all for naught? Hepatitis B immunisation in persons not previously exposed to hepatitis B or with unknown exposure status

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From: binstock <binstock@...>

Were this a diving competition, the authors would have scored a 10

for their double-backflip inverse contrapositive gyrations:

" In people not previously exposed to hepatitis B, vaccination has

unclear effect on the risk of developing infection, as compared to no

vaccination. The risk of lacking protective antibody levels as well

as serious and non-serious adverse events appear comparable among

recipients and non-recipients of hepatitis B vaccine. "

1: Cochrane Database Syst Rev. 2008 Jul

16;(3):CD006481.<http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3058 & it\

ool=AbstractPlus-def & uid=18677780 & db=pubmed & url=http://dx.doi.org/10.1002/146518\

58.CD006481.pub2>

Click here to read

Links

Hepatitis B immunisation in persons not previously exposed to

hepatitis B or with unknown exposure status.

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Mathew%20\

JL%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_\

DiscoveryPanel.Pubmed_RVAbstractPlus>Mathew

JL,

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22El%20Dib%\

20R%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed\

_DiscoveryPanel.Pubmed_RVAbstractPlus>El

Dib R,

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Mathew%20\

PJ%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_\

DiscoveryPanel.Pubmed_RVAbstractPlus>Mathew

PJ,

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Boxall%20\

EH%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_\

DiscoveryPanel.Pubmed_RVAbstractPlus>Boxall

EH,

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Brok%20J%\

22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_Dis\

coveryPanel.Pubmed_RVAbstractPlus>Brok

J.

Department of Pediatrics, Advanced Pediatrics Centre, Postgraduate

Institute of Medial Education and Research (PGIMER), Chandigarh,

India, 160012. <mailto:jlmathew@...>jlmathew@...

BACKGROUND: The benefits and harms of hepatitis B vaccination in

persons not previously exposed to hepatitis B infection or with

unknown exposure status have not been established. OBJECTIVES: To

assess the benefits and harms of hepatitis B vaccination in people

not previously exposed to hepatitis B infection or with unknown

exposure status. SEARCH STRATEGY: Trials were identified from The

Cochrane Hepato-Biliary Group Controlled Trials Register, the

Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE,

EMBASE, LILACS,Science Citation Index Expanded (last search, March

2007). Additionally, we contacted experts and vaccine manufacturers,

and read through reference lists for eligible trials. SELECTION

CRITERIA: Randomised clinical trials comparing hepatitis B vaccine

versus placebo, no intervention, or another vaccine in persons not

previously exposed to hepatitis B (HBsAg negative) or with unknown

exposure status. DATA COLLECTION AND ANALYSIS: The primary outcome

was hepatitis B infection (detecting HBsAg, HBeAg, HBV DNA, or

anti-HBc). Secondary outcomes were lack of sero-protection, antibody

titre, clinical complications, adverse events, lack of compliance,

and cost-effectiveness. Dichotomous outcomes were reported as

relative risk (RR) with 95% confidence interval (CI), using

intention-to-treat analysis assuming an unfavourable event for

missing data. Sensitivity analyses based on methodological quality

(risk of bias), available data analysis, intention-to-treat analysis

assuming a favourable event for missing data, best-case scenario, and

worst-case scenario were conducted. MAIN RESULTS: Twelve trials were

eligible. All had high risk of bias and reporting was inconsistent.

Hepatitis B vaccine did not show a clear effect on the risk of

developing HBsAg (RR 0.96, 95% CI 0.89 to 1.03, 4 trials, 1230

participants) and anti-HBc (RR 0.81, 95% CI 0.61 to 1.07; 4 trials,

1230 participants, random-effects) when data were analysed using

intention-to-treat analysis assuming an unfavourable event for

missing data. Analysis based on data of available participants showed

reduced risk of developing HBsAg (RR 0.12, 95% CI 0.03 to 0.44, 4

trials, 576 participants) and anti-HBc (RR 0.36, 95% CI 0.17 to 0.76,

4 trials, 576 participants, random-effects). Intention-to-treat

analysis assuming favourable outcome for missing data showed similar

reduction in risk. Hepatitis B vaccination had an unclear effect on

the risk of lacking protective antibody levels (RR 0.57, 95% CI 0.26

to 1.27, 3 trials, 1210 participants, random-effects). Development of

adverse events was sparsely reported. AUTHORS' CONCLUSIONS: In people

not previously exposed to hepatitis B, vaccination has unclear effect

on the risk of developing infection, as compared to no vaccination.

The risk of lacking protective antibody levels as well as serious and

non-serious adverse events appear comparable among recipients and

non-recipients of hepatitis B vaccine.

PMID: 18677780