***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: We included 13 trials with 567,476 participants randomised to pre- or post-exposure prophylaxis. The trials had high risk of bias. The trials were heterogeneous in terms of study setting, participants, interventions, and outcome measures. Our meta-analysis with six randomised trials showed that immunoglobulins, when used for pre-exposure prophylaxis, significantly reduced the number of adult patients with hepatitis A at 6 to 12 months (1020/286503 versus 761/134529; RR 0.53; 95% CI 0.40 to 0.70; random-effects model) in comparison with no intervention or inactive control. Four trials showed a similar effect in children aged 3 to 17 at 6 to 12 months follow-up (917/210822 versus 677/78960; RR 0.45; 95% CI 0.34 to 0.59). Comparing different doses of immunoglobulins, higher dosage was generally more effective than lower dosage (1.5 ml better than 0.75 ml and 0.75 ml better than 0.1 ml) in preventing hepatitis A. No significant systemic adverse events were reported. One trial showed that immunoglobulin was more effective than placebo for post-exposure prophylaxis. It appeared that there was no significant difference between immunoglobulins and inactivated hepatitis A vaccine in seroconversion to hepatitis A vaccine antibodies at four weeks (RR 1.16; 95% CI 0.98 to 1.38), but immunoglobulins were significantly less effective than vaccine regarding antibody levels at 8, 12, or 24 weeks. Immunoglobulins seem to be effective for pre-exposure and post-exposure prophylaxis of hepatitis A. However, caution is warranted for the positive findings due to the limited number of trials, year of conductance, and risk of bias. Conductance of rigorous trials will be justifiable.
Output:

This review concludes that immunoglobulins seem effective for preventing hepatitis A in both children and adults. However, the evidence, on which the conclusion is based, is not strong as the included trials appear to have risk of bias and their number is insufficient. Because there is a potential risk of blood-borne diseases from immunoglobulins preparations, such as human immunodeficiency virus, and because of the availability of hepatitis A vaccine, the use of immunoglobulins has become limited. However, their use is still required in some specific populations, such as persons with compromised immune function, children under one year of age, or persons who have not developed a full response to vaccine immunisation. Future clinical trials should address the benefit and harm of immunoglobulins in these populations.