Moderna’s vaccine against Covid-19 generated antibodies that persisted for 90 days after inoculation, good news while its authorization in several countries is being studied, indicated a study carried out in 34 participants since the beginning of clinical trials, published on November 3rd, in the New England Journal of Medicine.
The duration of protection is undoubtedly longer, but these are the first data in a period of several months validated independently by a scientific journal.
Participants will be followed for 13 months to check long-term immunity, say the authors.
Researchers at the National Institutes of Health assessed the level of two types of antibodies against the coronavirus 90 days after the second dose of the vaccine, which in turn was administered 28 days after the first.
They observed a “slight” and expected decrease in the level of antibodies in vaccinated participants, but to a degree that remained high and above the natural immunity revealed in patients who were infected with Covid-19 and recovered.
In addition, no serious side effects were seen in the so-called phase 1 trial, which began in March.
Antibodies are just one component of the immune response, along with B lymphocytes (immune memory, antibody production) and T lymphocytes (which kill infected cells).
The researchers note that data on immune memory cells is not yet known.
Anthony Fauci, director of the Infectious Diseases Institute, recently told AFP that he was “sure” that the immune memory created by the vaccine would last for some time.
“We don’t know if it will be one, two, three or five years, we don’t know,” he said. Only time can tell.
“This is very positive news in general,” added Benjamin Neuman, a professor at Texas A&M University, on Thursday to AFP, referring to the new study, noting that even in the elderly the immune response remained “reasonably strong”.