Novavax COVID-19 vaccine works, but less so
By Lauran Neergaard
The Associated Press
January 28, 2021
Novavax Inc. said Thursday that its COVID-19 vaccine appears
89% effective based on early findings from a British study and
that it also seems to work — though not as well — against new
mutated versions of the virus circulating in that country and
The announcement comes amid worry about whether a variety of
vaccines being rolled out around the world will be strong enough
to protect against worrisome new variants — and as the world
desperately needs new types of shots to boost scarce supplies.
The study of 15,000 people in Britain is still underway. But
an interim analysis found 62 participants so far have been
diagnosed with COVID-19 — only six of them in the group that got
vaccine and the rest who received dummy shots.
The infections occurred at a time when Britain was
experiencing a jump in COVID-19 caused by a more contagious
variant. A preliminary analysis found over half of the trial
participants who became infected had the mutated version. The
numbers are very small, but Novavax said they suggest the
vaccine is nearly 96% effective against the older coronavirus
and nearly 86% effective against the new variant. The findings
are based on cases that occurred at least a week after the
"Both those numbers are dramatic demonstrations of the
ability of our vaccine to develop a very potent immune
response," Novavax CEO Stanley Erck said in a call with
investors late Thursday.
Scientists have been even more worried about a variant first
discovered in South Africa that carries different mutations.
Results from a smaller Novavax study in that country suggests
the vaccine does work but not nearly as well as it does against
the variant from Britain.
The South African study included some volunteers with HIV.
Among the HIV-negative volunteers, the vaccine appears 60%
effective. Including volunteers with HIV, overall the protection
was 49%, the company said. While genetic testing still is
underway, so far about 90% of the COVID-19 illnesses found in
the South African study appear due to the new mutant.
"These are good results. There is reason to be optimistic"
about the 60% effectiveness, said Glenda Gray, head of the South
African Medical Research Council. Even against the new variant
that now causes more than 90% of new cases in that country,
"we’re still seeing vaccine efficacy," she said.
More concerning is what the study showed about a totally
different question — the chances of people getting COVID-19 a
second time, said the leader of the South African study, Shabir
Madhi of the University of the Witwatersrand in Johannesburg.
Tests suggested that nearly a third of study participants had
been previously infected, yet rates of new infections in the
placebo group were similar.
"Past infection with early variants of the virus in South
Africa does not protect" against infection with the new one, he
said. "There doesn’t seem to be any protection derived."
Novavax said it needs some additional data before it can seek
British authorization for the vaccine’s use, sometime in the
next month or so. A larger study in the U.S. and Mexico has
enrolled slightly over half of the needed 30,000 volunteers.
Novavax said it’s not clear if the Food and Drug Administration
will need data from that study, too, before deciding whether to
allow U.S. use.
Meanwhile, it is starting to develop a version of the vaccine
that could more specifically target the mutations found in South
Africa, in case health authorities eventually decide that
updated dosing is needed.
Vaccines against COVID-19 train the body to recognize the new
coronavirus, mostly the spike protein that coats it. But the
Novavax candidate is made differently than the first shots being
used. Called a recombinant protein vaccine, the Maryland company
uses genetic engineering to grow harmless copies of the
coronavirus spike protein in insect cells. Scientists extract
and purify the protein and then mix in an immune-boosting
AP Medical Writer Marilynn Marchione
The Associated Press Health and Science
Department receives support from the Howard Hughes Medical
Institute’s Department of Science Education. The AP is solely
responsible for all content.