If You Got This Vaccine, You May Have More Antibodies, New Study Says
Researchers found this shot created a very robust immune response
The COVID-19 vaccines available in the U.S. are highly effective because they trigger an immune response to produce antibodies that can protect against the virus. Of course, each vaccine is made differently, meaning that each can have a different effect on the body, work differently against new variants, and offer different levels of protection over time. But a new study has found that one current vaccine in particular may produce considerably more antibodies than the others.
The findings come from a study published on August 16 in JAMA Internal Medicine, which analyzed the vaccine response in 954 healthcare workers from the Johns Hopkins Health System. Results found that those who received the Moderna mRNA vaccine developed more spike IgG antibodies than those who received the Pfizer vaccine 14 or more days after their second dose.
The authors also found that on top of a robust antibody response, participants who received the Moderna vaccine were significantly more likely to report "clinically significant symptoms," which the study authors defined as fatigue, fever, and chills. Results showed that while only 43 percent reported any kind of symptoms at all after their second dose, those who received Moderna were 83 percent more likely to report clinically significant symptoms after their first dose than Pfizer recipients and 150 more likely after the second dose.
The study's authors concluded that there might be a correlation between the increased likelihood of symptoms and the increased antibodies seen in recipients of the Moderna vaccine. But they cautioned that having recovered from COVID-19 might affect results and causing some to be concerned their shots may not have taken hold with their immune system.
"These vaccines can elicit greater local and systemic reactions in persons with prior SARS-CoV-2 infection," they wrote. "Whether symptoms following vaccination are associated with effectiveness is unknown, and, therefore, anxiety can arise in persons who did not develop a reaction following vaccination."
Regardless, the study authors concluded that the Moderna vaccine was more likely to produce a stronger immune response and more antibodies. "Spike IgG antibody measurements were higher in healthcare workers who received the Moderna vaccine, had prior SARS-CoV-2 infection, and reported clinically significant reactions," the study's authors wrote. "The role of higher antibody levels in preventing COVID-19 and providing lasting immunity remains unknown, however. Overall, the findings suggest that regardless of vaccine reactions or prior SARS-CoV-2 infection, either spike mRNA vaccine will provide a robust spike antibody response."
Other recent research has begun to give scientists a better understanding of exactly how antibodies can help determine how protected someone is from the novel coronavirus. During a press briefing held by the White House COVID response team on Aug. 18, Anthony Fauci, MD, chief White House COVID adviser, cited a study released on a preprint server on Aug. 10. He explained that researchers were looking for "correlates of immunity" in the bloodstream of vaccinated people and found specific proteins that can neutralize the virus.
The study concluded that higher levels of these antibodies in patients signified higher vaccine efficacy. The findings underscored Fauci's argument that the general public would need booster shots to raise antibody levels to protect against highly contagious variants such as Delta, NPR reported.