Underinvestment in public health infrastructure is undermining jurisdictions' ability to protect their citizens, and misinformation from media and opportunistic political leaders are exacerbating vaccine hesitancy. In Brazil, immunization rates have been declining since 2016 for these very reasons.

Austerity measures have forced their system to abandon historic preventative immunization efforts, leading to a resurgence of vaccine-preventable illnesses, such as measles. And a lack of stable and effective leadership has chipped away at the country's ability to immunize as many of its citizens as it once did.

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But despite this, with nearly 85% of the population immunized with at least one dose, Brazil's Covid-19 vaccination rate is still among the highest in the world—higher than that of the U.S. or the U.K. Their story illustrates that the legacy of successful immunization campaigns outweighs efforts to undermine public faith in vaccines, and that public health systems help shape a culture of trust in institutions that can outlast any current political leaders' ideologies.

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Brazil's impressive track record of vaccinating its citizens is thanks in part to its National Immunization Program (PNI). The program was established in 1973 during Brazil's military dictatorship to boost domestic production capacity for vaccines, reducing reliance on other countries.

Within a decade of its launch, its mass immunization campaigns—which at one point inoculated 10 million people in one day—eradicated polio in the country and drastically reduced rates of other preventable diseases. And in the years following the collapse of the dictatorship, it became a hallmark of the Brazilian health system.  

The ongoing success of the PNI is tied to how the country's decentralized public health system, the SUS, operates. The SUS--Sistema Unico de Saúde or 'unified health system'—is the largest universal health care system in the world.

More than 75% of the Brazilian population, or 210 million people, rely on it exclusively for health care. Under this decentralized system, municipalities oversee primary care and the execution of immunization campaigns. The community-centric approach reduced regional and social inequalities, improved access to vaccines, and helped perpetuate the "inoculation culture" created through the PNI.

Brazil's relatively high uptake rate of the Covid-19 vaccine showcases the resilience of the country's institutions and the legacy of its historic approach to immunizations.