The question is always in the air: When could a COVID-19 vaccine be ready? Top health officials say the end of this year would be a best case scenario, according to a recent Associated Press report .
But scientists have never created a vaccine so quickly, and concerns about its effectiveness have arisen, as well. Worldwide, testing has recently started or is about to start for about a dozen potential vaccines. The most promising vaccine candidates are expected to move into larger tests this summer, the AP said.
How quickly those studies can determine whether the vaccines are safe and effective depends in part on how widely the coronavirus is still spreading. The studies will need to enroll 20,000 people or more for each vaccine candidate, with half of them getting the real vaccine and the rest getting a dummy shot. Then it’s a matter of waiting to see how many in each group become infected with the virus.
We thought it would be interesting to take a look back and see what life looked like as the polio vaccine was introduced and then how things progressed as the science continued to advance and develop. There was an injectable type of vaccine and an oral version.
Polio, by the way, is no longer a concern in the United States. Since 1979, no cases of polio have originated in the U.S. However, the virus has been brought into the country by travelers with polio. The last time this happened was in 1993, according to the Centers for Disease Control and Prevention .
Take a look at these photos, all copyright Getty Images, below.
Here's the original caption on this Getty Images photo: Albert Sabin, who developed an oral polio vaccine safely tested on 12,000,000 Russians, holds a large tissue culture bottle up to the light to look for effects of virus damage to cells growing in the bottle. These effects can sometimes be seen without the aid of a microscope. Despite the apparent success of Sabin's vaccine, many questions concerning it and other live-virus vaccines remain unanswered. In view of this, the U.S. Public Health Service has ruled that live-virus polio vaccines are not ready for licensing. (Getty Images)
Here's the original caption on another Getty image from Detroit: In a crucial safety test, special microscopes are used during the processing of National Foundation Poliomyelitis Vaccine at Parke, Davis & Co. in Detroit. Trained scientists examine tissue culture to make certain that no living virus is present in the vaccine. [Undated photo circa 1950s.] (Getty Images)
This poster features the CDC's national symbol of public health, "Wellbee," who is shown here encouraging the public to take an oral polio vaccine. The CDC used Wellbee in a comprehensive marketing campaign that used newspapers, posters, leaflets, radio and television, as well as personal appearances at public health events. Wellbee's first assignment was to sponsor the Sabin Type II oral polio vaccine campaigns across the United States. Later, Wellbee's character was incorporated into other health promotion campaigns including diphtheria and tetanus immunizations, hand-washing, physical fitness and injury prevention. This artifact can be found in the Global Health Odyssey. (©CDC/PHIL/CORBIS/Corbis via Getty Images)
In San Angelo, Texas, children in residential areas looked on as Texas Health employees sprayed DDT over vacant lots in the city to combat a recent increase in the number of polio cases. All theaters, swimming pools, churches, schools and public meeting places were closed. This picture was added to the Getty Images system in June 11, 1949. (Getty Images)
Here's another photo in which we'll let the original caption do the talking: Some of the hundreds of children who flocked to eight clinics in Houston for anti-polio shots await their turn with their mothers and relatives. Doctors in Houston are conducting a mass experiment in the prevention of paralysis from polio. Houston is one of the Texas cities hardest hit in the southwest. (Getty Images)
Dr. Jonas Salk gives an 8-year old boy a trial polio vaccine at the Frick Elementary School in Pittsburgh, Pennsylvania, in February 1954. (Getty Images)
A low-angle view of American scientist and physician Jonas Salk (1914 - 1995), wearing a white lab coat, smiling while holding up two decanters containing the anti-polio vaccine that he developed. (Getty Images)
Here's the original caption on a photo with a creation date of Feb. 3, 1954: Film star Judy Holliday, who was a polio victim as a youngster, shows a small vial of the new trial polio vaccine to Debby Dains, 4, a March of Dimes poster boy. The vaccine will be tested on more than a half-million second-grade school children throughout the U.S. starting this spring. Miss Holliday came through her experience with polio without damaging effects. (Getty Images)
An original caption from McLean, Virginia in April 1954: It's titled "First 'Shot' In War On Polio.'
As a nurse, two nurses aides and a doctor hold tight, one of the first of some 1,000,000 children in 26 states of the United States receives the new polio vaccine. Before the summer is over, children, such as Robert Henninger (above), in 171 areas comprising 45 states will have taken part in the $7,500,000 trial. About half this number will receive the "true" vaccine, while the rest will be given "false" injections of a harmless substance so a careful comparison can be made. (Getty Images)
Dr. Jonas Salk, the University of Pittsburgh scientist who discovered the anti-polio vaccine, receives a special citation from President Eisenhower at the White House in 1955. (Getty Images)
Another original caption: These youthful polio patients make the first contributions to the "flying vaccine bank," a 4-foot replica of the polio vaccine bottle, at an airline terminal prior to launching the "bottle" on a 10,000-mile air tour of the nation for the March of Dimes. The bank was put on a flight to Los Angeles by American Airlines, a sponsor of the tour, where West Coast polio patients will lead ceremonies the next day. (Getty Images)
An original caption from April 23, 1955: First- and second-graders at the Kit Carson School line up for Salk Polio vaccine shots. San Diego was the first community in the United States to start this spring's mass inoculation with the serum. (Getty Images)
From Jan. 20, 1956: An operative in the Glaxo Laboratories mixes three distinct strains of killed polio virus to prepare the final vaccine. (Getty Images)
An original caption from April 19, 1956 in Indianapolis: At the Eli Lilly and Company plant, in the finishing department, the bottles are labeled, put into individual cartons with package literature, and then place in shipping boxes marked "Rush" -- one finishing line cartons 40,000 nine-dose vials in an eight-hour day. (Getty Images)
An original caption: Because they will not be in the United States next January when the March of Dimes drive is opened, Prince Rainier III and Princess Grace of Monaco this week made advance contributions to the 1957 March of Dimes campaign. They are shown depositing their gift in a miniature "iron lung" coin collector, a symbol of tens of thousands for whom the Salk Polio Vaccine comes too late. This was the first of more than a million of the canisters to be displayed throughout the nation in January. (Getty Images)
Children receive the sugar cube polio vaccine in the early 1960s. (Getty Images)
The Alabama National Guard prepares to fly the polio vaccine from Birmingham during the epidemic of 1963. In the early 1950s, there were more than 20,000 cases of polio each year. After polio vaccination began in 1955, cases dropped significantly. By 1960, the number of cases dropped to about 3,000, and by 1979, there were only about 10. Image courtesy CDC/Mr. Stafford Smith. (Getty Images)
Here's the oral administration of the polio vaccine as this baby receives immunizations -- a 1977 photo at the Well-Baby Clinic in Dekalb County, Georgia. Image courtesy CDC/Meridith Hickson. (Getty Images)
One of the four remaining vials of polio vaccine dating from Oct. 12, 1955, along with the original packaging. The vials were given to Dr. Michele Carbone, PhD., of the Cardinal Bernadin Cancer Center at Loyola Hospital in Maywood, Illinois, by an Oak Park physician, who had refused to immunize children with the vaccine and had saved the vials for more than 40 years in his freezer. (Corbis via Getty Images)
A health worker immunizes a child against polio in the street of the old city of Kano during the National Immunization Days, Nov. 13, 2002, in northern Nigeria. The original photo caption reads: Nigeria is currently the greatest risk to polio eradication. In late 2003, immunization activities against polio were brought to a halt in the state of Kano, the last major polio reservoir in Africa, because of unfounded rumors, which suggested that the polio vaccine was not safe. Nigeria recorded 202 cases of polio in 2002, and 300 for the year 2003. Ninety percent of all cases are in the Muslim northern states, and among them, Kano has the worst record. (2002 Getty Images) The Associated Press contributed to this report.
