abroad.

Does the patient need an adult booster? There is no recommendation for a booster dose of HepA if a patient has completed the 2-dose series at any age. Is it really necessary to vaccinate travelers to Latin America who will be staying in 4-star hotels? Data have shown that people acquire HAV infection even in such places as 4-star hotels located in Latin America. If a traveler received the first dose of HepA vaccine more than one year ago and needs to travel abroad imminently, will the traveler need IG in addition to dose 2 prior to leaving?

Just give the final dose of HepA vaccine prior to travel. Since IG protects against HAV infection for only 1 to 2 months, depending on the dosage given, additional IG may be needed if the infant is not yet age 6 months.

Once the child has reached six months of age, HepA vaccine should be given. ACIP recommends that all children age 1 year through 18 years should be vaccinated against hepatitis A.

VFC HepA vaccine may be administered to any eligible child, including those recommended for vaccination at 6 through 11 months of age as a result of travel to an HAV-endemic area. If a person was born and grew up in a country where HAV infection is endemic e. It depends on whether that person has a history of HAV infection. Unless there are medical records that document prior HAV infection, serologic testing for immunity positive test for total anti-HAV is the only way to determine if vaccination is necessary.

For people from countries with high rates of HAV infection, such as Vietnam and Mexico, serologic testing might be done to prevent unnecessary vaccination. The cost effectiveness of serologic testing, however, should be balanced against the possibility of delaying needed vaccination while awaiting test results.

If a person has had HAV infection, should they still receive the vaccine if planning international travel? No, as long as there are medical records that document that the person was previously infected with HAV i. The vaccine or IG will not harm a person who is already immune. No serious adverse events have been attributed definitively to HepA vaccine. Among adults, the most frequently reported side effects are soreness at the site of the injection and headache.

In children, the most frequently reported side effect is soreness at the injection site. The frequency of side effects after administration of Twinrix is similar to those reported when the two single-antigen vaccines were administered. Contraindications and Precautions Back to top What contraindications and precautions should be followed when administering HepA vaccine?

Hepatitis A vaccine is contraindicated for people with a history of a severe allergic reaction to a previous dose of HepA vaccine or to a vaccine component. As with all other vaccines, there is a precaution when giving it to anyone who is moderately or severely ill. Can pregnant women receive HepA vaccine? ACIP recommends that pregnant women at risk for HAV infection during pregnancy or at risk for a severe outcome from HAV infection should be vaccinated during pregnancy if not previously vaccinated.

For additional details, see page 20 of the current ACIP recommendations: www. Can lactating women receive HepA vaccine? HepA vaccine is an inactivated vaccine and poses no harm to the nursing infant. Can HepA vaccine be given to immunocompromised people? If any immunocompromised person has a risk factor that places them at increased risk of hepatitis A e. I have a patient on interferon for hepatitis C, but I want to give him HepA vaccine. Is it okay to vaccinate him against hepatitis A while he is on interferon?

HepA vaccine should be given to all susceptible patients with chronic liver disease. In , a total of 12, cases of hepatitis A were reported in the United States, but due to underreporting, the actual number of cases is likely around 24, 1.

Reported cases have increased dramatically since , when large person-to-person outbreaks began occurring. Although viremia occurs early in infection, current data indicate that bloodborne transmission of hepatitis A virus is uncommon. Although anyone can get hepatitis A, in the United States, certain groups of people are at higher risk for getting infected and for having severe disease if they do get hepatitis A.

Among older children and adults, infection is typically symptomatic. Symptoms usually occur abruptly and can include the following:.

The average incubation period for HAV is 28 days range: 15—50 days 9 , 10 , HAV can live outside the body for months, depending on the environmental conditions However, the virus can still be spread from cooked food that is contaminated after cooking. Freezing does not inactivate HAV. Adequate chlorination of water, as recommended in the United States, kills HAV that enters the municipal water supply 14,15, Transmission of HAV from exposure to contaminated water is rare Immunoglobulin G antibodies to the hepatitis A virus, which appear early in the course of infection, provide lifelong protection against the disease 5.

Vaccination with the full, two-dose series of hepatitis A vaccine is the best way to prevent infection. Hepatitis A vaccine has been licensed in the United States for use in people 1 year of age and older. Immune globulin can provide short-term protection against hepatitis A, both pre- and postexposure.

Immune globulin must be administered within 2 weeks after exposure for maximum protection. Given that the virus is transmitted through the fecal-oral route, good hand hygiene—including handwashing after using the bathroom, changing diapers, and before preparing or eating food—is integral to hepatitis A prevention.

Although no known harm is associated with giving hepatitis A vaccine to infants, the hepatitis A vaccine dose s administered prior to 12 months of age might result in a suboptimal immune response, particularly in infants with passively acquired maternal antibody 18 , The two-dose hepatitis A vaccine series should be initiated when the child is at least 1 year of age.

The U. Food and Drug Administration has licensed two single-antigen hepatitis A vaccines and one combination vaccine for use in the United States. All are inactivated vaccines. For detailed information on hepatitis A vaccine schedules, see Immunization Schedules for Children or Immunization Schedules for Adults.

The exact duration of protection against hepatitis A virus infection after vaccination is unknown. Hepatitis B, diphtheria, poliovirus oral and inactivated , tetanus, typhoid oral and intramuscular , cholera, Japanese encephalitis, rabies, and yellow fever vaccines can be given at the same time that hepatitis A vaccine is given In studies among young children, simultaneous administration of hepatitis A vaccine did not affect the immunogenicity or reactogenicity of diphtheria-tetanus-acellular pertussis; inactivated polio; measles, mumps, rubella MMR ; hepatitis B; and Haemophilus influenzae type b vaccines 26 , 27 , Ideally, doses of vaccine in a series come from the same manufacturer; however, if this is not possible or if the manufacturer of doses given previously is unknown, providers should administer the vaccine that they have available The dose should be considered valid and does not need to be repeated.

The second dose should be given as soon as possible. Even if the second dose is delayed, the first dose does not need to be repeated. Information regarding people who should not receive the hepatitis A vaccine is provided in the Vaccine Information Statement for Hepatitis A.

Pregnant women should be vaccinated for the same indications as non-pregnant women. Unvaccinated or partially vaccinated pregnant adolescents should receive catch-up hepatitis A vaccination. Pregnant women at risk for hepatitis A during pregnancy should also be counseled concerning all options for preventing infection.

Because hepatitis A vaccine is inactivated, no special precautions need to be taken when vaccinating people who are immunocompromised.

After completing the 2-dose vaccine series, most people who are immunocompromised do not need additional vaccine. The most frequently reported adverse events associated with monovalent hepatitis A vaccination are fever, injection site reactions, and rash. It is not known for how long protection from one hepatitis A vaccine dose lasts, but it has been shown to last for at least 10 years Prevaccination serologic testing for hepatitis A immunity prior to vaccination is not routinely recommended.

However, it may be considered in specific settings or populations when the cost of vaccinating people who are already immune is a concern.

People for whom prevaccination testing will likely be most cost-effective include adults who were either born in or lived for extensive periods in geographic areas that have a high or intermediate endemicity of hepatitis A. Vaccination should not be postponed if vaccination history cannot be obtained, records are unavailable, or prevaccination testing is not feasible.

Serologic testing for immunity is not necessary after routine vaccination of infants, children, or adults. Although hepatitis A vaccine is recommended for all children in the United States at age 1 year i. In the United States, floods, which may carry raw sewage, are unlikely to cause outbreaks of communicable diseases, and outbreaks of hepatitis A caused by flooding have not been documented Floodwater After a Disaster or Emergency.

Hepatitis A vaccine is not routinely recommended for health-care personnel, because health-care-associated transmission of hepatitis A virus is rare in the United States. Changes were made to the dosing instructions for hepatitis A pre- and postexposure prophylaxis indications. These changes were made because of concerns about decreased HAV immunoglobulin G antibody anti-HAV IgG potency, likely resulting from decreasing prevalence of previous HAV infection among plasma donors, leading to declining anti-HAV antibody levels in donor plasma Because common-source transmission to patrons is unlikely, PEP administration to patrons is typically not indicated.

However, PEP may be considered for those patrons potentially exposed to a symptomatic food handler if a the food handler directly handled uncooked or cooked foods without gloves AND had diarrhea or poor hygienic practices and b the patron can be identified and treated within 2 weeks of exposure, though the risk to these patrons still remains low In settings in which repeated exposures to hepatitis A virus might have occurred e.

PEP in this scenario should generally consist of vaccination for all age groups, though immune globulin may be considered for exposed people patrons during the time the food handler was symptomatic and worked who are immunocompromised or have chronic liver disease.

People who are immunocompromised or have chronic liver disease and who have been exposed to hepatitis A virus within the past 2 weeks and have not previously completed the 2-dose hepatitis A vaccination series should receive both immune globulin 0. When the dose of hepatitis A vaccine administered is the first dose the exposed individual has received, a second dose should be administered 6 months after the first for long-term protection.

Women with increased likelihood of exposure to HAV during pregnancy can be administered immune globulin 0. There has been no observed increase in maternal or infant adverse events after hepatitis A vaccination or IG administration in pregnancy.

All susceptible people i. These travelers should be vaccinated or receive immune globulin if too young or contraindicated for vaccine before departure 37 , People traveling within 2 weeks i. The hepatitis A vaccine series should be completed according to the routine schedule. Information on immune globulin dosing and additional information on hepatitis A vaccine and travel is available. Information on immune globulin dosing is available.

Hepatitis A vaccine should be administered to infants aged 6—11 months traveling outside the United States when protection against hepatitis A is recommended. This vaccine dose does not count towards the 2-dose series. The 2-dose hepatitis A vaccine series should then be initiated at age 12 months at any interval after the dose administered for international travel preexposure prophylaxis according to the routine, age-appropriate vaccine schedule.

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