Information about the novel coronavirus (the virus that causes COVID-19) is constantly evolving. We will refresh our novel coronavirus content periodically based on newly published peer-reviewed findings to which we have access. For the most reliable and up-to-date information, please visit the CDC website or the WHO’s advice for the public.
Before 2020, the leading cause of death in Americans was heart disease. However, after the onset of the global coronavirus disease 2019 (COVID-19) pandemic, COVID-19 has soared past heart disease to become the leading killer in the United States (Woolf, 2021). Fortunately, we now have very effective vaccines available in the country to help combat this disease’s spread.
No vaccine is 100% effective and it’s still possible to develop COVID-19 even if you’ve been vaccinated and it’s even possible to spread it to others. But the vaccine reduces your chance of developing severe disease or requiring hospitalization, and it reduces the chance of dying from COVID-19. Because of how vaccines work, the more people that get vaccinated, the more effective the vaccine is at preventing disease. The more people that are vaccinated, the lower a person’s chance is of catching the virus, reducing the chance that they will spread the virus to others.
- The vaccines available in the United States are highly effective at preventing severe COVID-19, but no vaccine is 100% effective and it’s still possible to catch and transmit coronavirus, even if you have received the vaccine. The more people that get vaccinated, the fewer opportunities the virus has to spread. Getting vaccinated and avoiding situations in which you might catch or spread the virus (like large gatherings, or visits with people who are at risk for developing severe disease) are our best defenses against COVID-19. Monitor local guidelines to see the status of COVID-19 in your area.
Can you infect someone else after getting the vaccine?
To answer this question, it’s important to first understand that you cannot catch coronavirus from the vaccine itself. While you may feel a bit unwell after getting your shots, these are not signs of COVID-19. Rather, they are signs that your immune system is mounting a response that will help protect you from catching the virus if you are exposed in the future.
Since you cannot get COVID-19 from the vaccine, you can not pass it on to others from being vaccinated. The mRNA vaccines, like the ones from Moderna or Pfizer-BioNTech, only carry the viral genetic material that codes for a specific protein. They do not contain live viruses, so they cannot give you coronavirus. It is normal to have side effects like arm soreness, headaches, fatigue, and muscle aches after getting the vaccine—these are signs that your immune system is responding to the vaccine and preparing itself to prevent infection.
While it’s true that these vaccines are highly effective at preventing people from developing COVID-19, it is still possible to catch the virus if you’ve been vaccinated and it’s still possible to infect other people. That said, the risk is much lower. It is still important to mask up in places where you might be exposed to large crowds or when you’re around people who are at risk of developing a severe or deadly infection.
Additionally, it takes time for your immune system to be fully “trained” to respond to the COVID-19 virus. And even once you’ve been vaccinated, it’s possible that the effects of the vaccine wane over time. There is talk that COVID vaccines may be required annually to continue to prevent the spread of the disease, much like your annual flu shot.
In the meantime, make sure you get vaccinated and that all eligible people in your household get the vaccine as well. If you know you’ve been exposed to someone with COVID-19, it’s important to get tested and avoid infecting others. If you have symptoms of COVID-19, consult with your healthcare provider to decide if getting tested is the right option.
- Byambasuren, O., Cardona, M., Bell, K., Clark, J., McLaws, M., & Glasziou, P. (2020). Estimating the extent of asymptomatic COVID-19 and its potential for community transmission: Systematic review and meta-analysis. Official Journal Of The Association Of Medical Microbiology And Infectious Disease Canada, 5(4), 223-234. doi: 10.3138/jammi-2020-0030. Retrieved from https://jammi.utpjournals.press/doi/10.3138/jammi-2020-0030
- U.S. Food and Drug Administration (FDA) (2020a, December) Vaccines and Related Biological Products Advisory Committee Meeting – FDA Briefing Document: Moderna COVID-19 Vaccine. Retrieved on February 5, 2021 from https://www.fda.gov/media/144434/download
- U.S. Food and Drug Administration (FDA) (2020b, December) Vaccines and Related Biological Products Advisory Committee Meeting – FDA Briefing Document: Pfizer-BioNTech COVID-19 Vaccine. Retrieved on February 5, 2021 from https://www.fda.gov/media/144245/download
- Woolf SH, Chapman DA, Lee JH. (2021). COVID-19 as the Leading Cause of Death in the United States. JAMA. 325(2):123–124. doi:10.1001/jama.2020.24865 https://jamanetwork.com/journals/jama/fullarticle/2774465