You may have been familiar with the word ‘vaccine’ by now, especially after the COVID-19 outbreak that has caused many people to get the vaccine as means of protecting themselves against the virus. Vaccine helps the body to build protection against diseases by producing antibodies to fight against the respective disease. Diseases that are usually prevented by vaccines are typically the one that is easily spread. Vaccination boosts the body’s natural immune response against the disease. Even after vaccination towards the disease, a person might still need to get tested for the disease to evaluate their immune system against the respective disease.
To answer the question of “who should be tested for anti-HBs after vaccination”, it is best to understand things related to the anti-HBs first. Anti-HBs is among the tests used to test for hepatitis. Hepatitis is the inflammation of the liver. Liver is a vital organ that performs functions such as removing waste products from the bloodstream, regulating blood sugar levels, producing essential nutrients and fighting infections. Thus, when the liver is inflamed or damaged, these functions will be affected. The most common types of viral hepatitis are hepatitis A, B and C. Many people with hepatitis do not have symptoms and they might not even know they are infected.
Back to the question of anti-HBs, anti-HBs test is common in understanding those affected with hepatitis B. In Malaysia, it is estimated that more than 400 000 people are affected with hepatitis B. According to World Health Organization (WHO), it is estimated that more than 887 000 people die from hepatitis B resulted from cirrhosis (scarring of liver) and hepatocellular carcinoma (primary liver cancer).
Anti-HBs is also known as Hepatitis B surface antibody. The presence of anti-HBs is generally interpreted as recovery and immunity from previous hepatitis B virus infection. It also indicates that a person is protected against the hepatitis B virus in those successfully vaccinated against hepatitis B. Anti-HBs levels can dip over time in those completed vaccines against hepatitis B but the majority are still immune and will exert response when exposed to the hepatitis B virus. Those who acquire anti-HBs from immunisation will require a booster if the level falls below 100 mIU/mL.
There is a list of people who should be tested for anti-HBs. List as follows:
- Infants born to HBsAg positive mothers
- Persons who are HIV positive
- Haemodialysis patients
- Injection drug users
- Household, needle sharing, or sex contacts with persons who are HBsAg positive
- Men who have sexual activities with men
Anti-HBs is often tested with other hepatitis B parameters such as HBsAg (hepatitis B surface antigen) and anti-HBc (hepatitis B core antibody). Presence of HBsAg indicates that the person is infectious except when it might be transiently positive within 30 days after a dose of hepatitis B vaccine. Presence of anti-HBc indicates previous or ongoing infection with hepatitis B virus in an undefined timeline. People who have immunity to hepatitis B from vaccines do not develop anti-HBc.
Some might think that hepatitis B blood tests seem tedious as there are more than one parameters that healthcare professionals are looking for. Only one sample of blood is needed to check for hepatitis. Thus, do not be afraid or worried as it is easy to check for hepatitis B simply from just one sample of blood.
In general, it is important to get a hepatitis B test at least once in a lifetime for all adults aged 18 and above. Getting tested for the disease can help a person to get diagnosed early and to get the needed treatment. People who are positive for acute hepatitis B are usually treated through supportive care such as rest, fluid hydration and sufficient nutrition to alleviate symptoms. Acute infection appears from 2 weeks to 6 months of exposure to the virus with symptoms of fever, fatigue, loss of appetite, abdominal pain, nausea, vomiting, dark urine, light-coloured stool and yellowing tinge to skin or to the white eye (jaundice). People with chronic hepatitis B can be treated with antiviral drugs and are typically monitored regularly for progression to the liver disease. Symptoms of chronic hepatitis can take decades to develop.
The best way to prevent hepatitis is to take preventive measures:
- Maintain healthy weight
- Practise a healthy eating habits
- Avoid drinking excessive alcohol
- Do regular physical activity
- Avoid the use of illicit drugs
- Get immediate medical care if exposed to blood such as from helping people in road accident
- Avoid sharing individual items such as toothbrushes, razors and nail clippers
- Always wash hands before and eating food and after using the bathroom
- Use medicine in safe manner by following doctors instruction or as labelled on the medicine
- Practise safe sex which includes using contraception and limiting partners
- Get vaccinated against hepatitis is certainly the best way to prevent hepatitis