(CNN) When Alexandra Leighton set out to get her Covid-19 vaccine, she found herself pleasantly surprised.
Leighton, who produces television commercials, found she could get any of the three Covid-19 vaccines -- Pfizer, Moderna or Johnson & Johnson -- within a reasonable drive from her Miami home.
"At the beginning it was horrible -- you wanted to get vaccinated, but they didn't have enough appointments," she said. "But I found places where you can get whatever vaccine you want. I was like wow, this is incredible."
Vaccine availability has improved even more since March, when Leighton got her shots. According to an analysis done May 4 for CNN by VaccineFinder, 78.8% of people in the United States live within 5 miles of locations that offer all three vaccines.
"People do have the ability to choose which vaccine is right for them. At this moment, there's an abundant supply, and people can make the choice for what is right for them personally," said John Brownstein, co-founder of VaccineFinder.
VaccineFinder powers Vaccines.gov, the federal government website where you can search for Covid-19 vaccines by ZIP code. Searches there show particularly easy access to all three vaccines for people who live in big cities, but even those who live in small towns have a choice of all three, although sometimes it might mean a bit of a drive.
For example, if you live in downtown Zebulon, North Carolina, population 5,917, you're a three minute drive to Zebulon Drug, where you can get either Pfizer or Moderna. Drive about five minutes and you can get to Walmart, which has Johnson & Johnson.
Even in the smallest city in Kansas -- Freeport, population 4 -- all three vaccines are available within an hour's drive. A Moderna or Johnson & Johnson shot is about 20 to 30 minutes away, and for Pfizer you can drive about an hour to Wichita. (These searches were done May 8, and availability could change.)
Brownstein, the chief innovation officer at Boston Children's Hospital, said he hopes people who are hesitant about getting a vaccine might feel differently once they see they have options.
"There are more opportunities and more choices for people who are on the fence," he said. "When you empower people to make decisions, I think for some people that will make a difference."
Brownstein said he personally was happy to get whichever vaccine was offered to him, since all three have been found to be safe and effective. But he understands that others might have preferences.
Leighton, for example, chose Pfizer after she watched a 45-minute National Geographic film, "Mission Possible: The Race for a Vaccine," about how it was developed. (The documentary "is paid content created for and in collaboration with Pfizer, Inc." according to the show's opening slate).
Others will have different criteria. Here's what we know about the safety and efficacy of each vaccine, based on the Phase 3 clinical trial data that each manufacturer submitted to the US Food and Drug Administration to obtain emergency use authorization.
How effective is Pfizer's vaccine?
Bottom line: In a clinical trial of more than 36,000 people, the vaccine was found to be 95% effective at preventing people from getting sick with Covid-19.
The details: In the clinical trial, 18,198 people received two doses of Pfizer's vaccine and 18,325 people received a placebo, which is a shot of saline that does nothing. Of those who received the vaccine, eight became ill with Covid-19, one of them severely. No one was hospitalized or died from Covid-19. Of those who received the placebo, 162 became ill with Covid-19, three of them severely, and two participants were hospitalized. No one died.
The ongoing Phase 3 clinical trial of Pfizer's coronavirus vaccine confirms it remains more than 91% effective for at least six months at preventing people from getting sick with Covid-19. Vaccine experts say protection likely lasts even longer than that.
Additionally, evidence outside of the clinical trial has demonstrated how the vaccine is performing in the real world. An analysis from the Israel Ministry of Health based on data collected between January 17 and March 6 shows that two weeks after the second dose, vaccine effectiveness was at least 97% in preventing symptomatic disease, hospitalizations and death. The analysis also found that the vaccine effectiveness was 94% in preventing asymptomatic Covid-19, where infections show no symptoms.
How safe is Pfizer's vaccine?
In any vaccine clinical trial, people in the vaccine group will get sick and sometimes even die for reasons that have nothing to do with the vaccine. In Pfizer's trial, the number of people who died after receiving the vaccine, two, was smaller than the number of people who died after receiving the placebo, four. Both participants who received the vaccine and died were over age 55 -- one went into cardiac arrest and the other had arteriosclerosis or hardening of the arteries. The FDA concluded that these deaths "represent events that occur in the general population of the age groups where they occurred, at a similar rate." In other words, it wasn't surprising that in a group of more than 18,000 participants, two participants that age would die from those causes.
The FDA determined that two participants who received the vaccine might have had non-lethal side effects. The first was a participant who experienced a shoulder injury -- with any vaccine, the needle can go into the wrong part of the shoulder and cause injury. The second was lymphadenopathy, or swollen nodes in the armpit on the opposite side of where they received the injection; the FDA said it was "biologically plausible" that this was associated with the vaccine.
Did people feel sick after getting their Pfizer shots?
Some of them did, and they were more likely to feel sick after the second shot. The most common complaints were fatigue, headache and chills. Participants under age 56 were more likely to feel sick after their shots than older people. Here's some data on how participants under age 56 felt after getting their second dose. We're including the placebo data because these are very common symptoms, and sometimes people experience them just because.
How effective is Moderna's vaccine?
Bottom line: In a clinical trial of about 30,000 people, the vaccine was found to be 94.1% effective at preventing people from getting sick with Covid-19.
The details: In the clinical trial, 14,143 people received two doses of Moderna's vaccine and 14,073 people received a placebo, which is a shot of saline that doses nothing. Of those who received the vaccine, 11 became sick with Covid-19, none of them severely. No one died due to Covid-19. Of those who received the placebo, 185 became sick with Covid-19, 30 of them severely, and one person died. The number of people hospitalized due to Covid-19 was not reported.
The ongoing Phase 3 clinical trial of Moderna's coronavirus vaccine confirms it remains more than 90% effective for at least six months at preventing people from getting sick with Covid-19. Vaccine experts say protection likely lasts even longer than that.
How safe is Moderna's vaccine?
In any vaccine clinical trial, some people in the vaccine group will get sick and sometimes even die from reasons having nothing to do with the vaccine they received. In Moderna's trial, the number of people who received the vaccine and died -- six -- was smaller than the number of people who received the placebo and died -- seven. The six people in the vaccine group died of a heart attack, cardiac arrest, a head injury, organ failure, suicide and the cause of one participant's death was not specified. The FDA concluded that none of these deaths were related to the vaccine.
The FDA had similar findings for non-lethal serious adverse events. According to the FDA, the number of serious adverse events in the study was comparable between the vaccine and placebo groups. Among the group that received the placebo, 153 had a serious adverse event. Among the group that received the vaccine, 147 had a serious adverse event, with the most common being irregular heartbeat, heart attacks, pneumonia, and blockages in lung arteries. The FDA concluded that the rates of these severe events was similar for the placebo and vaccine groups.
Did people feel sick after getting their Moderna shots?
Some of them did, and they were more likely to feel sick after the second shot. Here are the numbers for 14,677 people who received their second shot and 14,566 who received a placebo. We're including the placebo data because these are very common symptoms, and sometimes people experience them just because.
How effective is Johnson & Johnson's vaccine?
Bottom line: In an international clinical trial of about 40,000 people, the vaccine -- which is given in a single shot -- was found to be 66.1% effective at preventing people from getting sick with "moderate to severe/critical" Covid-19 28 days after the shot was given. However, some of the participants in that trial were in South Africa, where a variant rendered the vaccine less effective. Looking only at the 17,793 participants in the US trial, the vaccine was found to be 72% effective against "moderate to severe/critical" Covid-19 28 days after the shot was given.
The details: In the international clinical trial, 19,514 people received Johnson & Johnson's vaccine and 19,544 people received a placebo, which is a shot of saline that does nothing. Of those who received the vaccine, 117 became ill with Covid-19, 14 of them severely. Two were hospitalized and no one died from Covid-19. Of those who received the placebo, 351 became sick with Covid-19, 60 of them severely. Eleven were hospitalized and seven people died due to Covid-19.
In the US clinical trial, 9,119 people received Johnson & Johnson's vaccine and 9,086 people received a placebo. Of those who received the vaccine, 51 became ill with Covid-19, four of them severely. Of those who received the placebo, 196 became ill with Covid-19, 18 of them severely.
How safe is Johnson & Johnson's vaccine?
One person in the clinical trial who received the vaccine, a 25-year-old man, experienced a rare and dangerous blood clotting condition. After the vaccine was distributed, as of April 25, 2021, 17 more people -- out of nearly 8 million who received the vaccine -- also developed the condition, according to the US Centers for Disease Control and Prevention. Three of them died. Among the 17 people, 16 were women and one was a man. All were under the age of 60, according to the CDC's investigation.
According to a fact sheet from J&J, "Blood clots involving blood vessels in the brain, abdomen, and legs along with low levels of platelets (blood cells that help your body stop bleeding), have occurred in some people who have received the Janssen COVID-19 Vaccine. In people who developed these blood clots and low levels of platelets, symptoms began approximately one to two-weeks following vaccination. Most people who developed these blood clots and low levels of platelets were females ages 18 through 49 years. The chance of having this occur is remote. You should seek medical attention right away if you have any of the following symptoms after receiving Janssen COVID-19 Vaccine: Shortness of breath; Chest pain; Leg swelling; Persistent abdominal pain; Severe or persistent headaches or blurred vision; Easy bruising or tiny blood spots under the skin beyond the site of the injection."
In any clinical trial, some people who get the vaccine get sick and sometimes even die from reasons having nothing to do with the vaccine. In Johnson and Johnson's trial, five people who received the vaccine died. One death was due to pneumonia, one death was due to a lung abscess in a patient with HIV and one death was due to shortness of breath of an unknown cause. The cause for two deaths was not specified. According to the FDA, "these deaths represent events and rates that occur in the general population of individuals in these age groups."
Some of the participants had non-lethal serious events after receiving the vaccine, but it was at the same rate as the placebo group. In both groups, 0.4% had a serious adverse event. Appendicitis was the most common, occurring in six vaccine recipients and five placebo recipients. According to the FDA, these events were "infrequent" and "balanced" between the two groups "with respect to rates and types of events."