Hepatitis A is a widespread viral infection that spreads through contact with infected faeces. In the United States and Australia, an effective vaccine has significantly reduced the number of cases, but outbreaks still happen due to unvaccinated people. Symptoms often include fever, tiredness, dark urine, and jaundice, mostly in older kids and adults. It’s most contagious two weeks before and a week after jaundice appears.
Generally, the vaccine against Hepatitis A is very effective. The effectiveness of this and any other vaccine also depends on various factors. Vaccine effectiveness is affected by several factors including: infectious agent, vaccine factors, and the host factors including age, sex, genetics, nutritional status, gut microbiota, obesity, and immune history.
Doctors diagnose it with a blood test. Usually, the illness goes away on its own, and supportive care is enough. Most people won’t have long-term liver problems.
Vaccination is recommended for kids aged 12-23 months and high-risk groups, like drug users, travellers to risky areas, prisoners, and those with liver disease or HIV. The vaccine can be used before or after exposure. If the vaccine isn’t an option, a shot called immune globulin can be used.
For travellers, the vaccine or immune globulin can provide protection in countries where hepatitis A is common. Recent recommendations suggest that anyone over 12 months old should get the vaccine if they’ve been exposed. Infants aged 6-11 months traveling abroad can also get the vaccine for protection, but this extra dose doesn’t count towards their regular vaccine series.
The vaccine is preferred for post-exposure protection over immune globulin because it provides longer-lasting and stronger protection.
Langan RC, Goodbred AJ. Hepatitis A. Am Fam Physician. 2021 Oct 1;104(4):368-374. PMID: 34652109.
Nelson NP, Link-Gelles R, Hofmeister MG, Romero JR, Moore KL, Ward JW, Schillie SF. Update: Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Postexposure Prophylaxis and for Preexposure Prophylaxis for International Travel. MMWR Morb Mortal Wkly Rep. 2018 Nov 2;67(43):1216-1220. doi: 10.15585/mmwr.mm6743a5. Erratum in: MMWR Morb Mortal Wkly Rep. 2019 Mar 08;68(9):233. PMID: 30383742; PMCID: PMC6319798.
