Review: Plasma-derived hepatitis B vaccine is safe and effective for health care workers
ACP J Club. 1998 Mar-April; 128:45. doi:10.7326/ACPJC-1998-128-2-045
Jefferson T, Demicheli V, Deeks J, et al. Vaccines against hepatitis B in health-care workers. In: The Cochrane Database of Systematic Reviews. The Cochrane Library. Oxford: Update Software; 1997; Issue 3.
To determine the effectiveness and safety of hepatitis B vaccine for health care workers.
Studies were identified from a MEDLINE search from 1979 on, a full-text search of all issues of the journal Vaccine to the end of 1995, bibliographies of retrieved papers, and correspondence with manufacturers and experts.
Studies were selected if they were randomized trials that examined the effects (number of hepatitis B cases prevented and side effects) of plasma-derived vaccines or yeast-derived vaccines compared with placebo, control vaccine (vaccine against other diseases), or no vaccine in health care workers who were in direct contact with blood, blood products, stained body fluids, or tissues.
Data were extracted on vaccine type (plasma-derived or yeast-derived), dose, immunization schedule, population, ethnicity, antibody titer increase, acute and chronic cases of hepatitis B, length of follow-up, and systemic side effects (malaise, nausea, fever, arthralgias, rash, or headache) and local side effects (induration and soreness at injection site).
4 trials met the inclusion criteria, and all had low scores on a 4-dimension quality measure. Mean follow-up was 14.5 months. 3 trials involved workers in high-risk settings (dialysis units), and 1 trial involved workers in a low-risk setting. Data from the 3 trials involving high-risk settings were homogeneous, and meta-analysis was done. The 3 trials included a total of 679 participants who received plasma-derived vaccine and 652 who received placebo. There were 17 cases of acute hepatitis B in the experimental group compared with 50 cases in the control group (P < 0.005) (Table).
Plasma-derived hepatitis B vaccine reduces acute hepatitis B events in health care workers.
Source of funding: Ministry of Defense, Army Medical Directorate UK.
For article reprint: Reprints not available. For other information, contact Dr. T. Jefferson, Head of Unit, Ministry of Defense, Army Medical Directorate, Cochrane Vaccine Field, Keogh Barracks, Ash Vale, Hampshire GB-GU12 5RR, England, UK. E-mail email@example.com.
Table. Hepatitis B vaccine vs placebo in health care workers*
|Outcome||Hepatitis B vaccine weighted EER||Placebo weighted CER||RRR (95% CI)||Weighted ARR||NNT (CI)|
|Acute hepatitis B||3.0%||7.7%||67% (44 to 81)||4.7%||22 (15 to 41)|
*Abbreviations defined in Glossary; RRR, ARR, NNT, and CI calculated from data in article.
We know a fair amount about hepatitis B vaccines. We know that plasma-derived vaccines and yeast-derived vaccines generate excellent serologic responses and reduce the frequency of asymptomatic seroconversion; clinical illness; hepatitis B surface antigen (HBsAg) carriage; and even hepatocellular carcinoma in a wide variety of high-risk populations, including homosexual men, health care workers, Alaskan natives, neonates born to carrier mothers, and Asian and West African children. We know that serious side effects are uncommon and that vaccination is economically attractive for many populations (1, 2).
Against this background, what can we learn from the analysis by Jefferson and colleagues? First, we can more precisely estimate the risk reduction afforded by plasma-derived vaccine in one high-risk group: health care workers. We also learn that plasma-derived vaccine seems to be safe in this group. These are useful, albeit modest, contributions to existing knowledge.
What about the methodologic shortcomings of trials considered in the analysis? Although details of randomization and blinding were poorly reported, the major shortcoming was the lack of serologic surveillance. Thus, the absolute risk reduction for seroconversion and, more important, HBsAg carriage are unknown (probably higher and lower, respectively, than clinical illness). No long-term efficacy data are available for health care workers, although long-term outcomes have been described in other high-risk groups (3).
This analysis supports existing evidence that hepatitis B vaccine is safe and effective in health care workers, as it is in other high-risk populations.
Murray Krahn, MD
The Toronto HospitalToronto, Ontario, Canada
3. Wainwright RB, McMahon BJ, Bulkow LR. Duration of immunogenicity and efficacy of hepatitis B vaccine in a Yupik Eskimo population: preliminary results of an 8-year study. In: Hollinger FB, Lemon SM, Margolis HS, eds. Viral Hepatitis and Liver Disease. Baltimore: Williams and Wilkins; 1991:762.