Getting a flu shot each year is the best way to protect yourself, and this season you have a new option when it comes to flu prevention. Previously, the only flu shot available was a trivalent vaccine, meaning it protects against three strains of the disease.But now there's also a quadrivalent flu vaccine that protects against four flu viruses.ccording to the CDC, of the 135 to 139 million flu vaccine doses available this year, fewer than 32 million will be the quadrivalent vaccine. But experts agree that if the quadrivalent vaccine is not available in your area, go ahead and get the trivalent version.
There was nothing especially new about slavery as a system of labor and the exploitation of people when the Spanish and the Portuguese first began bringing slaves in 1503 from Western Africa to replace Native Americans in the gold mines of the Caribbean and Central America.
During the early 19th century, slavery expanded rapidly in Brazil, Cuba, and the United States, while at the same time the new republics of mainland Spanish America became committed to the gradual abolition of slavery. During the Independence Wars (1810â1822), slavery was abolished in most of Latin America.