COVID Vaccine Benefits: Did the CDC Try to Bury Good News?

Americans love to hate vaccines. These days few medical topics generate as much anger, suspicion and outright hostility. That is why the latest evidence about COVID vaccine benefits may be hard for some people to swallow. Two large studies suggest that updated COVID shots helped keep people out of emergency rooms and hospitals and may even have prevented heart attacks, strokes and cardiovascular deaths in older adults.

What Happened to the Vaccine Study?

The most recent study in question was supposed to have been published in the CDC’s Morbidity and Mortality Weekly Report (MMWR) last March. The results were not worrisome or weird. They were in line with previous research.

The study was just published in JAMA Network Open on June 23, 2026.

Here is what the researchers were trying to learn:

“What was the estimated effectiveness of 2025-2026 COVID-19 vaccines against medically attended COVID-19 among adults aged 18 years or older in the US from September to December 2025?”

What, you may ask, is “medically attended COVID-19“? It means that these patients were seen either in an emergency department [ED], an urgent care [UC] center or a hospital. There were 85,725 such “encounters.”

Here’s the bottom line in the words of the authors:

“…among immunocompetent adults aged 18 years or older, receipt of 2025-2026 COVID-19 vaccination from September to December 2025 provided protection against COVID-19–associated ED/UC encounters and hospitalization compared with not receiving a 2025-2026 COVID-19 vaccine dose.

“Adults can reduce their likelihood of severe COVID-19–associated outcomes by obtaining a 2025-2026 COVID-19 vaccination.”

In other words, the COVID vaccine reduced visits to emergency rooms and urgent care centers. More importantly, the vaccines kept people out of the hospital.

How effective were the vaccines?

Compared with people who had not received a 2025-2026 COVID shot, vaccinated adults were:

• 50 percent less likely to have a COVID-related emergency department or urgent-care encounter
• 55 percent less likely to be hospitalized with COVID

In an accompanying editorial Dr. Natalie Dean, an expert in biostatistics and epidemiology, offered this perspective:

“It is critical that we continue to characterize and publish estimates of vaccine effectiveness in populations with changing immunity against evolving viral strains.”

She went on to tell the Washington Post (June 23, 2026) this about the CDC’s decision not to publish the research:

“There was no scientific reason to reject this paper. It had undergone internal review, and it clearly meets the standards of peer-reviewed science. It makes my colleagues on edge to see political interference in the scientific process.”

That does not mean the vaccine prevented every infection. It did not! Nor does it prove that protection would remain equally strong for an entire year. It does suggest, however, that the updated vaccine substantially reduced the likelihood that COVID would send an adult to urgent care, the emergency room or the hospital during the period studied.

For people at high risk of complications, that is not trivial.

Was This Vaccine Study Politically Inconvenient?

The controversy is almost as interesting as the findings.

Health and Human Services officials maintain that CDC decisions are based on scientific rigor rather than predetermined conclusions. One of the study’s authors, however, has publicly suggested that the findings may have been unwelcome because they conflicted with the current administration’s vaccine policies.

We cannot know the motivation of everyone involved. We can say that the paper passed peer review and was published in a leading medical journal, along with a commentary defending the basic methodology.

Readers can decide for themselves whether the study (JAMA Network Open on June 23, 2026) was scientifically inadequate or politically inconvenient.

More COVID Vaccine Benefits for the Heart?

The second study raises an equally intriguing possibility: Could COVID vaccination reduce cardiovascular complications after infection?

Most people think of COVID as a disease of the respiratory tract. That’s easy to understand. In the early days of the pandemic people were dying of respiratory failure. Concerns about ventilator shortages made headlines. But the SARS-CoV-2 virus also affects the cardiovascular system. It can attack blood vessels, impact blood clotting and damage the heart.

People who catch COVID face an increased risk of major adverse cardiovascular events, commonly abbreviated MACE. These include heart attacks, strokes and death from cardiovascular causes. If a patient also requires a heart stent or bypass surgery, that is often included under the MACE umbrella.

A new study in JAMA Internal Medicine, June 15, 2026 analyzed data from more than 1 million US veterans. The authors wondered whether the 2024-2025 COVID vaccine was protective as previous vaccines had been. They analyzed electronic health records and compared veterans who had received both COVID and flu vaccinations to those who had received flu shots alone.

Why use flu-vaccinated veterans as the comparison group? Presumably, that helped reduce the “healthy vaccinee” problem. People who seek vaccination may differ from people who avoid all vaccines in ways that affect their health. Comparing two groups who were both willing to receive influenza vaccination may make the groups somewhat more alike.

Veterans over 75 got significant cardiovascular protection from the COVID vaccine over the next 8 months. They had a 38% lower risk of COVID-associated MACE.

That sounds impressive, but relative risk can make a modest benefit appear larger than it is. The absolute difference was small: roughly two fewer cardiovascular events per 10,000 people during the study period.

Both numbers matter, though.

Applied to a population of one million people, the researchers estimated that vaccination could prevent approximately:

• 2,370 major cardiovascular events
• 1,580 deaths

Those projections are based on observational data rather than a randomized clinical trial, so they should not be treated as guarantees. Nevertheless, preventing even a small percentage of heart attacks, strokes and deaths can become important when millions of older people are at risk.

Putting Relative and Absolute COVID Vaccine Benefits in Perspective

People deserve both relative and absolute risk figures whenever possible. Saying that a vaccine lowered cardiovascular risk by 38 percent sounds dramatic. Saying that the absolute reduction was about two events per 10,000 sounds a lot less impressive.

Neither statement is wrong. The relative figure describes how much the risk differed between the two groups. The absolute figure tells an individual how uncommon the outcome was and how much vaccination changed that risk during the study period.

Pharmaceutical companies almost always prefer to promote their drugs using relative risk numbers, because they seem so impressive. As I have frequently mentioned, the maker of Lipitor (atorvastatin) advertised this statin-type cholesterol-lowering drug as reducing the risk of heart attacks by 36 percent. That was relative risk reduction. The company then described the absolute risk reduction this way:

“That means in a large clinical study, 3 percent of patients taking a sugar pill or placebo had a heart attack compared to 2 percent of patients taking Lipitor.”

More recently we have seen a TV commercial for Repatha (evolocumab).

In large letters the ad states:

“heart attack RISK REDUCED BY 27%”

In much smaller type it explains:

“In a study, patients not treated with Repatha® had more heart attacks (4.6%) compared to those treated with Repatha® (3.4%).”

So the absolute risk reduction was 1.2%.

At last count, physicians prescribed statins to over 50 million Americans. They believe that even a small absolute risk reduction is critical for overall heart health.

COVID Vaccine Benefits Differ Depending upon Vulnerability

For a healthy young adult with a low chance of severe COVID, the absolute benefit might be fairly small. For an 80-year-old with heart disease, diabetes or lung problems, avoiding a hospitalization, heart attack or stroke could be far more consequential.

Vaccination decisions should therefore take age, previous reactions, medical history, prior infections and individual risk factors into account. A one-size-fits-all slogan, whether “everyone must get vaccinated” or “no one should ever get vaccinated,” is not a substitute for thoughtful risk assessment and science.

Why COVID Can Be Hard on the Heart

Ask most cardiologists what causes cardiovascular disease and you will likely be told that “bad” LDL cholesterol is the primary culprit. And yet there is growing evidence that infection could play an important role.

Researchers have reported for decades that gum infection (periodontitis) increases the risk for cardiovascular disease (Periodontology, Nov. 23, 2023). Vaccination against shingles reduces the likelihood of experiencing heart attacks and strokes (Clinical Infectious Diseases, Aug. 9, 2025).

You can read more about “The Infection Factor: Rethinking Heart Disease and Dementia” at this link.

Stiffer Arteries After COVID-19:

A small study published in the Journal of Clinical Medicine revealed that arteries become stiffer after COVID-19 infection. The healthy, young volunteers had participated in laboratory studies before the pandemic began (Journal of Clinical Medicine, March 8, 2023). Researchers used the same protocols to measure arterial stiffness and central hemodynamics after the participants recovered from mild COVID infections. As a result, the volunteers basically served as their own controls.

None reported serious complications from their illness. However, the investigators found that two to three months after recovery, the volunteers’ arteries were significantly stiffer.

The authors concluded that there is

“a widespread and long-lasting pathological process in the vasculature following the mild COVID-19 infection.”

Arterial stiffness tends to increase with aging and may contribute to cardiovascular complications later in life.

Dangerous Blood Clots Show Up in a British Study:

A British study published in the journal Heart compared 20,000 COVID patients to similar people who had not been infected (Heart, Oct. 24, 2022). Those who had been diagnosed with COVID had three times the risk of a dangerous blood clot in the veins following recovery. That held even for those who had not required hospitalization.

People hospitalized with COVID were 28 times more likely to suffer a deep vein thrombosis, 22 times more likely to develop heart failure and almost 18 times more likely to have a stroke than uninfected individuals. The elevated risk was especially high in the first month after infection, but it may last for up to a year.

Los Angeles Sees a Rise in Heart Attacks:

A separate study published in the Journal of Medical Virology analyzed data from Cedars-Sinai Medical Center in Los Angeles (Journal of Medical Virology, Sept. 29, 2022). Although the rates of heart attacks had been gradually declining for several years before the pandemic, they rose sharply starting in 2020.

The increase was greatest in relatively young adults from 25 to 44. According to the researchers, the heart attack death rate is now 30 percent higher than expected in that age group. People over 65 are dying of heart attacks nearly 14 percent more often than expected. The scientists hypothesize that a combination of stress and virus-induced inflammation may account for these cardiac effects of COVID-19.

Studying the Coronavirus and the Heart

In one of the earlier studies, researchers analyzed MRIs of the hearts of 200 people (JAMA Cardiology, July 27, 2020). Half of them had recovered from COVID-19 and the other half were matched for age and sex but had not been infected.

They were young adults to middle-aged. The average age was 49. These were relatively healthy people. Many of the COVID patients had caught the infection while on ski vacations.

Of the 100 people infected with the coronavirus, 67 recovered at home. A third required hospitalization and only two required mechanical ventilation. 18 patients had no symptoms and 49 had “minor to moderate symptoms.”

What Were the Cardiac Effects of COVID-19?

The researchers found that more than three quarters of the recovered patients had structural changes in their hearts after infection.

These cardiac effects of COVID-19 included:

“…myocardial inflammation (defined as abnormal native T1 and T2 measures), detected in 60 patients recently recovered from COVID-19 (60%), followed by regional scar and pericardial enhancement. Findings on classic parameters, such as volumes and ejection fractions, were mildly abnormal.”

In addition to cardiac inflammation, many infected patients also had elevated levels of troponin, a biomarker used to detect cardiac damage from a heart attack.

The authors note:

“…our findings reveal that significant cardiac involvement occurs independently of the severity of original presentation and persists beyond the period of acute presentation, with no significant trend toward reduction of imaging or serological findings during the recovery period.”

What that means is that patients who were not all that sick from the coronavirus experienced heart damage. And the heart inflammation persisted after recovery from the infection. Many of these “recovered” patients experienced unusual chest pain, palpitations, shortness of breath and general exhaustion. When the heart muscle suffers such damage, the heart can no longer pump blood as efficiently as it should.

The Deadly Cardiac Effects of COVID-19

Another previous study looked at heart tissue in older people who had died from COVID-19 (JAMA Cardiology , July 27, 2020). More than half of them had high levels of the coronavirus in their heart tissue. It appears that the virus can set up housekeeping in the heart and start replicating itself.

An editorial in the same issue of JAMA Cardiology suggests that:

“These new findings provide intriguing evidence that COVID-19 is associated with at least some component of myocardial injury, perhaps as the result of direct viral infection of the heart.”

These cardiologists worry that the damage seen in these studies could foretell “new-onset heart failure and other cardiovascular complications.”

They state that:

“…we are inclined to raise a new and very evident concern that cardiomyopathy and heart failure related to COVID-19 may potentially evolve as the natural history of this infection becomes clearer.”

What Is the Future of Cardiac Effects of COVID-19?

At last count, roughly 800 million people around the world tested positive for COVID-19. The US had over 100 million cases and that could easily be an undercount. If the research published in JAMA Cardiology holds up, millions of people could have some degree of heart damage. That’s even if they were not very ill from the coronavirus.

We don’t know how long the inflammation will last. Unfortunately, studies suggest that it may cause ongoing cardiovascular trouble.

COVID Vaccine Benefits Do Not Erase Vaccine Risks

Acknowledging benefit does not require pretending that vaccines are risk-free. COVID vaccines can cause adverse reactions. Rare cases of myocarditis and pericarditis have occurred, particularly in adolescent and young adult males after mRNA vaccination. Other uncommon complications have also been reported with particular vaccine formulations.

Those risks deserve careful investigation and honest communication. People who have experienced a serious reaction should not be dismissed or ridiculed.

But the existence of vaccine injuries does not prove that vaccines killed more people than COVID, as some visitors to this website assert. Nor does it make evidence of protection disappear.

A fair assessment requires comparing the risks of vaccination with the risks of infection for a particular person. Age matters. Sex matters. Health history matters. The vaccine formulation and dose interval may matter. So does the likelihood that the virus will cause hospitalization, cardiovascular injury or death.

Scientific evidence becomes distorted when only one side of that equation is allowed to count.

The Evidence Many People Do Not Want to Hear

We understand why some readers no longer trust public-health authorities. During the pandemic, officials sometimes spoke with more certainty than the evidence justified. Recommendations changed. Legitimate questions were occasionally brushed aside. Political considerations appeared to influence messaging from several directions.

That history makes transparency more important, not less. If a study finds that a vaccine failed, caused harm or offered only marginal protection, the public must hear about it. If a well-conducted study finds that vaccination cut hospitalizations roughly in half, the public should hear about that too.

Suppressing inconvenient evidence is wrong regardless of which political faction finds it inconvenient. The two recent studies cited at the top of this post do not settle every argument about COVID vaccination. Both were observational, not randomized clinical trials. Neither tells us how long protection will last against future variants. Neither proves that every person should receive every booster offered.

They do, however, challenge the claim that updated COVID vaccines provide no meaningful benefit. The evidence suggests that vaccination reduced emergency visits and hospitalizations and may have provided modest cardiovascular protection for older adults.

That is good news, even for people who do not want to hear it.

What Do You Think About COVID Vaccine Benefits?

Have you received an updated COVID vaccine? Did you experience side effects? Do you believe government officials have been candid about both vaccine benefits and risks?

Please share your experience in the comment section below. We expect strong opinions, but we ask everyone to remain respectful. Evidence should not become the enemy merely because it challenges something we already believe.

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