Hepatitis B vaccine
Vaccination
against HEPATITIS B consists of 3 injections at 1-month intervals and a booster
one year later.
It should be
vaccinated:
- People living
with HIV HBV, that is to say, carrying the hepatitis B
- Medical staff,
- Subjects with
multiple sexual partners,
- Homosexuals,
- Drug addicts,
- Newborns but
surrogate virus,
- All teenagers
before their first sexual intercourse.
We currently
have three vaccines:
- GENEVAC B
- Engerix B
- HB vax DNA.
Moreover, we
know that 5 to 10% of infected subjects of hepatitis B become chronic carriers
of the antigen and develop CHRONIC ACTIVE HEPATITIS with high viral
multiplication is stopped in 40% by the treatment interferon-alpha.
These were
vaccinated subjects with active viral replication reflected in the amount of
virus DNA in serum and the presence of HBeAg and HBsAg.
6 months after
vaccination, the viral DNA has completely disappeared from the serum of three
of the 14 vaccinated patients, the transaminase activity is normalized to a few
weeks later. In 4 patients, the viral multiplication halved in three months.
So, 50% of patients responded completely or partially to vaccination. Tolerance
has always been perfect.
It is hoped that
immunization a therapeutic effect in the carrier of hepatitis B chronic active.
This could be an adjuvant treatment with interferon protocol. A study on a
larger number of cases will be undertaken.
A new vaccine
strategy seems to have reached a consensus in 1995.
You can get
effective protection by two injections one month apart and a booster six months
later,
In early 1996, a
new recombinant vaccine against hepatitis B has been on the market: the HB VAX
DNA 5 micrograms / 0.5 ml. Currently it is available for infants and children
(other forms for adults will be available soon).
This vaccine is
closer to the natural antigen. This high degree of purity of the protein
vaccine provides immunization dose lower than that of other vaccines.
Two immunization
schedules are possible:
- 3 injections
at 0, 1, 6 months
- 4 injections
at 0, 1, 2, 12 months.
The first scheme
is more suitable for the vaccination of school-age children (vaccination done
in the school year). The second scheme, reserved for infants, simultaneously
with the Pentacoq.
Currently (May
1999) the Technical Committee on Immunization (CTV) and the Superior Council of
Public Hygiene of France (CSHPF) believe that there is more scientific
arguments for maintaining vaccination reminders at regular intervals
But for those at
risk (health professionals, patients may receive massive or repeated
transfusions, surrounding an infected person, or chronic carrier, sexual
partners of an infected person or chronic carrier)
. Attitude
should be adjusted according to the age at first vaccination.
- If the first
vaccination occurred before age 25, regardless of the immunization schedule, no
reminder to predict
- After 25 years
reminders provided must be made and a serological test performed 1-2 months
after the recall ..
If the anti-HBs
antibody is greater than 10 mIU / ml, there are no additional point to make.
If the rate is
less than 10 mIU / ml, this means that the immune response is insufficient and
it is necessary that the physician assesses the personal risk of the subject to
judge whether additional reminders.
Vaccination is
intramuscularly into the deltoid muscle or anterolateral thigh for infants.
Since September
1997, a new vaccine against hepatitis A and B has been developed. It allows
vaccinated against hepatitis A and B at the same time.
The vaccine
called Twinrix, is the first combined vaccine against hepatitis.
Knowing that
at-risk populations are almost the same for hepatitis A and hepatitis B, the
new vaccine is undeniable progress.
This vaccine
provides equivalent to two monovalent vaccines injected into two separate sites
protection.
Dual protection
is set up between 2 and 4 weeks after the first injection.
The safety of
this vaccine is excellent.
At 1 month,
seroconversion rates were 94% for hepatitis A and 70% for hepatitis B.
At 2
months, they are 99.5% for hepatitis A and 97.4% for hepatitis B.
After the third
injection, they are practically 100%.
In practice,
three injections should be performed:
- The first day
0
- The second D +
30,
- And the third
in J + 180
So two injections
one month apart and the third at 6 months.
This vaccine is
not yet in October 1997, reimbursed by social security.
It can not be
dispensed by the pharmacist with a prescription.
In October 1998
mass vaccination in schools has been suspended by the government, so better ask
any contrindications of family policy, in particular through a more precise
examination in families.
This does not
affect the essential vaccination that protects against possible cirrhosis and
even hepatocellular carcinoma (Cancer) in the long term.
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