A new study conducted by scientists from the National Institutes of Health (NIH) and Moderna Inc. showed that mRNA vaccines hurt the long-term immunity to Covid-19 after contracting infection compared to unvaccinated people.
Researchers performed a placebo-controlled vaccine efficacy trial published at medRxiv last month, to evaluate anti-nucleocapsid antibody (anti-N Ab) seropositivity in Moderna vaccine efficacy after Covid-19 infection.
“To evaluate for evidence of prior infection in a person with a history of COVID-19 vaccination, a test that specifically evaluates anti-N should be used. Past infection is best determined by serologic testing that indicates the presence of anti-N antibody,” according to the CDC.
The study analyzed data from 1,789 participants (1,298 placebo recipients and 491 vaccine recipients) with Covid-19 infection at 99 sites in the US during the blinded phase (through March 2021).
The study concludes that anti-nucleocapsid antibody (anti-N Abs) may have lower sensitivity in patients vaccinated with Moderna who become infected. The study also mentioned that the anti-N Ab response in unvaccinated persons has been reported to be durable, with half-life estimates ranging from 68 to 283 days.
Among the participants with confirmed Covid-19 illness, only 21 out of 52 (40%) of people who received the Moderna shots had antibodies compared to the placebo recipients, 605 out 648 (93%).