A single dose of the
Moderna coronavirus
vaccine given as a booster rapidly increased the level of antibodies
in people who had already been vaccinated, the company announced on Wednesday.
اضافة اعلان
The antibodies produced by the booster
were effective against the original form of the virus, as well as against the
variants of concern first identified in South Africa and Brazil. A second
booster specifically designed to counter B.1.351, the variant identified in
South Africa, produced an even stronger immune response against that variant.
The results are from an early stage of
Moderna’s trial of the boosters and have not yet been published or vetted by
other scientists. Moderna plans to post the findings to the preprint server
bioRxiv, the company said on Wednesday.
“We are encouraged by these new data,
which reinforce our confidence that our booster strategy should be protective
against these newly detected variants,” Stéphane Bancel, Moderna’s chief
executive officer, said in a statement.
The boosters, tested in 40
participants, were administered as a third shot six to eight months after the
two-shot immunization with the current vaccine. Antibodies from the initial
vaccination were detectable in 37 of those people, but in about half the
participants, the antibodies performed poorly against the variants that have
pummeled South Africa and Brazil. The boosters raised the levels of the
antibodies against both variants, although the boosters were still slightly
less effective than against the original form of the virus.
The mRNA platform used in the Pfizer
and Moderna vaccines can be readily tweaked, enabling the companies to produce
newer versions within weeks. Moderna began modifying its vaccine to combat the
variant identified in South Africa, after reports emerged that the existing
vaccines are slightly less effective against that variant. The variant carries
a mutation that helps the virus sidestep the immune system.
Moderna is testing three strategies
for enhancing the immunity produced by the current vaccine: using the current
vaccine as a booster; using the booster designed specifically to combat
B.1.351; and a combination of the two in a single vaccine.
Wednesday’s announcement refers to
results achieved two weeks after immunization with either a booster of the
original vaccine or of the booster modified for B.1.351. The company plans to
release data from later time points, and from tests of the combination booster,
as they become available.
Read more
Health
.jpg)
.jpg)
