Argentina, officially the Argentine Republic, is a country located mostly in the southern half of South America. Sharing the bulk of the Southern Cone with Chile to the west, the country is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south.
With a mainland area of 2,780,400 km2 (1,073,500 sq mi), Argentina is the eighth-largest country in the world, the fourth largest in the Americas, the second largest in South America after Brazil, and the largest Spanish-speaking nation by area.
Argentina claims sovereignty over part of Antarctica, the Falkland Islands, and South Georgia and the South Sandwich Islands.
China is the third largest country in the world by area and the largest country in the world by population. Properly known as the People’s Republic of China, the political territory of the country includes the former nations of Tibet and Hong Kong. The capital is Beijing.
Cuba, officially the Republic of Cuba is a country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos.
Since 1965, the state has been governed by the Communist Party of Cuba. The country was a point of contention during the Cold War between the Soviet Union and the United States, and a nuclear war nearly broke out during the Cuban Missile Crisis of 1962.
Culturally, Cuba is considered part of Latin America.
Donald John Trump was the 45th President of the United States. Before entering politics, he was a businessman and television personality. Trump was born and raised in Queens, a borough of New York City, and received a bachelor’s degree in economics from the Wharton School.
Russia, or the Russian Federation, is a transcontinental country located in Eastern Europe and Northern Asia. It extends from the Baltic Sea in the west to the Pacific Ocean in the east, and from the Arctic Ocean in the north to the Black Sea and the Caspian Sea in the south.
Russia spans more than one-eighth of the Earth’s inhabited land area, stretching eleven time zones, and bordering 16 sovereign nations. Moscow is the country’s capital.
The Soviet Union was dissolved in 1991 and since 1993 Russia been governed as a federal semi-presidential republic. Russia is a major great power, with the world’s second-most powerful military, and the fourth-highest military expenditure. As a recognised nuclear-weapon state, the country possesses the world’s largest stockpile of nuclear weapons.
The United States is a country also known as the United States of America, USA, US or just America. There are fifty states in the union, which is a federal republic ruled by a representative democracy. Nearly ten million square kilometres are inhabited by over 300 million people. The majority of Americans speak English.
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.