If you have already been infected with COVID-19, you may be wondering if you need to be vaccinated against the virus. The short answer is yes! Here’s what you need to know.
The World Health Organization and the US Centers for Disease Control and Prevention both said the vaccine can be offered to you regardless of whether you have ever had a COVID-19 infection. The CDC says it made this decision based on the convincing amount of evidence that it is possible to be infected again with the disease.
“We do not know how long it will protect against infection and many of the people being vaccinated do not know whether they have been infected due to the high rates of asymptomatic transmission,” Professor Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and co-director from the Texas Children’s Hospital Vaccine Development Center, he told IFLScience.
A good deal of evidence has shown that it is possible to be infected with COVID-19 twice. At the moment, however, there are still many things about COVID-19 reinfection that we don’t know about. One of the main questions is how long antibodies to an infection last. Some studies have suggested that antibodies to Covid-19 can disappear within two to three months, while others even suggested mild infections can trigger long-term immunity since there is some evidence of memory T cell responses. In all likelihood, immune memory tends to differ between people and the severity of the disease, with more severe cases likely triggering a stronger immune response.
“Our data show that 90 percent of people previously infected with SARS-CoV-2 have lasting immunity – the immune response is there and remains. But it also means that 10 percent of COVID-19 survivors have weak immune memory and may be vulnerable to a case of recurrent COVID-19 infection in the future, or they may be more likely to infect others. ” explained Dr. Alessandro Sette, professor at the La Jolla Institute of Allergy and Immunology, also speaking to IFLScience.
“Unfortunately, we currently don’t have an easy way to measure different types of memory T and B cells in conjunction with antibodies,” added Sette. “But even if we knew the levels of antibodies and T cells, we don’t have enough information to determine how much is sufficient to protect individuals from infections and / or serious illnesses, and therefore the standard decision would be to be vaccinated.”
Granted, it is also unclear how long vaccines can end up protecting you, as the tests were not long enough to show this definitively, although the data so far is promising. it is It was determined that the protection of the Pfizer vaccine does not decrease for at least two months, while the Moderna vaccine produces potent antibodies that last at least three months. Immunity is believed to last longer than that, but the data is not yet available.
“Vaccination is likely to also increase the levels of immunity acquired by natural immunity,” notes Dr. Sette.
There is also no evidence that having the vaccine is risky for people who have already received COVID-19. Clinical trials for the Pfizer and Moderna vaccines have not actively recruited people who have already contracted the disease, but it is believed that until 10 percent of participants had the virus due to the presence of certain neutralizing antibodies. Like everyone else in the study, the vaccine proved to be generally safe, with very limited side effects. However, the CDC suggests that people should wait at least 90 days after infection with COVID-19 “as a precautionary measure until additional information is available.”
Unfortunately, not everyone will instantly have the opportunity to be vaccinated against COVID-19. It can be argued that those with a previous infection are at lower risk and should be placed at the end of the line and not prioritized. As such, the WHO suggested that individuals may wish to postpone their own vaccination for up to 6 months “due to limited vaccine supply.” While this makes sense in theory, it is likely to be a choice left to the individual and not enshrined in any rules.
“As for prioritization, we don’t have a system for operationalizing those with a previous infection, so for the time being it’s probably not a criterion. And at least half with a previous infection don’t know that, ”adds Hotez.
For more information on COVID-19, check out the IFLScience COVID-19 hub, where you can track the current status of the pandemic, the progress of vaccine development and more information about the disease.