5 Facts About Covid Vaccines

Because it’s normal to have questions

Dr. Tom Frieden
Medium Coronavirus Blog
3 min readJun 8, 2021


Photo: Joshua Hoehne/Unsplash

For more than a year, most of the world has been outmatched by Covid. Now we have a powerful tool that’s the only way out of the pandemic: vaccines.

Covid vaccines were a true breakthrough, the result of dazzling scientific progress, substantial investment, and some plain old good luck. The vaccines are safe and more effective than many public health professionals dared to hope early in the pandemic. Covid vaccines were ready quickly, but they weren’t rushed — no corners were cut on safety in the development of these vaccines. Massive investment and more than 20 years of research on mRNA technology got us to where we are now.

Although vaccination can help us gain the upper hand against the virus, we still face some big challenges. First and foremost is lack of access — there’s simply not enough vaccine to meet global demands, and, tragically, we’re facing a dry patch in the coming months, just as the disease is roaring back in many parts of the world.

Supply has been concentrated in a small number of wealthy countries, leaving low- and middle-income countries behind. We must urgently step up global production of vaccines⁠ — especially mRNA vaccines⁠ — because uncontrolled spread anywhere in the world is a risk everywhere.

In the U.S., we have plenty of supply and most (63%) adults have now been vaccinated with at least one dose, but there’s still a lot of work to do to reach those still unvaccinated. Covid case counts are falling — and the more people we vaccinate, the fewer clusters and outbreaks we will see in the coming months.

Expanding access to vaccination will go a long way toward reaching the unvaccinated, but we also have to address the questions and concerns that are holding some people back. It’s normal to have questions, and we should treat everyone who has questions with respect. That means meeting people where they are, listening to their concerns, and doing our best to respond to them. These five facts about Covid vaccines could (hopefully) make the choice to get vaccinated easier for you or a loved one, friend, or acquaintance.

  1. The risks of infection are vastly higher than the risks of vaccination. Even healthy young people can become severely ill, die, or suffer long-term harm from Covid infection. Many people are struggling with “long Covid” symptoms such as fatigue, brain fog, headaches, loss of taste and smell, shortness of breath, joint or muscle pain, depression and anxiety, and more. Our team just published a deep dive into what we know about long Covid.
  2. Covid vaccines don’t stay in your body. The vaccines prime your system to fight the virus and then disappear. In contrast, if you get Covid, the virus will spread throughout your entire body, make billions of copies, and stay there for at least a week.
  3. Nearly every doctor who has been offered a Covid vaccine got it as soon as they could. Doctors and health care providers have a solid understanding of the science behind the vaccines, and many were deeply impacted by caring for Covid patients who became very ill or died.
  4. The more of us who get vaccinated, the faster we can get back our jobs and our economy. Places with less vaccine coverage face a higher risk of Covid clusters and possibly outbreaks — especially with the spread of more contagious variants — which will result in continued disruption to society.
  5. Vaccinations can save the lives of at least 100,000 Americans in the coming months who would otherwise be killed by Covid-19. They’ve already saved the lives of tens of thousands of people, many of them in nursing homes. We’ve tragically lost so many people already; we must do whatever we can to prevent even more deaths.

The vast majority of Americans who are hospitalized or dying from Covid right now are unvaccinated. Sadly, the virus reached them before the vaccine could. With the reduced spread of disease in almost every state and community in recent weeks, now is the time to get as many more people vaccinated as quickly as we can — before the virus has a chance to catch back up.



Dr. Tom Frieden
Medium Coronavirus Blog

President and CEO, Resolve to Save Lives | Former CDC Director and NYC Health Commissioner | Focused on saving lives. twitter.com/drtomfrieden