MIAMI – Scientists in the U.S. are preparing a booster-shot program. It will start by giving further doses of the COVID vaccine to at-risk groups. The first in line will be people who have already been fully vaccinated, but they still need to elevate the levels of antibodies to elicit a strong immune response.
Research shows some people did not generate high levels of antibodies after the two doses of the vaccine and they need booster immunization. Among them are blood cancer patients and organ-transplant recipients who are taking immunosuppressive drugs.
“That doesn’t allow their bodies to make that same quality of antibodies,” said Aileen Marty, an infectious disease expert at Florida International University.
Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said “many of them, maybe most of them, have not gotten an adequate immune response, to begin with.”
Although the highly contagious Delta variant is surging in Florida, the deployment of boosters won’t start any time soon. Epidemiologists don’t want to divert much-needed doses away from other countries in need. The World Health Organization called for a moratorium on boosters after Israel, China, and other countries started to administer extra shots.
Moderna and Pfizer–BioNTech have continued to push for third doses, but there are still a lot of variables that scientists are trying to understand about the effectiveness of the vaccines. The antibody levels COVID-19 vaccines triggered fall over time, but scientists don’t know with certainty if this means the inoculated subjects are less protected over time.
The U.S. Centers for Disease Control and Prevention has referred to the Delta variant’s rare infections of vaccinated people as vaccine “breakthrough” cases, but scientists believe the vaccines still offer protection against severe disease and hospitalization.
There is also the issue of whether or not the Moderna and Pfizer-BioNTech vaccines can be mixed and matched. Marty said studies in other countries have shown positive results.