What’s the Buzz

Can You Still Get COVID-19 After Being Fully Vaccinated?

person getting covid vaccine cartoon

If the year 2020 was all about the COVID-19 pandemic, then 2021 has been all about vaccinations. In what is a triumph of science, the vaccine breakthrough–a process that previously took years–was completed in a matter of months. New technologies like messenger-RNA were used for the first time to develop COVID-19 vaccines.

As more and more people get vaccinated, there is increasing optimism that we will put COVID-19 behind us, but there’s still a lingering worry on many people’s minds. News of breakthrough cases post-vaccination has raised questions about vaccine efficacy.

What do breakthrough infections indicate about the effectiveness of COVID-19 vaccines? Why do vaccinated people get COVID-19? And what can fully-vaccinated people do to stay safe? Please continue reading to learn more about catching the virus after being fully vaccinated against COVID-19.

What are breakthrough cases?

Some individuals still get Covid despite being fully vaccinated. Meaning, these individuals are infected by the virus and test positive after receiving both the first and second dose of the Pfizer BioNTech or Moderna vaccine or the single-shot Johnson & Johnson vaccine. In some cases, people develop symptoms and in other cases people are asymptomatic. Breakthrough cases have raised concerns about whether vaccines are effective at preventing COVID.

Are COVID-19 vaccines effective?

Clinical trials have shown that the three vaccines approved in the United States–Pfizer BioNTech, Moderna, and Johnson & Johnson–effectively prevent severe disease and death from Covid. The Pfizer and Moderna two-shot vaccines have efficacy rates of around 95% and the J&J single-dose vaccine has an efficacy rate of around 72% in the U.S. 

What do vaccine efficacy rates mean?

Many people think that a 95% efficacy rate for COVID-19 vaccines means you have a 5% chance of getting Covid. Or that 5 out of 100 fully vaccinated people will still get Covid. But these assumptions are not true.

The efficacy rate of a vaccine is calculated by comparing people who get the vaccine in clinical trials to people who get a placebo. An efficacy rate of 95% means that whatever your risk of getting Covid was before vaccination, it is now 95% lower. So, the clinical trials showed that vaccines reduce risk by 95 percent. The clinical trials also showed that COVID-19 vaccines are 100% effective in preventing death. Meaning, none of the people in the trials died after being fully vaccinated.

It is worth noting that the data in clinical trials is collected from a few thousand people and is used to judge the safety and efficacy of COVID-19 vaccines. Once the vaccines are approved for use, they can be studied among millions of people in the real world. It is not surprising to see some breakthrough cases when you’re vaccinating tens of millions of people. 

What can cause breakthrough infections?

Breakthrough infections are extremely rare. As of late April 2021, more than 95 million Americans had been vaccinated and the number of breakthrough cases that had been reported to the Centers for Disease Control and Prevention (CDC) was less than 10,000. This means only around 0.06% of fully vaccinated people contract the virus. 

What causes breakthrough infections in vaccinated individuals? According to infectious diseases experts, the real-world effectiveness of a COVID-19 vaccine may be reduced due to various reasons.

  1. Administration: The COVID-19 vaccine may not have been properly administered. For example, it may not have been stored at the required temperature or it may have been given in the wrong part of your arm or you may not have received the full dose. In such instances, the vaccine may not protect you fully against illness.
  2. Timing: Some people have tested positive around the time they were vaccinated. It could be that they contracted the coronavirus just before or after they got the vaccine dose. It takes 2 weeks for the body to build immunity after you get vaccinated. Therefore, a breakthrough case can occur due to exposure just around the time of vaccination.
  3. Immunity: A person with a weak immune system may not develop a robust response to a COVID-19 vaccine despite being fully vaccinated. Some medications can lower a person’s immunity. Also, older adults and people with preexisting medical conditions may have weak immunity (the CDC reports that around 40 percent of breakthrough cases have occurred in older individuals). However, it does not mean older adults will not benefit from vaccines. Most older people have an excellent response to COVID-19 vaccines and are fully protected after vaccination. 
  4. Variants: The coronavirus that causes the Covid illness undergoes mutations as it spreads through different parts of the world. This leads to the emergence of new variants of the virus. Some of these new variants may be more infectious and can potentially elude the protection offered by vaccination. Vaccine manufacturers are already working on improving COVID-19 vaccines to ensure vaccination offers protection against all known and emerging variants of the coronavirus.

Can COVID-19 vaccines reduce the spread of COVID?

Clinical trials and real-world data have shown that vaccination can greatly reduce virus transmission. The mRNA vaccines, Pfizer BioNTech and Moderna, in particular, can profoundly reduce the spread of the coronavirus after a person is fully vaccinated against COVID-19. 

This means once a large majority of people are fully vaccinated with the first and second dose, we can go back to most activities safely. However, it is still a good idea to be careful in closed spaces with poor ventilation or in crowded places where there could be a high number of asymptomatic virus carriers. 

How to tell the difference between vaccine side effects and COVID symptoms?

If you were recently vaccinated, you may experience some side effects of the vaccine, and some of your symptoms can be very similar to the ones you have if you get Covid. However, vaccine side effects are short-lived and typically last 1-2 days. Covid symptoms typically last longer. 

Also, vaccine side effects usually consist of injection site pain, fever, mild headache, minor aches and pains, and fatigue. They do not typically include symptoms of Covid such as cough, shortness of breath, or loss of smell. 

If you were recently vaccinated and have symptoms that last beyond a few days, it is a good idea to get a Covid test done and isolate until you get the results.

How long does COVID-19 stay on clothes? 

As the vaccination drive gains momentum and more people return to normal lives, it’s wise not to let your guard down. You should continue taking preventive measures such as washing your hands regularly, wearing a mask (especially in poorly ventilated or crowded places), and maintaining a safe distance from other people who may not have been vaccinated. 

But what about clothes? Do you need to change and wash your clothes immediately after you get home? Scientists estimate that the coronavirus can remain on fibers that absorb moisture for 24 hours or longer. The virus can survive even longer on non-absorbent parts of clothes such as plastic buttons. 

It’s best to take precautions if you have known exposure to the virus. Meaning, if you were in contact with someone who tested positive, change and wash your clothes. However, if you’ve been mostly outdoors and have maintained social distancing, then it’s unlikely your clothes have been contaminated.

Regarding the COVID-19 vaccines, here’s what public health officials and infectious diseases experts are saying in a nutshell: While COVID-19 vaccines are extraordinarily effective at preventing symptomatic disease, they are not foolproof. No vaccine can guarantee 100% protection of fully vaccinated people with zero breakthrough cases. Some people will still get sick or even need to be hospitalized, but you are unlikely to become a breakthrough case if you continue to be sensible about taking precautions.


  1. https://feeds.aarp.org/health/conditions-treatments/info-2021/coronavirus-after-vaccination.html?_amp=true
  2. https://www.prevention.com/health/amp36122067/can-you-get-covid-19-after-vaccine/
  3. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/effectiveness/why-measure-effectiveness/breakthrough-cases.html
  4. https://www.forbes.com/sites/brucelee/2020/05/01/how-long-does-covid-19-coronavirus-survive-on-clothes-how-to-wash-them/?sh=6beb912164e6