Global influenza vaccination levels remain low and the rate of growth is slowing, despite the increasing provision of vaccine supplies, according to two new studies.

Only 20% of countries have achieved vaccination of 15.9% of the population - a conservative threshold based on World Health Organisation (WHO) recommendations, says the first study, which is published in the journal Vaccine this week. It is based on data from 157 countries for 2004-2009 supplied by the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA).

Official vaccination recommendations alone do not drive higher coverage, the study finds. Rather, higher levels of seasonal flu vaccination are associated with public health policies which have a direct impact on patients, such as effective communication and reimbursement policies. These factors appear to be substantially more important than a nation’s development status as defined by the United Nations (UN), which does not seem to correlate directly to coverage levels, it adds.

Seasonal flu vaccine coverage needs to continue to grow strongly to meet the recommendations of public health authorities and organisations, say the authors. The global vaccine supply increased by more than 70% to 449 million doses during 2004-2009, but only 20% of the 157 countries included in the study reached the authors’ “conservative” 15.9% threshold level, which was based on WHO seasonable influenza immunisation recommendations for the elderly only and did not include other at-risk groups.

The study also found that vaccine provision is uneven globally, and that several less-developed nations - notably in Latin America – have achieved higher coverage levels than some more developed countries, particularly in eastern and southern Europe. 

But continuing and accelerating growth of uptake is essential to protect populations against the threat of flu, IFPMA emphasises and, it adds: "the opportunity exists to achieve this goal." 

Robust measures that connect directly with patients, such as the use of effective communications and financial support for vaccination, can improve the effectiveness of local immunisation policies, irrespective of countries' UN development status, it says.

A second study has been published this week based on IFPMA data. Appearing in the International Nursing Review, it shows that there is widespread support among health authorities around the world for immunisation of healthcare workers.

Public health authorities globally recommend and financially support seasonal flu vaccine for healthcare workers, and the proportion of countries supporting such immunisation is similar to that targeting "traditional" risk groups, the study finds. 

The IFPMA data used in this study surveyed 26 countries taken from each region, and it found that 88% of them recommended vaccination of healthcare workers against seasonal flu, compared with 92% recommending immunisation of such workers with chronic pulmonary, cardiovascular or metabolic diseases and 96% recommending vaccination of the elderly.

Notably, no clear correlation with nations' development status was found, with 83% of less-developed countries and 92% of more-developed nations recommending immunisation of healthcare workers. 

The importance of routine flu vaccination of healthcare professionals, to protect the workers, their families and colleagues and, most importantly, their patients, is emphasised by Dr Kristin Nicol, associate chief of staff for research at Minneapolis VA Medical Center and professor of medicine at the University of Minnesota.

“Seasonal influenza poses a serious threat, causing potentially life-threatening infections in seriously-ill patients and staff absences that can disrupt healthcare services and increase costs. In contrast, healthcare worker vaccination can enhance patient safety, reduce workplace absence and provide savings for healthcare organisations,” she says.

“Increasing immunisation rates is an important priority, and robust policy measures, such as education, providing easy access to vaccines and formally documenting workers’ vaccination status can help achieve this,” Dr Nichol adds.

IFPMA says it compiled the global flu vaccine supply data because no systematic information has been available to assess vaccine provision, nor the effect of immunisation policies, even though seasonal flu places a major burden on public health and over 40% of national governments recommend vaccination of at-risk groups.