The top COVID-19 vaccines, safety concerns, and health updates—all in one place.


With more than 236 million coronavirus infections—including 44 million cases and over 707,916 deaths in the U.S.—since the start of the pandemic, the race to distribute a COVID-19 vaccine to Americans is on.

To date, three vaccines are rolling out in America. And while Moderna and Johnson & Johnson are being distributed under emergency use authorization from the Food and Drug Administration (FDA), Pfizer received full FDA approval on August 23. This approval will make it easier to implement vaccine mandates, according to NPR, and it could ease hesitation around the vaccine. (Note that the full approval only applies to those 16 and older; kids ages 12 to 15 can still get Pfizer under emergency use authorization.)

Moderna and Pfizer have shown success rates of over 90 percent in real-world conditions, while Johnson & Johnson's single-shot vaccine is 72 percent effective in the U.S. The highly transmissible Delta variant may lessen the effectiveness of available vaccines, but they're still shown to prevent severe illness and death.

In recent news, Sweden and Denmark paused Moderna distribution for younger people. The pause applies to those born in 1991 and later in Sweden, and people below 18 years old in Denmark. Rare side effects, such as myocarditis (inflammation of the heart), are the reason behind the decision. The countries advise young people to get the Comirnaty vaccine from Pfizer/Biontech instead.

Also, federal health officials in the U.S. have recommended Pfizer vaccine boosters for people with advanced age or compromised immune systems, as well as those who work in high-risk environments. The Biden administration is considering Pfizer, Moderna, and Johnson & Johnson booster shots for all Americans eight months after full vaccination, but this is pending approval.

With all of the vaccine news, parents are wondering when, exactly, things will go back to "normal"—and what a vaccine could mean for their family. Here, the latest on vaccine development, safety concerns, what happens once you've been fully vaccinated, and everything you need to know about COVID-19 vaccines.

Vaccine Safety and Regulations

The FDA has strict regulations that must be met before a vaccine can be distributed to the general public. To ensure the safety and effectiveness of a vaccine, it must go through three phases:

  • Phase 1: Early stage clinical trials on 20-100 healthy volunteers to test the safety profile, dose effects, and any adverse effects. If no serious side effects are discovered, the vaccine can move to phase 2.
  • Phase 2: Testing on hundreds of volunteers to determine any short-term side effects or dose effects on different categories of people. If deemed safe, the vaccine can move on to final trials.
  • Phase 3: Hundreds or thousands of volunteers are tested to evaluate the vaccine's effectiveness. This is where the FDA discovers if the vaccine prevents disease when compared to a placebo test and allows researchers to learn more about its safety and any common side effects.

Once this rigorous testing is complete and a vaccine is distributed to the public, phase 4—where the widespread effectiveness or long-term effects are tested on a greater population—will begin. To be considered effective, the FDA says that a vaccine should protect 50 percent of recipients.

"This unprecedented period has called for innovation, speed, and efficiency in vaccine production," says Mobola Kukoyi, M.D., MPH, an emergency physician at Carle Foundation Hospital in Urbana, Illinois who has seen both pediatric and adult COVID-19 cases in the emergency room. "Understandably, this comes with a concern for safety. However, given the different regulatory checkpoints in the phases outlined above, a product is only approved if it meets specific guidelines. My advice to all would be to follow the science."

Vaccine Front-Runners

With dozens of vaccines under development worldwide, a handful have shown promise. These are the ones to know about:

1. Pfizer

On December 11, 2020, Pfizer—working with German company BioNTech and Chinese drugmaker Fosun Pharma—was approved for emergency use in the U.S. On August 23, 2021, it became the first COVID-19 vaccine to receive full FDA approval in America. The full approval applies to those 16 and up; children ages 12 to 15 can get Pfizer under emergency use authorization.

Pfizer is also including children between 6 months and 12 years in pediatric trials. In September 2021, Pfizer announced that its vaccine is safe and effective in children ages 5 to 11 years old. And in early October, it applied to the FDA for emergency approval for this age group; results are expected in the next few weeks. Kids as young as 6 months old may get the go-ahead shortly after that.

2. Moderna

Partnering with the National Institute of Allergy and Infectious Diseases (NAIAD), Moderna, a biotech company in Cambridge, Massachusetts, created the first vaccine to reach phase 3 testing. On December 18, 2020, Moderna became the second drugmaker to receive approval from the FDA for rollout for people ages 18 and up.

After receiving this emergency approval, Moderna started enrolling kids 12 and up in new trials and is now including children between 6 months and 12 years old. They recently announced that its vaccine is highly effective in adolescents ages 12 to 17, and they plan to apply for emergency use authorization for this age group soon. Younger children may be eligible to get the Moderna vaccine later this year.

In October 2021, Sweden paused Moderna distribution for anyone born in 1991 or later. And Denmark did the same for those 18 and younger. The countries cited an increased risk of rare side effects, such as myocarditis and pericarditis (inflammation of the heart), in young people.

3. Johnson & Johnson

With $500 million in backing from Operation Warp Speed, Johnson & Johnson's COVID-19 vaccine launched its phase 3 trials in September 2020, though trials were temporarily paused in mid-October after an "unexplained illness" in one of the volunteers.

Now Johnson & Johnson—whose single-dose vaccine is 72 percent effective in protecting against COVID-19 in the U.S., but is even more effective in preventing severe disease and may reduce spread of the virus—has been approved for emergency use authorization from the FDA.

On April 13, use of Johnson & Johnson's COVID-19 vaccine was paused after six women developed blood clots. Nearly seven million people had received the vaccine in the U.S. at that time, and the FDA and CDC called for this pause out of an abundance of caution. After looking into the blood clot cases—which ended up totaling 15 instances—the vaccine has been restarted with a warning label about the rare clotting disorder. All of the cases occurred in women; the majority (13 cases) were in women between 18 and 49 years old, says The New York Times.

In July 2021, the FDA attached a different warning to the Johnson & Johnson vaccine, saying it could cause an increased risk of a neurological condition called Guillain–Barré syndrome. Indeed, according to The New York Times, people who received the Johnson & Johnson vaccine have a three to five times higher chance of developing the condition than the general population. Still, the risk is low, and experts say the benefits of getting the vaccine outweigh the risks.

4. AstraZeneca

In collaboration with the United Kingdom's University of Oxford, British-Swedish pharmaceutical giant AstraZeneca was awarded $1.2 billion to get 300 million doses of its vaccine contender ready for the U.S.

AstraZeneca said on March 22 that it would apply for emergency use authorization by the FDA in the coming weeks, but new concerns over outdated information included with the vaccine's results caused setbacks.

5. Novavax

After a successful round of safe early clinical trials, Novavax, a Maryland-based company, has another vaccine to watch. Preliminary studies on monkeys and humans showed the production of virus antibodies, as well as killer T-cells, which can kill cells with the virus. Novavax has already begun phase 3 testing in the U.S..


Is the testing moving too fast?

"The speed which this vaccine was brought to market was unprecedented," says Kevin Kathrotia, M.D., neonatologist and COO of Millennium Neonatology in Charlotte, North Carolina who has cared for babies whose mothers have tested positive for COVID-19. "This is a testament to the herculean effort of scientists and doctors at multiple companies, research facilities, and some of the world's greatest universities." 

And while things are moving faster than usual—it usually takes years to develop a vaccine, and COVID-19 vaccines are set to be distributed within 24 hours of FDA approval—Dr. Kathrotia says that we should trust the clinical trial process and the fact that a drug brought to market is safe and works. "Having said that, I would wait to go completely back to normal until we see flattening and/or virtual elimination of the virus, which can lag full scale implementation of a vaccine."  

Who should get a COVID-19 vaccine?

After undergoing a strategic rollout to the public—with doses available first to health care workers, high-risk adults, and residents of long-term care facilities—states began broadening eligibility. Now all American age 12 and up are eligible to receive a COVID-19 vaccine.

Is it safe for children?

Vaccines that have been approved by the FDA should be safe, but many COVID-19 vaccine early clinical trials excluded children. After receiving emergency FDA approval, though, Pfizer and Moderna started enrolling kids 12 and up in new trials, and both are now including children between 6 months and 12 years.

On March 31, Pfizer announced that its vaccine is 100 percent effective in preventing illness in young teens and, on May 10, received emergency use authorization for 12- to 15-year-olds. Pfizer also applied for emergency use authorization for kids ages 5 to 11 in October, and they might do the same for younger children soon.

Along those lines, Moderna announced that two doses of its vaccine are 100 percent effective in children ages 12 to 17, and one dose is 93 percent effective. No major side effects were reported in clinical trials.

We'll know more about when children should receive the COVID-19 vaccine in the coming months as more testing is done. That said, the CDC and AAP strongly recommend that all children continue to receive their routine vaccinations during the pandemic.

Note: The CDC has reported rare cases of myocarditis and pericarditis (inflammation of the heart) in people under 30 years old who received Pfizer of Moderna. Most cases—which come with symptoms like heart palpitations, chest pain, and shortness of breath—have occurred in males after their second dose, and they usually resolve with treatment. The CDC is investigating further, and the FDA is urging an expansion of pediatric trials to further evaluate this rare side effect, but the organizations still recommend that everyone 12 and up get vaccinated.

Is it safe for pregnant women?

Organizations like the CDC and the American College of Obstetricians and Gynecologists recommend that pregnant women receive the COVID-19 vaccine, as the benefits of vaccination outweigh any possible risks.

More good news: A baby in Florida and a baby in Colorado have been born with COVID antibodies after their mothers received the vaccine during pregnancy. Early studies also point to protective antibodies being passed through the breast milk of those who have been vaccinated.

Is it safe for people with allergies?

Early Pfizer vaccine distribution in the U.K. sparked warnings that those with severe allergies should not receive the vaccine, but Americans with allergies have received the OK to get it—though they'll have to discuss with their doctors first and be monitored following vaccination.

"People that do report those types of anaphylactic reactions to other vaccines or injectables — they can still get the vaccine, but they should be counseled about the unknown risks of developing a severe allergic reaction and balance these risks against the benefit of vaccination," said Sarah Mbaeyi, a medical officer with the CDC's National Center for Immunization and Respiratory Diseases.

If you or your child have a history of allergic reactions, you should speak with your doctor before getting vaccinated.

How will I know if my family should get the COVID-19 vaccine?

According to the CDC, getting vaccinated may keep you from becoming seriously ill if you do get COVID-19. It may also keep those around you from becoming sick.

Health experts agree that families should let the vaccine data speak for itself once testing is complete. The FDA and government officials will share ongoing vaccination guidance, but you should check with local health officials and your doctor about your family's vaccine plan.

What's the deal with booster shots?

As the Delta variant spreads across America, experts are seeing waning immunity from the COVID-19 vaccines. This problem especially impacts immunocompromised people (about 3 percent of the adult population) who may not build sufficient immunity after receiving the shots. Pfizer booster shots are now available for those 65 and older, as well as anyone 18+ who has underlying medical conditions, works in a high-risk setting, or lives in a high-risk setting.

U.S. health officials might eventually recommend Pfizer, Moderna, and Johnson & Johnson booster shots to all Americans eight months after full vaccination. According to AP News, if approved, the booster shots will first be given to health care workers and older Americans, who received the vaccines first.

OK, I'm vaccinated—now what?

Finally some good news: New guidance from the CDC suggests that people who have been fully vaccinated can start to safely enjoy some of the things they've put on hold during the pandemic.

You're considered fully vaccinated two weeks after receiving the second dose of the Pfizer or Moderna vaccines or two weeks after receiving the single shot from Johnson & Johnson. Here's what you can do once that happens:

  • In May, the CDC said that vaccinated people can skip wearing masks and social distancing in any situation, indoors or outdoors, except when required by law or regulation. However, guidance changed in late July 2021, thanks to the rise of the Delta variant. The organization now recommends vaccinated people wear masks in public indoor spaces "in an area of substantial or high transmission." Wearing a mask is also important "if you have a weakened immune system or if, because of your age or an underlying medical condition, you are at increased risk for severe disease, or if someone in your household has a weakened immune system, is at increased risk for severe disease, or is unvaccinated." You'll also still need to wear masks on public transportation (like trains, buses, and planes) and in health care settings. Students and faculty should also mask in schools, regardless of whether they're vaccinated.
  • Resume domestic travel. You also don't need to get a COVID-19 test (unless required by your destination) or self-quarantine before or after travel.
  • Travel internationally without testing, unless your destination requires it. That said, "Fully vaccinated international travelers arriving in the United States are still required to get tested three days before travel by air into the United States (or show documentation of recovery from COVID-19 in the past three months) and should still get tested three to five days after their trip," says the CDC.