A simplified regimen for the prevention of mother-to-child
transmission of hepatitis B was just as effective as the standard preventive
regimen in pregnant women with very high virus levels and is likely to prove
easier to implement in resource-limited settings, Professor Calvin Pan of New
York University Grossman School of Medicine reported at the AASLD Liver Meeting
He was presenting results of a clinical trial carried out at
seven major hospitals in China, where vertical transmission of hepatitis B
remains a significant challenge.
The US-recommended regimen for the prevention of vertical
transmission consists of maternal treatment with the antiviral tenofovir disoproxil
fumarate (TDF) from week 28 of pregnancy if maternal viral load is above
200,000 IU/ml, combined with infant hepatitis B vaccination at birth, with
follow-up vaccine doses at weeks 4 and 24 postpartum, plus hepatitis B
immunoglobulin within 12 hours of birth.
The World Health Organization recommends maternal TDF from
week 28 of pregnancy if viral load is above 200,000 copies/ml, plus infant
vaccination. It also recommends an infant hepatitis B immunoglobulin dose where
this is available, especially in cases where the mother has a high HBV DNA
2020 guidance recognises that it is more challenging to deliver the hepatitis
B immunoglobulin dose after birth in lower-income settings, where it is costly
and often in short supply. According to GAVI, the global vaccine-funding
alliance, global coverage of HBV immunoglobulin is less than 13%
To test whether starting tenofovir treatment earlier in
pregnancy, without using hepatitis B immunoglobulin, would prove to be as
effective as standard treatment in preventing vertical transmission of
hepatitis B, US and Chinese researchers carried out a randomised study.
The study recruited pregnant women who were HBeAg-positive,
with hepatitis B DNA levels above 200,000 IU/ml and randomised them to receive
either TDF from week 14-16 of gestation or from
week 28 of gestation (control group). All infants received hepatitis B vaccine
within 12 hours of birth and at weeks 4 and 24 postpartum. Infants born to mothers
in the control group also received hepatitis B immunoglobulin.
The study enrolled 280 women. Two hundred and sixty-five
mothers and 269 infants completed the study. The median baseline HBV DNA level
was approximately 8 log10 IU/ml in each study arm.
At delivery, women in the intervention arm had been taking
tenofovir for a median of 23 weeks, compared to 11 weeks in the comparator arm.
There was no vertical transmission in either study arm. Women
in the experimental arm had significantly lower HBV DNA levels at delivery
((2.36 log10 IU/ml vs 3.63 log10 IU/ml; p < 0.001) and a higher proportion
had HBV DNA levels below 200,000 IU/ml (99% vs 94%, p = 0.04).
There was no significant difference in serious maternal adverse
events or adverse birth outcomes between the study arms.
The study investigators concluded that the intervention
regimen was equivalent to the current standard of care and that the preventive
regimen can be simplified safely, so that HBV immunoglobulin does not need to
be used in resource-limited settings.