Getting Vaccinated After Having COVID-19: What to Know
If you’ve already had COVID-19, do you really need to get vaccinated? After all, your body has been exposed to the virus. Hasn’t your immune system cranked out antibodies that will protect you from future infection?
The answer is complex: Yes, your body likely has created COVID-19 antibodies; and no, those antibodies might not be sufficient to protect you. That’s why health experts recommend vaccination for everyone eligible to receive a vaccine, regardless of whether you’ve had COVID-19.
Because COVID-19 is still a relatively new disease, no one yet knows how long COVID-19 antibodies will protect you from illness or what level of antibodies are necessary to create an effective defense and how (or if) those levels decline over time. Researchers are currently working hard to learn more about the body’s reaction to COVID-19 and how long natural immunity persists after illness. Recent evidence offers hope that natural immunity may last for years. Antibodies (proteins) specific to the virus that circulate in the blood decrease over time, but immune cells that "remember" the virus are present six months after infection. Another study finds that the bone marrow of recovered patients retains virus-specific cells for at least 11 months following infection. These cells are capable of providing long-lived immunity to the virus. These studies were done on a small number of patients; some had been hospitalized, but most had a mild course of disease.
The strength of immunity to the virus likely varies between people and between variants or strains of the virus. What researchers and scientists know is that COVID-19 continues to be a serious threat to individuals and public health. There have been reports of COVID-19 reinfection, which indicate that it’s possible for a person to get COVID-19 again after having it once.
COVID vaccination can keep you from getting seriously ill if you contract COVID-19 again. It can also decrease the spread of the virus throughout the population, which is key to resuming public activities, such as concerts and large gatherings.
Researchers also know that the vaccine is safe—and highly effective—in people who have had COVID-19. A study of 1,000 people found that those who previously had COVID-19 had much higher antibody levels after just one dose of mRNA COVID-19 vaccine (Moderna or Pfizer-BioNTech) than those with no history of infection. Those levels likely went even higher after participants received their second vaccine dose.
You can get a COVID-19 vaccine as soon as you have recovered and are no longer in quarantine—unless you received monoclonal antibodies or convalescent plasma as a treatment. (Not sure? Check with your doctor.) Individuals who were treated with monoclonal antibodies or convalescent plasma should wait 90 days from treatment before getting vaccinated.
Why? Because the treatment may interfere with your body’s response to the vaccine. Waiting 90 days gives your immune system the best chance of generating antibodies after vaccination.
Those who are experiencing “long-haul COVID,” or continued health problems after COVID infection, should get vaccinated as soon as possible. Some people with long COVID have reported improvement of their symptoms after COVID-19 vaccination.
If you’ve had COVID-19, you may experience more intense side effects to vaccination than vaccinated people who were not previously infected. Why? Because your body has already been exposed to SARS-CoV-2 (the virus that causes COVID-19), your immune system may jump into action more intensely than if you had not been infected before.
You might also experience side effects after the first dose of your vaccine, rather than after the second dose more typical of people who have no history of infection. COVID-19 vaccine side effects may include fatigue, fever, chills, and muscle pain or achiness. According to at least one research study (and many anecdotal reports), many people who were previously infected with the virus reported these flu-like symptoms after their first COVID-19 vaccine dose.
Other commonly reported vaccine side effects (regardless of prior infection) include redness, swelling, and pain at the injection site (in some cases, the pain is intense enough that it limits motion for a day or so), nausea, and headaches. Some women also experience swelling of the lymph nodes in the neck and armpit area. (The Society of Breast Imaging advises women to wait 4 to 6 weeks after vaccination before undergoing a screening mammogram to decrease the likelihood that swollen glands might be interpreted as possible cancer.)
If you are receiving a COVID-19 vaccine that requires two doses (as both the Moderna and Pfizer-BioNTech vaccines do), you may also experience side effects after your second dose. People who have been vaccinated recommend scheduling your vaccine before some time off, if possible, so you can nap and recoup if necessary. You can take acetaminophen (Tylenol) after vaccination if you feel poorly.
Concerned about side effects? Remember that the side effects of vaccination typically clear up in a day or two; COVID-19 can be deadly.
Your healthcare provider or local health department can help you understand the risks and benefits of COVID-19 vaccination, so you can make an informed decision.