Sinopharm vaccine in UAE: how effective is it against Covid-19 and are there side effects?
In recent weeks we've learned much more about the vaccine's efficacy, ability to fight new strains and how long protection lasts for
The UAE has now administered more than 7.5 million coronavirus vaccine doses.
Most of these have been the Sinopharm vaccine, produced by the Chinese pharmaceutical company’s Beijing unit.
Unlike vaccine manufacturers in the West, Sinopharm Group has yet to release Phase 3 trial data in a published medical journal.
But authorities in the UAE have publicly shared information about its effects since mass vaccination began in December.
So how effective is it? How long does the protection last?
And how does it compare with other vaccines?
The National explains.
Is the Sinopharm vaccine effective against Covid-19?
Tests in the UAE suggested the vaccine was 86 per cent effective against preventing infection in Phase 3 trials involving 31,000 people. The manufacturer revised the figure to 79.34 per cent after it received more data.
Doctors say the key metric is whether it stops people getting seriously ill.
There is still no evidence of anyone developing serious disease after the vaccine.
Dr Nawal Al Kaabi, chairwoman of the National Covid-19 Clinical Management Committee, said there were no critical care admissions or deaths among those who had been vaccinated in Abu Dhabi, making it 100 per cent effective against serious disease.
People who were infected after taking both doses of the vaccine mostly remained asymptomatic or presented only mild symptoms, she said.
Although the Pfizer-BioNTech vaccine has proven extremely effective, it has not been shown to prevent serious disease completely.
In Israel, the Pfizer-BioNTech vaccine was found to be 87 per cent effective at preventing conditions requiring hospital treatment and 92 per cent effective at preventing severe disease after two doses.
It is 72 per cent effective at preventing death 14 to 20 days after the first dose, officials said.
How effective is Sinopharm against new strains?
This is the big question.
A February study suggested the Sinopharm vaccine is less effective against the South African variant, but it still works.
Researchers tested a blood sample from a patient who received the vaccine against that strain.
It is one of the most worrying variants, because it is more contagious and includes a mutation that helps it evade neutralising antibody responses of people who were infected with the original virus.
It shares this mutation with the variant from Brazil.
The Sinopharm vaccine resulted in a 1.6-fold reduction in antibodies against the variant, largely preserving the neutralisation of it.
This means the variant does not escape the immunity induced by the vaccine, researchers said.
Can Sinopharm be adapted to fight the new variants?
Yes. Speaking on Chinese television, Wang Hui, general manager of the Beijing Institute of Biological Products, a subsidiary of Sinopharm Group, said the company has “measures in place to handle the situation if the strength and efficacy of the vaccine drops."
“We have plans to develop and produce co-strain and multi-strain vaccines,” she said.
On March 18, Professor Wang Junzhi, deputy head of an expert task force on vaccine development in China, described the Covid-19 mutations as an issue of "great importance" in a press conference with global media.
"We are taking proactive measures to develop a new generation of vaccines," he said.
How long does the protection offered by the vaccine last?
Current estimates by the UAE government suggest two doses of the vaccine may offer immunity for four to six months.
The vaccine mainly induces antibodies against one protein of the virus: the spike. These are known as anti-S or anti-spike antibodies.
Anything above 15 arbitrary units per millilitre (au/ml) is positive for the anti-S antibody test.
A typical result after the Sinopharm vaccine is anything between 50au/ml to 150au/ml.
It also generates neutralising antibodies that roughly correlate to the anti-spike antibodies.
Dr Sally Mahmoud, lab director at Biogenix Labs, part of G42 Healthcare in Abu Dhabi, said some people it is monitoring still have antibodies after almost eight months.
But in others there is a drop in antibodies after a couple of months.
How does this compare with other Covid-19 vaccines?
Most vaccine manufacturers have yet to release any data to answer this question.
In December, Moderna released a study showing its vaccine still offered good responses four months after the first vaccination.
Levels of spike antibodies and neutralising antibodies “declined slightly over time, as expected, but they remained elevated in all participants three months after the booster vaccination,” researchers in The New England Journal of Medicine said.
Can UAE residents get a third 'booster' shot of Sinopharm?
Some people have been found to have not produced Covid-19 antibodies after two doses of the Sinopharm vaccine.
These people are now being offered a third, 'booster' shot as part of a study by the UAE health department.
Residents concerned they might not have enough antibodies have been told they can check their levels, but should wait until three months after receiving the second Sinopharm jab.
If they do not have adequate immunity, then they should consult their doctor, who will refer them to the health authority for a third dose.
The UAE has ample supplies of the Sinopharm vaccine to cater for the need for third jabs, said Walid Zaher, chief research officer of G42 Healthcare, the company responsible for distributing the Chinese-made vaccine in the UAE.
Sinopharm vaccine side effects
There are no published studies yet that have focused on Sinopharm vaccine side effects. But as with other 'inactivated' vaccines the side effects appear to be mild.
Anecdotally, people report a sore arm and minor swelling, with others feeling fatigue or symptoms similar to a cold, which pass in a few days.
In contrast, messenger RNA vaccines, such as Pfizer-BioNTech and Moderna, appear to come with more side effects.
According to a US Centre for Disease Control (CDC) report, as of December 19, 112,807 people had received the vaccine.
Of these, 3,150 – or 2.8 per cent – had suffered "health impact events", listed as unable to perform daily activities, taking time off work or seeing a doctor as a precaution.
How long does protection from Covid-19 antibodies last?
Concerns have been raised that antibodies to the virus fade quickly.
A large-scale study carried out by Imperial College London in the autumn, involving 365,000 people, showed antibody levels dropped by a quarter in three months.
The findings built on previous research, which also found evidence of waning antibody counts.
One recent study from researchers at the University of Montreal showed antibody levels in the blood drop rapidly after infection.
But antibodies are only one piece of the complex puzzle when it comes to immunity.
Another study, led by the UK coronavirus immunology consortium of 100 healthcare workers six months after infection, found that while antibody levels had dropped for some people, their T-cell response, a type of white blood cell that attacks cells infected with the virus, remained robust.
The finding was replicated by other research performed in the US, which showed recovered Covid-19 patients still had enough immune cells to fight the virus eight months on.
Updated: March 25, 2021 06:41 PM