Vaccine Seasonal Timing

About Vaccine Seasonal Timing

The timing of vaccination campaigns affects their effectiveness. Northern Hemisphere influenza vaccination campaigns typically run in the autumn, before flu season usually peaks in winter. Vaccinating too early may result in waning immunity before the season ends. Vaccinating too late may leave people unprotected during peak transmission. For tropical countries with year round influenza, timing is less critical. RSV immunization programmes are timed around the typical RSV season. Maternal RSV vaccination programmes specify a window late in pregnancy, set by national authorities. Polio and measles campaigns in developing countries are timed to National Immunization Days when house to house vaccination reaches all children. Climate change may alter the seasonality of respiratory viruses, affecting optimal vaccination timing.