Expanded Hepatitis B Vaccination Coverage Associated With Improved Cost Savings, Life Expectancy in Ethiopia

Expanded hepatitis B vaccination coverage was associated with significant cost savings and improved life expectancy gains among health care workers of Ethiopia, according to study findings published in the Journal of Pharmaceutical Policy and Practice.

Hepatitis B virus (HBV) is a substantial global health burden that is primarily transmitted by percutaneous or mucosal contact with infected blood and body fuids, and through occupational exposure of health care workers during dental, medical, and surgical procedures.

An estimated 3%-5% of adults with acute HBV have a chance of progressing into chronic disease, which increases the risk of developing sequelae such as cirrhosis, liver failure, and hepatocellular carcinoma, as well as mortality due to liver complications. Health care workers, in particular, are 10 times more likely than the general population to acquire HBV.

Despite this, as well as the high endemicity of HBV in Ethiopia, only 14% of at-risk health care workers are currently immunized via a nonmandatory vaccination strategy in the country.

“World Health Organization (WHO) and the Ethiopian Federal Ministry of Health (FMOH) both encourage that all health care workers be vaccinated against HBV. These institutions have aimed to achieve HBV vaccine coverage of at least 80% among health care workers,” said the study authors.

“Unfortunately, a nonmandatory strategy is being used for vaccination against HBV in health care workers in the country. The burden of this viral infection is an additional challenge for Ethiopia’s health care system, which has been facing infectious and noncommunicable diseases.”

They conducted a cost-efectiveness analysis to determine the cost averted and disease prevention (life year [LY] gains) impact of increasing HBV vaccine coverage to 80% among all health care workforces, including nurses, laboratory, pharmacy, medical doctors, midwives, janitors, and supportive staff, compared with current nonmandatory vaccination coverage (14%).

A monovalent HBV vaccine, which has a 90% protection rate with a complete 3-dose series for lifelong protection, was used. Markov model for current coverage (14%) and expanding vaccination coverage to 80% (as per WHO recommendation) was simulated based on the data obtained from both primary and secondary data. Secondary data, particularly cost and effectiveness data, were gained from published articles, WHO guidelines, and Ethiopian Federal Ministry of Health documents.

Cost-related data for vaccination and chronic HBV treatment were also gathered by interviewing expertise from Tikur Anbesa specialized hospital. “We conducted the study from a healthcare payer perspective, with a 3% discount rate of cost and health outcome as recommended by the WHO,” explained the study authors.

The primary health outcome measured was the Incremental Cost-Effectiveness Ratio (ICER), with a deterministic analysis and tornado diagrams employed to manage parameter uncertainty and show a plausible range of cost and effectiveness of variables, they added.

Findings showed that expanded 80% coverage strategy provided 0.8 higher total LY gains (28.62 LYs) with a lower investment (US dollars [USD] 28.67) compared with the current nonmandatory vaccination coverage (14%) program, which was more expensive (USD 29.99) and garnered lower total LYs (28.54 LYs). The resulting ICER indicated that the expanded coverage averts the cost of USD 1.32 with the negative ICER value (USD-16.5 per LYs gain).

“The negative ICER showed that the expanded HBV vaccination strategy dominated the current vaccination strategy. A one-way sensitivity analysis also revealed that the current vaccine coverage was dominated by an increase in the risk of infection among unvaccinated individuals,” added researchers.

Due to a lack of country-specific data, viral transmission rates among study participants were not included, which might have underestimated the beneft of the findings. The lack of indirect costs related to increasing vaccination coverage, such as vaccine transport and cold chain equipment cost, were also cited as limitations.

“As long as expanding HBV vaccine coverage does not incur additional costs, and in the meantime, improves the healthy life of susceptible health care workers, Ethiopian FMOH should work on its implementation,” concluded researchers.

Reference

Tewuhibo D, Asmamaw G, Ayenew W. Cost-effectiveness analysis of current non-mandatory hepatitis B vaccination coverage vs expanding coverage among healthcare workers in Ethiopia. J Pharm Policy Pract. 2022 Oct 17;15(1):65. doi:10.1186/s40545-022-00458-4