BRIEF—Brazil launches world's largest campaign with fractional-dose yellow fever vaccine

Brazil yesterday launched a mass immunization campaign that will deliver fractional doses of yellow fever vaccine to residents of 69 municipalities in the states of Rio de Janeiro and São Paulo.

The strategic plan for the campaign was developed with support from the Pan American Health Organization (PAHO) and the World Health Organization (WHO).

It will be the world’s largest vaccination campaign, to date, using fractional doses of yellow fever vaccine.

Some 23.8 million people are expected to be vaccinated during the campaign, including 10.3 million in the state of São Paulo and 10 million in the state of Rio de Janeiro. The state of Bahia is expected to begin vaccinating on February 19 with an estimated target population of 3.3 million people to be reached with the vaccine.

The PAHO and WHO have provided wide-ranging support to the Brazilian government and to states in responding to yellow fever outbreaks since last year.

This has included supplying yellow fever vaccine, purchasing syringes through the PAHO Revolving Fund, disseminating recommendations based on the best available scientific evidence, acquiring special vaccination cards for fractional doses (as was used in the Democratic Republic of the Congo), and working in the field alongside the national and local authorities.