Vaccination of children against hepatitis B has historically dropped in Brazil

It is not news that there has been a decrease in vaccination coverage in Brazil in general in recent years. However, researchers from Observa Infância, from the Oswaldo Cruz Foundation (Fiocruz), warn of the historic drop in vaccination of babies against hepatitis B.

According to a study carried out in partnership with the Arthur Sá Earp Neto University Center (Unifase), the sequence of casualties in the protection of children under 1 year old against the disease dates back to 2019. In 2021, the index reached 76% and, in 2022, preliminary data point to an index of 75.2%. The North region is the most affected. In 2021, only 63.4% were immunized against the disease. In 2022, preliminary data indicate a slight increase to 67.5%. However, the index is still considered extremely low. The goal stipulated by the Ministry of Health for the vaccine is 95%.

— We saw a drop in coverage of all vaccines in children up to 5 years old, but that of hepatitis B was more pronounced and this caused us concern, because the drop in vaccination is followed by an increase in the incidence of a disease that can be very serious — says researcher Patricia Boccolini, coordinator of Observa Infância.

Also according to Bocconlini, the drop in vaccination coverage was already happening in the country before the pandemic, but the picture has been aggravated in the last three years.

— In the context of the pandemic, we saw the issue of social distancing as a complicating factor because parents and guardians stopped taking their children to health centers. There is also the issue of increased food vulnerability of many families in recent years, which makes vaccination a secondary concern – explains the researcher.

The reasons for the decrease in vaccination against hepatitis B outside the pandemic scenario are the same as for other vaccines: a false sense of security for some parents who think that the disease no longer poses a risk to their children; misinformation; increase in the number of multidose vaccines in the children’s calendar; fear of adverse reactions; and hours of operation of the stations.

The vaccination schedule against hepatitis B consists of four doses. The first should be administered in the maternity ward, within the first 12 to 24 hours of the newborn’s life. After that, the child should have another three doses at 2, 4, and 6 months of age. It is important to emphasize that the child will only be protected after completing all the doses.

Except for the injection received in the maternity ward, the other hepatitis B vaccines are combined. That is, they protect against various diseases per application. For older children, adolescents and adults who have not yet been vaccinated, the recommendation is three doses with an interval of one month between the first and second, and five months from the second to the third.

Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV), which attacks the liver. Infectologist Francisco Ivanildo de Oliveira Junior, medical manager at Sabará Children’s Hospital, explains that it is common for people to become infected and not develop symptoms. In those who develop acute symptoms of the infection, the most common are: yellowing of the skin and eyes, darker urine, nausea, fever, and stomach ache. However, 70% of cases heal spontaneously.

The problem is the other 30% in which the disease evolves into the chronic form, where there may be cirrhosis and even liver cancer. If identified before progressing to these more serious consequences, chronic hepatitis B can be treated, but not cured.

— The drug helps to reduce the activity of the virus and can prevent liver failure. But they require continuous use. The person will need to take medicine their whole life – says the infectologist.

Prenatal care is essential

Hepatitis B is also considered a Sexually Transmitted Infection (STI). But the disease can also be transmitted by contact with blood and secretions. This means that an infected mother can pass the virus to her baby during pregnancy, childbirth or even while breastfeeding the child.

Therefore, currently, immunization is recommended not only for the baby at birth, but also for the woman during pregnancy. Vaccination at birth is important precisely to prevent chronic hepatitis, which affects 90% of babies infected at birth.

— This is a viral disease, silent, that the mother can be a carrier and not know. If contaminated intrauterine, the child may have fulminant hepatitis. If transmission occurs at the time of delivery, which is the most common, she may have chronic hepatitis and even liver cancer. In addition to being serious, this is absurd because there is a free and highly effective vaccine – says pediatric infectologist Ana Lucia Lyrio, professor of Medicine at Uniderp.

Therefore, specialists point out to mothers and fathers that, in addition to vaccination, a good prenatal care for the pregnant woman, with examinations for the detection of the disease, is essential to combat hepatitis B and its consequences in the child.

few side effects

Concern about adverse effects is one of the factors that keep parents from vaccinating their children. All vaccines currently in use are safe, but Oliveira Junior points out that the hepatitis B vaccine is “extremely safe”.

— It is a vaccine that has been part of the Brazilian vaccination schedule for 20 years. This vaccine is not made with live or inactivated virus. It is an extremely technological vaccine, made with genetic engineering, and with very little side effect – scores the doctor, explaining that the main adverse events are pain, hardening, swelling and redness at the application site.

To get around this scenario and increase vaccine coverage, there is no single strategy. There needs to be a joint effort that goes through clearly communicating that the benefits of vaccines outweigh the risks and that if vaccine-preventable diseases have disappeared, it is precisely due to the success of vaccination. The participation of schools is also important, from teaching the importance of prevention through vaccination for children to functioning as a place for vaccination, and expanding primary care and opening hours at health centers.