Seasonal Influenza Vaccine Uptake Among Health Care Workers Following Awareness and Availability of Influenza Vaccine Supply in Tertiary Care Hospitals, Bangladesh

Background :

Influenza annually affects a considerable portion of the world's population, causing significant health, social, and economic consequences. According to the World Health Organization (WHO) estimates influenza infects around 5-15% of adults globally. A collaborative multinational study in 2018 led by the US Centers for Disease Control and Prevention (CDC) found that between 291,000 and 646,000 people worldwide die from seasonal influenza-related respiratory illnesses each year.

Influenza has been a frequent cause of nosocomial outbreaks. Health care workers (HCWs) are at risk of influenza infection due to occupational exposure. In a systematic review of 26 studies and a meta-analysis of 15 studies found an increased risk of influenza among HCWs with a pooled prevalence rate of 6.3%, whereas it is 5.1% for healthy working adults other than healthcare workers. The attack rate among HCWs ranged from 18% to 24% during reported influenza outbreaks. HCWs may not only acquire but also transmit and spread influenza among hospitalized patients. HCWs often (40-83%) work while experiencing influenza-like illness (ILI), increasing the likelihood of influenza transmission to colleagues and patients.

Influenza vaccines are the most effective way to prevent infection and reduce the severity of the disease. Retrospective studies have shown correlations between increases in influenza vaccination among HCWs and decreases in nosocomial influenza in acute care settings. In 2012, the World Health Organization's Strategic Advisory Group of Experts (SAGE) on immunization recommended influenza vaccination for HCWs. WHO SAGE declared the highest priority risk groups in which healthcare workers are at the top of the list. Most developed countries have national policies on immunization against seasonal influenza; however, only 46% (64/138) of LMICs have one.

Despite the WHO vaccination recommendations and mounting scientific evidence on influenza burden and awareness, vaccination coverage rates remain low in LMICs. Persistently low rates of vaccine uptake among HCWs in most countries remain an international concern. Although a great response is seen after offering numerous measures to improve vaccination, the vaccination rate among health care workers remains insignificant. Several studies focused on vaccine uptake rates and associated factors with influenza vaccine acceptance and rejection have been conducted among HCWs in high-income countries in North America and Europe. Few studies have been conducted in LMICs (around 18 studies in sites such as Egypt, Vietnam, Jordan, Kenya, Sierra Leone, Malaysia, Turkey, Tunisia, Iran, China and Lebanon) on influenza vaccine uptake among HCWs. However, no reports are available, particularly from South Asian regions, including Bangladesh.