The COVID-19 pandemic continues to propagate because the coronavirus spike protein evolves, which helps the virus infiltrate a host cell and new variants emerge that help the infection spread more easily from person-to-person.
As a result, antibodies that a person developed after an early infection or after vaccination may not adequately protect the body from these newer emerging variants.
An area of the spike protein called the receptor binding domain, or RBD enables the virus to invade a host cell. This region is also a critical target for antibodies, but random mutations in the RBD make it an ever-changing target.
In the new study, researchers compared anti-RBD antibodies in the blood of participants to the ability of the antibodies to neutralize the virus.
In uninfected patients who had received 1 of 2 COVID-19 vaccines, researchers found antibodies that were less effective against mutations in the new variants (like Beta or Gamma) than they were against the original genetic sequence encoded in the vaccine.
Similarly, when they analyzed blood samples from people infected with the COVID-19 before May 2020 had reduced potency against newer variants compared to the original.
These findings suggest that both mild infection and vaccination produce antibodies that still leave a person vulnerable to new variants.
However, in prior-infected and vaccinated individuals, researchers found that antibodies were unchanged in efficacy against the original sequence but just as potent against new variants.
These findings also align with similar findings by other groups, published earlier this year, and also show that high-quality antibodies are produced in people who had been infected and vaccinated.
They also help researchers to improve the implementation of vaccines and boosters not only for COVID-19 but also for the next pathogen that comes along.
Source: Medindia
