When Xiao Meng, a new mother, recently chatted with her sisters, she "heard" one thing - what? Also take your baby to check for hepatitis B antibodies?!
The importance of using artificial active immunization (that is, vaccination) to make the baby get immunity is very clear to new parents. Every newborn is vaccinated against hepatitis B within 24 hours.
But also to check whether the baby has obtained antibodies, most parents may not be very clear.
Not only that, in the case of hepatitis B prevention, it is not only "newborns" that need to check antibodies. Today we are going to nag about hepatitis B antibody screening.
01. Full immunization program for newborns with hepatitis B
First, let's review the hepatitis B vaccination procedure.
According to the guidelines for the prevention and treatment of hepatitis B and the guidance of doctors, the hepatitis B vaccine needs to be given 3 times throughout the process, according to the 0-1-6 months procedure, that is, after the first dose of vaccine, the second and third doses of vaccine are injected at an interval of 1 month and 6 months.
Newborns should be vaccinated against hepatitis B within 24 hours of birth, and the sooner the better. If the mother is herself a carrier of the hepatitis B virus, the newborn is also vaccinated with hepatitis B immunoglobulin.
02. Why do I need to check for antibodies?
The World Health Organization proposes that by 2030, the diagnosis rate and treatment rate of hepatitis B should reach 90% and 80% respectively, but according to relevant statistics, only about 10% of HBV infected people in the world know their infection and disease status, and the situation in the mainland is not optimistic, and the diagnosis rate and treatment rate are currently only 18.7% and 10.8%.
Since the introduction of the hepatitis B vaccine into the immunization programme in 1992, the mainland has made significant achievements in hepatitis B prevention and control, and has been reduced from high-endemic areas to moderate-endemic areas. However, there is still a long way to go in the screening, diagnosis and treatment of hepatitis B virus infection.
Many people think that after vaccination, they can rest easy, in fact, any vaccine does not achieve 100% protection.
According to statistics, after receiving the hepatitis B vaccine, about 5% of the population will still not produce antibodies. In other words, the protection rate of hepatitis B vaccine is only 90% to 95%, which is ineffective for a small number of people.
In addition, the protective efficacy of vaccines is not permanent. A large number of epidemiological surveys have shown that even if the hepatitis B vaccine is given at birth, more than 20% of children's hepatitis B antibodies disappear after 3-5 years.
A study by the Beijing Municipal Center for Disease Control and Prevention and the China Institute of Medical Information showed that the rate of hepatitis B virus infection in adults over the age of 20 was significantly higher than that of people under the age of 20. This trend also reflects the importance of hepatitis B antibody testing to some extent. As we age, the amount of antibodies in the body may gradually decrease.
Although the increase in chronic hepatitis B patients in mainland China has decreased in recent years with the advancement of prevention and control and treatment, the base of hepatitis B infection is very large, and it is estimated that there are still 84 million.
If the hepatitis B antibody is negative, and the immune memory of the cells is gone, it means that you are "naked" in the high prevalence area of hepatitis B and exposed to the risk of infection. Therefore, those with negative antibodies should be injected with hepatitis B vaccine booster injection as soon as possible.
03. When is the baby's hepatitis B antibody test?
Surface antibodies are water-soluble proteins that dissolve in the bloodstream and are delivered to the fetus through the placenta. After the baby is born, the antibodies from the mother can also survive in the bloodstream for about 6 months. Therefore, the surface antibodies detected after the baby is 7 months old can be determined to be produced by hepatitis B vaccine injection.
In general, if the hepatitis B vaccine is administered according to the normal immunization procedure for the hepatitis B vaccine, it is recommended to check the baby for hepatitis B antibodies at 9-12 months of age.
Serum HBsAg is generally positive for HBsAg within 2 to 3 weeks of hepatitis B vaccination, so it is recommended to perform quantitative tests for hepatitis B surface antigen and hepatitis B surface antibodies at least 1 month after the last dose of hepatitis B vaccine.
Surface antibody titers exceeding 10 mIU/ml indicate successful hepatitis B vaccination, and higher titers indicate stronger immunity.
04. Other people with hepatitis B antibody tests are recommended
From the perspective of health economics, early screening and diagnosis of hepatitis B infection and appropriate interventions have a higher cost-effective ratio; if hepatitis B infection is not detected in time, more medical costs will be spent on the treatment of diseases such as cirrhosis or primary liver cancer associated with hepatitis B infection in the future.
Because the hepatitis B vaccine does not completely block intrauterine infection, newborns born to HBsAg-positive pregnant women still have a 5% to 10% HBV blockade failure rate after vaccination.
Therefore, for women of childbearing age, hepatitis B screening should be carried out as early as possible, and the infection status should be judged in combination with other indicators to assess the need for antiviral therapy, thereby reducing the risk of pregnancy and improving the success rate of hepatitis B maternal and infant blockade.
Screening for hepatitis B virus serological markers can evaluate the effectiveness of vaccination in other high-risk groups, such as healthcare workers, people with frequent blood exposure, childcare workers, family members of hepatitis B virus carriers, gay men or polyamorous partners, intravenous drug addicts, and renal dialysis patients, and if serological markers are negative or low levels of anti-HBs, hepatitis B vaccine vaccination or revaccination may be given to enhance immunity.
For people over 16 years of age, booster immunization can be achieved with an optional 60 μg hepatitis B vaccine, which works with 1 dose.
Further reading:
In the past, making a hepatitis B vaccine required a blood supply from hepatitis B patients