Get the hepatitis B vaccine to protect your precious liver!

Author: Wang Lin, Chief Physician, Children's Hospital, Capital Institute of Pediatrics

Vice Chairman of the Children's Health Branch of the Chinese Association of Preventive Medicine

Reviewer: Dong Jian, Chief Physician, Zhongshan Hospital, Fudan University

Vice Chairman of the Science Popularization Branch of the Chinese Medical Association

China used to be a country with a high incidence of hepatitis B. Over the past few decades, the National Center for Disease Control and Prevention has solved the hepatitis B problem for 200 million people in China through various efforts. For the Chinese population, hepatitis B vaccination is very important.

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After the country included hepatitis B vaccine in the routine immunization program for children in 2002, the hepatitis B virus carrier rate among children under 5 years old in my country has dropped significantly.

Hepatitis B vaccine is a compulsory immunization in the country and is also free for babies. Parents should vaccinate their babies as early as possible and in time to protect their health.

1. How to get the hepatitis B vaccine after the baby is born?

Under normal circumstances, the baby should receive the first dose of hepatitis B vaccine within 24 hours after birth, the second dose when the baby is one month old, and the third dose when the baby is six months old, which is commonly referred to as the 0, 1, 6 vaccination procedure.

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Are there any conditions that need to be met for the baby to receive the hepatitis B vaccine on the day of birth?

First of all, the baby must be relatively healthy, with a birth weight greater than 2500 grams, and no serious diseases such as birth asphyxia, hypoxia, jaundice, etc., before he can get the hepatitis B vaccine.

2. What adverse reactions may occur when babies receive hepatitis B vaccine?

Adverse reactions do not often occur when a baby receives the first dose of hepatitis B vaccine after birth, but they often occur after the third dose.

Adverse reactions can basically be divided into two categories, one is systemic reaction and the other is local reaction.

Systemic reactions, such as fever, irritability, crying, etc. Most babies may have systemic reactions to varying degrees, such as low fever, loss of appetite, and spitting up milk.

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Local reactions, such as redness, swelling and nodules at the needle hole, can also make the baby feel irritable because of the local pain and itching.

There are also some adverse reactions that are rare, such as diarrhea and abdominal pain.

How to deal with adverse reactions after babies receive hepatitis B vaccine?

For systemic adverse reactions, such as fever, the main treatment is symptomatic. If the body temperature exceeds 38.5℃, antipyretic drugs will be given. If the body temperature is not high, you can observe first.

For local reactions, if severe redness, swelling, or nodules occur, local symptomatic treatment should be carried out, including cold compress within 48 hours and hot compress after 48 hours.

Other adverse reactions such as lack of energy and spitting up may occur occasionally, so parents don’t need to worry too much. Generally, the baby’s spirit will return to normal 2-3 days after vaccination.

Generally speaking, the adverse reactions to hepatitis B vaccine in babies, especially the first dose, are not very serious, so parents don’t need to worry too much about whether the baby will experience serious adverse reactions because he is too young.

3. Can the hepatitis B vaccine be postponed?

Due to many factors, such as the baby being unwell, having a cold or fever, or something happening at home, or the parents forgetting, the baby cannot be vaccinated with the hepatitis B vaccine on the scheduled date.

At this time, parents may have various concerns: Can the second or third dose of hepatitis B vaccine be postponed? Will postponing the vaccination affect the effect? ​​How long can the vaccination be postponed at the latest?

In fact, delayed vaccination is not uncommon. A large amount of literature at home and abroad shows that short-term delays in vaccination will not affect the effectiveness of the vaccine, so parents don’t need to be particularly anxious.

How long is the short-term delay? In 2020, the National Center for Disease Control and Prevention, including the Beijing Center for Disease Control and Prevention, issued a plan for delayed vaccination. The plan shows that whether it is the basic dose or the third dose of the hepatitis B vaccine or the diphtheria, pertussis and tetanus vaccine, three injections can be given within 12 months with the same effectiveness.

Therefore, if the vaccination is delayed for one or two months, parents do not need to be too anxious. They can just get the vaccination as soon as possible at the appropriate time, but it is not recommended to delay for a very long time.

Finally, I would like to tell parents that it is best to check your baby after the hepatitis B vaccine, for example, when the child is one or two years old, to check whether hepatitis B surface antibodies have been produced. This is because about 5% of babies do not respond to the hepatitis B vaccine and do not have hepatitis B surface antibodies, so there is no protection and they may be infected with hepatitis B through various channels.

What tests can be done to know whether the baby has produced hepatitis B antibodies? A blood test for the five items of hepatitis B is enough. If the hepatitis B surface antibody is positive, it means that the vaccination is successful; if the hepatitis B surface antibody is weakly positive, it means that the antibody titer is not strong enough, and you can get another booster shot to strengthen it; if the hepatitis B surface antibody is negative, it means that the vaccination is unsuccessful and needs to be supplemented.