If you have had COVID-19, you may wonder if you need to get a COVID-19 vaccine. People infected with COVID-19 produce antibodies that offer protection (“natural immunity”) from future exposures. However, not everyone builds the same immune response, and research is not yet clear on how strong, or for how long, protection from natural immunity lasts. What is clear is that immunity wanes over time, and vaccinations after infection offer improved protection.
COVID-19 infection provides more protection when combined with vaccine immunity
Research in Kentucky comparing individuals who had COVID-19, found that those who did not get vaccinated were more than two times as likely to be re-infected than those were fully vaccinated.
Research also suggests people who experienced mild or asymptomatic cases of COVID-19 may not have built as many antibodies as someone who had a more severe case. For example, this study found a “striking” difference between the antibody responses and neutralization of hospitalized patients compared to outpatients.
Natural immunity wanes over time
Because people build a wide range of antibodies, it is difficult to know the defense someone has after an infection. What we do know is that antibodies, whether built from vaccination or a previous infection, decrease over time. A study of 156 health care workers who experienced mild cases of COVID-19 found that:
- 94% of participants had fewer antibodies after about two months, and
- 28% no longer had enough antibodies to meet the threshold to test positive.
This means the more time that passes after infection, the more vulnerable one is to becoming ill with COVID-19.
Vaccine immunity is the safest choice for building COVID-19 protection
The only ways to build those antibodies back up is through a vaccine, or to become infected again. Becoming infected with COVID-19 risks hospitalization, damage to your lungs, heart, kidneys and brain, or death from a disease that has now killed 1 of every 463 Americans since January, 2020. Even mild cases can result in “long-haulers” who have symptoms for months.
If you have recovered from COVID-19 or were asymptomatic, then vaccination is still the best choice. The CDC recommends if you were treated for COVID-19 with monoclonal antibodies or convalescent plasma to wait 90 days before receiving a COVID-19 vaccine.
COVID-19 vaccines are safe, effective and available near you
Vaccines are safe and the most effective way to protect us against serious illness, hospitalization and death due to COVID-19. Find a vaccine site near you at Get Vaccinated Oregon (GVO).