20 December 2021
American drugmaker Moderna said Monday that a third dose of its COVID-19 vaccine should protect against the Omicron version of the new coronavirus.
Moderna said laboratory tests showed its half-dose booster shot increased the level of antibodies able to fight Omicron by 37 times. A full-dose booster had an even stronger effect. The company said it gave 83 times the antibody levels. Half-dose shots are being used for most Moderna boosters. But a full-dose third shot has been advised for people with weakened immune systems.
Moderna's early results have not yet been carefully examined by other scientists. But testing by the U.S. National Institutes of Health found a similar increase in antibody levels.
Another American company, Pfizer, said testing found its COVID-19 vaccine led to a big increase in Omicron-fighting antibodies. Pfizer and its German partner BioNTech said this month that early lab tests showed its full-strength booster increased levels of antibodies by "25-fold."
The vaccines made by Pfizer and by Moderna are both made with messenger RNA technology. The shots are used by many countries around the world to fight the pandemic. Health officials are advising people to get booster injections as soon as possible.
Antibody levels predict how well a vaccine may prevent infection with the coronavirus. However, they are just one part of the immune system's defenses. Other research suggests the vaccine should offer good protection against severe disease. This should be the case even if a fully vaccinated person gets what is known as a breakthrough infection.
Both Moderna and Pfizer are developing shots to better deal with the Omicron variant in case they are needed. Pfizer also recently said its experimental pill to treat COVID-19 appears to work well against the Omicron version.
Omicron was first found in southern Africa on November 9 and reported to the World Health Organization (WHO) on November 24. Two days later, the WHO designated it a variant of concern.
I'm Ashley Thompson.
The Associated Press reported this story. Ashley Thompson adapted it for VOA Learning English. Mario Ritter, Jr. was the editor.
Words in This Story
dose – n. the amount of a medicine, drug or vitamin that is taken at one time
booster –n. an additional amount of something that strengthens an earlier treatment, such as a vaccination
immune system –n. the system that protects the body from disease and infections
-fold –suffix times the amount it is attached to
variant – n. something that is different in some way from others of the same kind