Yes. The vaccines are safe and they work.
You are less likely to spread the virus if you’re fully vaccinated. A growing body of evidence suggests that fully vaccinated people are less likely to have COVID-19 without symptoms and less likely to spread COVID-19 to others.
Millions of people have been vaccinated safely. The vaccines are working in the real world. Studies show them to be more than 90% effective in real-world settings in preventing mild and severe disease, hospitalization and death. The vaccines have also proven to be effective against the COVID-19 variants that are currently circulating in the country.
Some people who have gotten Johnson & Johnson vaccine have asked about also getting an mRNA vaccine. The vaccines in use in the U.S. are highly effective. If you are fully vaccinated, you are well protected, including from the variants currently circulating in the country, such as Delta. Since we have such high vaccination rates in Vermont, our level of protection is even higher. There is no data currently on how the Johnson & Johnson vaccine specifically would work with the other vaccines, so we can’t provide a recommendation at this time. But we will continue to monitor the CDC’s recommendations and share any new guidance as soon as it is available.
Learn about how mRNA vaccines (Pfizer and Moderna) work and how vector vaccines (Johnson & Johnson) work.
More about Vaccine Safety and Effectiveness
All three vaccines are safe and similarly effective at preventing severe illness and death. This standard is what is most commonly used to assess other vaccines like the flu shot. We cannot directly compare the efficacy of the three vaccines because they were not studied against each other at the same time. Each clinical trial had different study protocols, timing and location. For example, variants weren’t widely circulating when the earlier vaccines were being tested.
The CDC and FDA continue to assess the vaccines’ effectiveness as they are distributed. There are several things that can affect how well vaccines work in real-world settings (as opposed to clinical trial settings). The vaccines being administered now are going to millions of people, while trials enrolled tens of thousands each. The sheer number of people being vaccinated now may mean individual reactions that were different from those who participated in the trials. A vaccine’s effectiveness also depends on things like variants, the amount of virus in your community or differences in administering vaccines like dosing schedules and vaccine handling in different settings.
Years of research into vaccines have brought us to where we are today. Scientists began researching coronavirus vaccines starting with Severe Acute Respiratory Syndrome (SARS) in 2003 and Middle East Respiratory Syndrome (MERS) in 2012. When these viruses disappeared, the pressure to find a coronavirus vaccine decreased. When COVID-19 was identified, the global focus on eliminating this new coronavirus and ending the pandemic, combined with large amounts of funding, helped speed up the research process to create a safe and effective vaccine.
Here are the steps to make sure vaccines are safe and effective:
Step 1: Vaccine Safety
With a brand new vaccine, researchers give it to a small number of volunteers — usually 20 to 100 — to test for any serious side effects. This step also helps determine the right dose or amount of vaccine to use.
Step 2: Vaccine Effectiveness
Once they know a vaccine isn’t likely to cause any serious side effects, researchers then give it to hundreds of people to determine how well the vaccine works (or its effectiveness). Researchers continue to monitor for any short-term side effects.
Step 3: Double Check Safety & Effectiveness
This is the last step before researchers can apply for approval from the FDA and begin to use it. To make sure the vaccine is safe and effective for people across ages, ethnicities, genders, and other factors, they give it to tens of thousands of people. This uncovers less common side effects and confirms once again that it’s safe and works well for everyone.
Step 4: Continue to Check Safety & Effectiveness
Even after researchers have answered the big questions, they keep studying the vaccine. They gather longer-term data to make sure the vaccine continues to work well.
Sometimes, when a vaccine is urgently needed, researchers combine steps to speed up the approval process. This doesn’t mean that they’re skipping any important steps. It does mean researchers and public health organizations are working together at an extraordinary level to get a safe, effective vaccine to the people who need it the most.