Moderna said Monday that its two-dose COVID-19 vaccine generates a weaker immune response against a worrisome strain of the disease that first emerged in South Africa, prompting the firm to plan a clinical trial in the United States of a “booster” shot that recipients would receive.
The Cambridge biotech said the South African variant caused a six-fold reduction in neutralizing antibodies generated by the vaccine cleared last month for emergency use by the Food and Drug Administration, based on a new Moderna study. While that’s a dramatic decrease, the company said those antibody levels are still enough to protect people against the South African strain.
Advertisement
Nonetheless, “out of an abundance of caution,” Moderna will test a booster shot on laboratory animals and then people “to determine if it will be more effective” against the South African strain and potentially other variants, according to Moderna chief executive Stephane Bancel. He gave no timetable for the clinical trial.
The South African variant has been detected outside that country but not in the United States as of Saturday, according to National Institutes of Health Director Francis Collins and Dr. Anthony Fauci, President Joe Biden’s top coronavirus medical adviser. The strain has 10 mutations located on the spike protein that the coronavirus uses to invade cells and has been a key target of vaccine designers.
Moderna’s study found that another coronavirus variant that first emerged in the United Kingdom had no significant impact on the level of neutralizing antibodies produced by the two-dose vaccine. That strain, which has eight mutations on the spike protein, has been detected in numerous countries, including the United States and in Massachusetts.
Researchers exposed the two strains to blood samples taken from eight people who were vaccinated in the firm’s early-stage trial.
The company’s study was conducted with help from the federal government and is expected to be published on a preprint server soon. It has not been submitted to a peer-reviewed publication.
Advertisement
This is a developing story that will be expanded.
Jonathan Saltzman can be reached at jonathan.saltzman@globe.com.
January 25, 2021 at 08:31PM
https://ift.tt/2MiKGAq
Moderna plans study of a COVID-19 booster shot to combat variants - The Boston Globe
https://ift.tt/2DVP6sH
No comments:
Post a Comment