Respiratory syncytial virus seasonality in Brazil: implications for the immunisation policy for at-risk populations

Freitas, André Ricardo Ribas; Donalisio, Maria Rita

There has been a great interest in studying RSV seasonality in order to develop appropriate prescription of palivizumab administration as well as other health care actions (Vieira et al. 2001 , Paiva et al. 2012 . In Brazil, palivizumab has been recommended based on the first studies regarding RSV seasonality, mainly performed in the South and Southeast states (ANVISA 2011). In 2013, the Brazilian Ministry of Health included palivizumab as a drug freely distributed by the Brazilian Public Health System for use in premature babies (gestational age less or equal than 32 weeks) and infants less than 2 years old with chronic lung disease or congenital heart disease with demonstrated hemodynamic repercussion. Every state and region can establish the optimal period for starting the use of immunobiologicals, accounting for the regional climate specificities and epidemiological evidences (MS 2012) . The recent revision of guidelines by the Ministry of Health in 2015 proposed a readjustment of the periods of provision of immunobiologicals in the different regions of the country (MS 2015). Our results reinforce this revision for provision of palivizumab in different regions, as suggested by others studies in Brazil (Vieira et al. 2001 , Paiva et al. 2012 ) and others regions (Panozzo et al. 2010 , Blom-Feshbach et al. 2013 . Results over the period for availability of palivizumab in the Midwest and Southeast (January) do not match exactly with those suggested by Ministry of Health (February). Although there are differences of one month only, these are densely populated regions. The readjustment of the immunisation schedule with palivizumab aims to ensure the protection of higher risk children, while avoiding the waste of this expensive immunobiological.