Last checked at 
* Laboratory study published on Pfizer vaccine
* Suggests reduced protection vs local virus variant
* South Africa expecting 7 mln Pfizer doses by June
* AstraZeneca jabs already on hold over trial data
* Country worst-affected by pandemic on continent
(Adds WHO immunisation official, context)
By Alexander Winning and Wendell Roelf
JOHANNESBURG, Feb 18 (Reuters) - Scientists will meet on
Thursday to advise South Africa's government on its next steps
after a study suggested the dominant local coronavirus variant
may reduce antibody protection from Pfizer's COVID-19 vaccine by
two-thirds.
The laboratory study, published in the New England Journal
of Medicine, dealt a new blow to the country hardest-hit by the
pandemic on the African continent.
The government and its advisers must weigh whether to wait
for vaccines that might be more effective against the more
infectious 501Y.V2 variant, or try to vaccinate people quickly
to avert further infections and deaths.
South Africa had been counting on the Pfizer shot,
developed with German partner BioNTech, to step up
its vaccination programme after administering the first Johnson
& Johnson (J&J) doses on Wednesday.
Earlier this month, it placed AstraZeneca
vaccinations on hold because of interim data showing its jab
offered minimal protection against mild to moderate illness from
the 501Y.V2 variant first identified late last year.
Officials are more confident about the J&J shot because it
was shown to be effective in preventing severe illness in the
local leg of a large global trial.
The detailed laboratory study published on Wednesday took
into account all key mutations of the 501Y.V2 variant. A paper
published in late January assessed the impact of only three key
mutations of the variant on the Pfizer vaccine.
Scientists said that because the new study's findings come
from a laboratory, it is not easy to extrapolate what they might
mean for the shot's efficacy in the real world.
"Our scientists will be meeting to discuss it (the study)
and they will advise the minister," health ministry spokesman
Popo Maja said.
Barry Schoub, a professor and chair of the Ministerial
Advisory Committee on vaccines, said the committee would discuss
the study alongside information on other COVID-19 vaccines.
Asked to comment on the findings, he said: "The Pfizer
vaccine is enormously effective at 95%, so even if there is
quite a significant reduction there still will be quite a bit of
remnant efficacy left."
"It is very likely that it will protect to a reasonable
extent, certainly against severe illness and mild to moderate to
some extent," he said.
"STRONG ENOUGH"
Richard Mihigo, an immunisation official at the World Health
Organization's Africa office, told a news conference the
antibody response to the variant in the Pfizer study was "strong
enough".
Linda-Gail Bekker, co-lead investigator of the South African
arm of J&J's global trial, said she would recommend rolling out
the Pfizer vaccine but monitoring it in the same way as the J&J
shot, which is being administered in an "implementation study"
targeting up to 500,000 health workers to further test it in the
field.
"We should make sure we do see the effectiveness we (are)
hoping for," she told Reuters.
Health Minister Zweli Mkhize said on Wednesday South Africa
was expecting 500,000 doses of the Pfizer vaccine initially and
about 7 million doses by June.
A spokesman for regulator SAHPRA said Pfizer's registration
application was under review and declined further comment.
South Africa, with nearly 1.5 million cases and about 48,500
deaths, has recorded almost half the COVID-19 fatalities and
over a third of confirmed infections in Africa. It lagged richer
Western nations in launching its immunisation campaign.
The government plans to vaccinate 40 million people -
two-thirds of the population.
"Luckily there are a range of vaccines available and what we
will do is work with the national authorities to understand the
implications of this (study) and see what they need to do," the
WHO's Africa director, Matshidiso Moeti, said.
(Reporting by Alexander Winning in Johannesburg and Wendell
Roelf in Cape Town; Additional reporting by Kate Kelland in
London, Ludwig Burger in Frankfurt and Aaron Ross in Dakar;
Editing by Olivia Kumwenda-Mtambo, Angus MacSwan, Raju
Gopalakrishnan and Timothy Heritage)
