![A young child receiving an oral polio vaccine.](/sites/default/files/styles/large/public/article18-19/17636_lores.jpg?itok=AqG4srb1)
Oral Polio Vaccine
![An 'Influenza Bulletin' from Ontario Emergency Volunteer Health Auxiliary.](/sites/default/files/styles/large/public/article18-19/30814685917_f074e71c2f_b.jpg?itok=CF-ihkiD)
Influenza Bulletin
![A public health campaign poster from the 1920s that sought to end the spread of Influenza and TB.](/sites/default/files/styles/large/public/article18-19/TB_poster.jpg?itok=l1XtbcVB)
Public Health Poster
![Dr. Gary Noble draws blood from his patient to test for antibodies to the H1N1 strain of influenza, 1976.](/sites/default/files/styles/large/public/article18-19/14849_lores.jpg?itok=F9dHS4iC)
Influenza Inoculation Program
![A National Guardsman assists with a drive through testing site for COVID-19 in Louisiana, 2020.](/sites/default/files/styles/large/public/article18-19/200326-Z-VU198-1060.jpg?itok=jCdIIIsu)
A COVID-19 Drive Through Testing Site
![Poliovirus (left), Influenza (center), and COVID-19 (right).](/sites/default/files/styles/large/public/article18-19/2020-06-05%20%282%29.png?itok=6KS94sVa)
Deadly Companions
![A house in Des Moines, Iowa sharing messages of encouragement to passing cars.](/sites/default/files/styles/large/public/article18-19/49706185972_e94ff6328c_c.jpg?itok=Q3jUxowD)
We Are In This Together
!['Plague in an Ancient City' (1652-1654) by Michiel Sweerts.](/sites/default/files/styles/large/public/article18-19/Plague_in_an_Ancient_City_LACMA_AC1997.10.1_%281_of_2%29.jpg?itok=ElZIz9DO)
The Plague of Athens
![St. Sebastian pleads with Jesus for the life of a gravedigger afflicted by the Justinianic Plague.](/sites/default/files/styles/large/public/article18-19/Plaguet03.jpg?itok=CvyzJF63)
Saint Sebastian Interceding for the Plague Stricken
![The plague of Florence in 1348, as described in Boccaccio's Decameron.](/sites/default/files/styles/large/public/article18-19/The_plague_of_Florence_in_1348%2C_as_described_in_Boccaccio%27s_Wellcome_L0004057.jpg?itok=7KJou2Wr)
The Plague in Florence
![Francesco Rosselli’s 1480 "View of Florence" shows the city’s population decimated by the plague.](/sites/default/files/styles/large/public/article18-19/Francesco_Rosselli_-_View_of_Florence_with_the_Chain_-_WGA20082.jpg?itok=vibYQuaE)
Population Depletion of Florence
![Citizens of Tournai, in the present-day Netherlands, bury plague victims, 1353.](/sites/default/files/styles/large/public/article18-19/Doutielt3.jpg?itok=9WY-499C)
Burying Plague Victims
![An 1852 illustration from the magazine Punch showing where cholera was thought to spread.](/sites/default/files/styles/large/public/article18-19/Punch-A_Court_for_King_Cholera.png?itok=mxEugGu_)
A Court for King Cholera
![US Army Camp Hospital No. 45 Aix-Les-Bains, France.](/sites/default/files/styles/large/public/article18-19/USCampHospital45InfluenzaWard-France-1918-USA-960.jpg?itok=IQiY-7yy)
Army Camp Hospital Flu Ward
![Two public health technicians carry out a vaccination campaign inside a Dekalb County, Georgia.](/sites/default/files/styles/large/public/article18-19/20117_lores.jpg?itok=AYPdhmt9)
Vaccine Program
![The 1990 ACT-UP protest at the National Institutes of Health.](/sites/default/files/styles/large/public/article18-19/14172919087_c1d1c5406f_b.jpg?itok=iOKDetVT)
ACT-UP Protest