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* South Africa puts AstraZeneca vaccinations on hold
* Study: shot gives minimal protection against mild
infection
* Britain says Astra shot stops death and severe illness
* Concerns rise over longer fight against virus
(Adds details of study)
By Guy Faulconbridge and Kate Holton
LONDON, Feb 8 (Reuters) - South Africa halted Monday's
planned rollout of AstraZeneca's COVID-19 vaccinations after
data showed it gave minimal protection against mild infection
from one variant, stoking fears of a much longer cat-and-mouse
battle with the pathogen.
The coronavirus has killed 2.3 million people and turned
normal life upside down for billions but new variants have
raised fears that vaccines will need to be tweaked and people
may have to have booster shots.
Researchers from the University of Witwatersrand and the
University of Oxford said in a prior-to-peer analysis that the
AstraZeneca vaccine provided minimal protection against mild or
moderate infection from the so-called South African variant
among young people.
"This study confirms that the pandemic coronavirus will find
ways to continue to spread in vaccinated populations, as
expected," said Andrew Pollard, chief investigator on the Oxford
vaccine trial.
"But, taken with the promising results from other studies in
South Africa using a similar viral vector, vaccines may continue
to ease the toll on health care systems by preventing severe
disease."
South African Health Minister Zweli Mkhize said on Sunday
the rollout would be put on hold and that the government would
await advice from scientists on how best to proceed.
The AstraZeneca vaccine was the big hope for Africa as it is
cheap and easier to store and transport than the Pfizer shot,
making South Africa's move a major blow, with implications for
other regions.
An analysis of infections by the South African variant
showed there was only a 22% lower risk of developing
mild-to-moderate COVID-19 versus those given a placebo.
If vaccines do not work as effectively as hoped against new
and emerging variants, then the world could be facing a much
longer and more expensive battle than previously thought.
Protection against moderate-severe disease, hospitalisation
or death could not be assessed in the study as the target
population were at such low risk, the researchers said.
While thousands of individual changes have arisen as the
virus mutates on replication and evolves into new variants, only
a tiny minority are likely to be important or change the virus
in an appreciable way, according to the British Medical Journal.
VACCINE SHOCK
While the lead investigator on the trial said that recent
data indicated that protection against severe disease was likely
from the vaccine, the study raised the prospect of repeated
vaccination against a changing virus.
Professor Shabir Madhi, lead investigator on the AstraZeneca
trial in South Africa, said the vaccine's similarity to another
produced by Johnson & Johnson, which reduced severe disease by
89%, suggested it would still prevent serious illness or death.
"There's still some hope that the AstraZeneca vaccine might
well perform as well as the Johnson & Johnson vaccine in a
different age group demographic that I address of severe
disease," he told BBC radio.
Sarah Gilbert, professor of vaccinology at the University of
Oxford, said efforts were under way to develop a new generation
of booster shot vaccines that will allow protection against
emerging variants.
"This is the same issue that is faced by all of the vaccine
developers, and we will continue to monitor the emergence of new
variants that arise in readiness for a future strain change,"
she said.
UK IS 'CONFIDENT'
The AstraZeneca vaccine prevents death and serious illness
and is effective against the main variants of the virus in the
United Kingdom, though people may have to have a booster shot as
it mutates, a junior health minister said on Monday.
"There is no evidence that this vaccine is not effective in
preventing hospitalisation and severe illness and death, which
ultimately is what we're seeking with these vaccines today,"
junior health minister Edward Argar told Sky.
"The dominant strains in this country are not the South
African strain, there are a small number of cases of that, the
dominant strains here are the historic one we've had, and then
the Kent variant, against which this vaccine is highly
effective."
Argar said just 147 people had been known to have been
infected with the South African variant in Britain, though he
allowed that booster shots - such as against the common flu -
might be needed in future.
"It would just be normal, in a sense, as we did with the flu
vaccine, to update it to catch anything the virus is trying to
do to keep ahead of it."
(Reporting by Guy Faulconbridge and Kate Holton; editing by
Michael Holden, Angus MacSwan and Nick Macfie)
