When scientists set out to develop a vaccine for COVID-19, they hoped to create a shot that was at least 50% effective. That efficacy would be enough to get some control over the pandemic and work our way out of it.
As the clinical trials advanced, scientists were stunned to see the vaccines not only hit that 50% benchmark, but were far surpassing it. And when the shots started rolling out in the real world, the data held up.
The vaccines aren’t perfect — no vaccine is. But the COVID shots come pretty close. So much so that we’re already seeing some clear signs that the vaccines have the power to defang the coronavirus, allowing us to go out and safely resume living our lives again.
Here’s how we know the vaccines are working:
Infections are free-falling as vaccinations increase
We are now seeing the lowest number of COVID cases since June 2020. On May 26, the United States reported a seven-day average of 23,162 cases — that’s a huge drop (that’s still falling) from early January, when the seven-day average was 259,614.
Cases in the U.S. started declining when about 40% of the population was vaccinated with at least one dose, which happened around April 14, said Monica Gandhi, an infectious diseases specialist at the University of California, San Francisco. Infectious diseases experts call this moment the inflection point — when there was enough immunity in the population to change the tide of the pandemic.
Israel saw an inflection point early March, when 40% of the adult population became fully vaccinated. After the inflection points in Israel and the U.S., cases have steadily declined day after day, week after week.
“It takes a certain amount of vaccination for cases to start going down,” Gandhi said.
Hospitalizations and deaths are down
As soon as we started vaccinating the most vulnerable people in our population — the elderly and people with chronic health conditions — hospitalization and death rates plummeted.
“You started seeing the death and hospitalization rate come down once we got the majority of those over 65 vaccinated,” since they were the people who were most susceptible to severe disease, Gandhi said.
Clinical data showed us that the vaccines essentially take death and severe disease off the table, according to Lucy McBride, a practicing internal medicine physician in Washington, D.C. Real-world data shows the vaccines are highly effective at preventing people from being hospitalized or dying — even when there are variants.
“The real-world drop in hospitalizations and deaths is proof positive of the vaccines’ power against COVID-19,” McBride said.
Cases among kids are declining as more adults get vaccinated
Vaccines decrease transmission and reduce the viral burden within communities. This is the concept of herd immunity — when there’s enough immunity in a population, through previous infection and vaccination, there are fewer opportunities for a disease to spread.
“Even though children aren’t vaccinated, the way that the unvaccinated get protected in our society is increasing rates of vaccination or infection ― whatever it is ― immunity in the rest of us,” Gandhi said.
Vaccinated people directly exposed to COVID-19 aren’t getting sick
We often hear about rare breakthrough infections in people who are fully immunized, but we rarely talk about all the times vaccinated people didn’t get sick after they were directly exposed to someone infected with COVID.
Vaccines were rolled out in the middle of an ongoing pandemic, when infections were actively spreading. That’s never been done before. Because of that dynamic, a good portion of vaccinated people have likely been exposed to COVID-19.
Just look at the data: Of the over 123 million people who’ve been vaccinated, there have only been about 1,600 serious breakthrough cases reported. “Almost by definition, people were exposed,” Gandhi said. COVID is still spreading, but the vaccines are preventing tons of infections from occurring.
A Kentucky nursing home outbreak didn’t lead to serious illness for the majority of those who were exposed
There was an outbreak at a nursing home in Kentucky in which a handful of fully vaccinated and unvaccinated residents and staff members got COVID-19. It might not sound like a win for vaccines at first. But if you dig into the data, it’s clear the vaccines worked wonderfully.
The person who brought COVID into the facility was unvaccinated — a reminder to get your shots, McBride said. COVID spreads fiercely in close quarters like nursing homes, so outbreaks in these types of settings are to be expected. But even so, the vast majority of those who were vaccinated in the nursing home were well protected.
“The Kentucky nursing home story is another vaccine success story. The majority of residents who got infected after vaccination did not have symptoms or did not get sick,” McBride said.
The same happened with an outbreak on the New York Yankees
Last but not least, the Yankees outbreak: Eight players and staff members who had received the one-dose Johnson & Johnson shot tested positive for COVID-19 in mid-May. Of the eight people who got infected, only one developed symptoms; the other seven were asymptomatic (a sign the vaccines did their job). Even the person who was symptomatic had a pretty mild illness (another sign the vaccine did its job).
Many doctors say a positive diagnostic test doesn’t necessarily equate to an infection. The positive polymerase chain reaction (PCR) tests were probably just picking up on little bits of virus that their immune systems were clearing out (thanks to the help from the vaccines). According to McBride, the Yankees players and staff members could have gotten a lot sicker — and maybe even required hospitalization ― if they hadn’t been vaccinated.
Get those vaccines; they’re working. And the more people who take them, the better the results for all of us.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.