Moderna’s Covid-19 vaccine candidate produced a robust immune response in all 45 individuals who participated in an early-stage human trial, raising hopes that the vaccine may offer some protection against the coronavirus, according to a preliminary report published in The New England Journal of Medicine.
- The antibody levels observed in all 45 participants were on the upper half of what has been seen in patients who’ve recovered from the disease.
- The antibody response does not prove that the vaccine will be effective but it fulfills an important first goal of the test.
- The 15 participants who received the highest dose of the vaccine displayed antibody levels that were four times higher than the recovered patients.
- While the vaccines did not show serious toxicity, more than half of the participants experienced mild side effects including moderate fatigue, chills, headaches, and muscle pain.
- Three of the patients who received the highest dose of the vaccines experienced severe side effects, the report notes, without elaborating further.
- Moderna has stated that the high 250 microgram dosage will not carry forward to its expanded trial, which will enroll 30,000 participants.
- Evaluation of the durability of immune responses is ongoing, Moderna said in a press release, adding that participants will be followed for one year after the second vaccination.
Moderna’s stock is up 9.8% in after-hours trading following the publication of the results.
Moderna is testing a vaccine that contains genetic material called messenger RNA that causes cells to produce the Covid-19 spike protein and induces an immune response from the body. It differs from a traditional vaccine, where a person is injected with a weakened or inactivated version of the virus itself. The published findings are in line with results Moderna had published in a press release in May, but they provide more details on antibody levels and side-effects. Last month, the country’s top infectious disease official, Dr. Anthony Fauci, had told the U.S. Congress that he’s “cautiously optimistic” scientists will be able to create at least one safe and effective vaccine by the end of the year or early 2021.