Hepatitis B vaccination in HIV. The more the better?

In a randomized study from Thailand of hepatitis B vaccination
in 132 HIV-positive individuals, standard vaccination with
three doses of 20 μg was given at months 0, 1, and 6 was compared
to two other schedules. The second group received 20
μg at months 0, 1, 2 and 6. The third group received 40 μg at
months 0, 1, 2 and 6. All participants had CD4 cell counts above
200 and had undetectable HIV viral loads. After a median of
48.7 months, the response rate with anti-HBs > 10 mIU/ml was
57.1 % in the standard group, 76.7 % in the group that received
4 doses and 80.5 % in the group that received 4 double doses.

Ref; Chaiwarith et al. AIDS Res Ther 2019; DOI: 10.1186/s12981-019-0249-8

Comment: Usually, anti-HBs titers are measured about one
month post-vaccination and an anti-HBs titer of >10 mIU/ml is
considered to be protective. It is well known that the anti-HBs
titers may gradually decrease. In the present study, anti-HBs titers
were measured after a median time of more than 4 years. It
is obvious and not surprising that vaccination with four doses
and higher antigen content will achieve higher response rates
and higher titers than standard vaccination. There is no clear
recommendation to use other vaccine schedules in HIV-positive
individuals than in the general population. It is also not
clear if revaccination should be recommended in responders
with titers above > 10 mIU/ml whose titers decrease below the
threshold.