Hopes of getting a Covid-19 vaccine were boosted again today after an experimental Chinese jab was found to be safe and produce an immune response.
Every volunteer given a double-dose of state-owned firm Sinopharm’s vaccine made antibodies against SARS-CoV-2, the coronavirus that causes Covid-19.
In theory, this would protect them from catching the virus again in the future, or at least protect them from developing a severe bout of the disease. But this has not been proven by the scientists yet — they only injected fewer than 1,000 participants.
Ministers repeatedly insisted Britain could start to use a Covid-19 jab by September — but the Government has still yet to approve any vaccine because of a lack of data that they work.
Number 10’s own vaccine tsar yesterday admitted the odds of getting one rolled-out before Christmas were ‘slim’, with World Health Organization officials now claiming one won’t be ready until 2021 at the earliest for the most vulnerable.
Oxford University’s experimental jab is considered the front-runner but Downing St has also bought supplies of 340million different vaccines, in a spread-betting approach to ensure the UK doesn’t miss out on any scientific breakthrough.
The results of the first two phases of clinical trials of Sinopharm’s vaccine, published in The Lancet, come after experts released promising results of another candidate jab made by Pfizer and its German partner.
The Chinese state-owned enterprise Sinopharm published the results of its first two phases of clinical trial in the medical journal the Lancet today. Pictured, Sinopharm vaccine samples in a Beijing lab in April
All participants given the jab BBIBP developed antibodies against SARS-CoV-2, the virus that causes Covid-19. Pictured: A staff member tests samples of a Sinopharm vaccine
A vaccine is considered key to ending the Covid-19 pandemic because it ensures a person will not catch the coronavirus.
All hopes are being pinned on finding one proven to work, but until then, measures such as social distancing have to be used to prevent the virus spreading.
More than 600 healthy adults were given Sinopharm’s jab, dubbed BBIBP, and none suffered an adverse reaction.
The most common side effect, reported by a quarter of volunteers, was pain at the point the needle was injected — which is common for any jab.
Two doses were shown to be more powerful than one, which is typical for the way BBIBP is made.
It is an inactivated vaccine, meaning it contains the virus but it has been grown in a laboratory and then killed, so it is not infectious.
Inactivated vaccines are well known and have been used against diseases such as influenza, measles and rabies. But they usually don’t provide immunity that’s as strong as live vaccines, so several doses over time may be necessary.
Adults over the age of 60 took a longer time to mount immunity, according to the results of the study, carried out by Beijing Institute of Biological Products.
But all volunteers had antibodies — proteins of the immune system which fight infection — seven weeks after injection compared with four in those under 60 years old.
This is not unusual because the immune system slows with ageing, meaning it takes longer for older people to respond to a vaccine or illness. It is also seen for influenza vaccines.
Antibodies are produced by B-cells in the immune system. They can take several days to build up.
They are stored by the immune system so that if the virus enters the body again, they can react faster to clear it from the body before it makes a person sick.
Pictured: How antibodies grew in volunteers given the jab over time (A is under 60 years old and B is 60 to 80 year olds). ‘Seroconversion rates’ refers to how many people developed antibodies. The graphs show 100 per cent of under 60 year olds developed antibodies within 28 days, regardless of the dose. But it took longer, 42 days, in the older cohort
The greatest antibody responses were made when participants were given two 4mg doses either 21 days or 28 days apart (green and purple bars)
SINOPHARM OFFERS FREE JABS TO THE PUBLIC, INCLUDING STUDENTS, OUTSIDE TRIALS
A division of Sinopharm, that is developing two Covid-19 vaccines, is offering them for free to Chinese nationals, including students.
State-owned Sinopharm subsidiary China National Biotec Group Co (CNBG) has given the vaccine to 350,000 people outside its clinical trials, which have about 40,000 people enrolled, a top CNBG executive said recently.
The move by CNBG is reportedly aimed at boosting public confidence in jabs developed in China.
It’s unusual to offer people vaccines outside of clinical trials and before final regulatory approval for general use. It raises ethical and safety questions, as companies and governments worldwide race to develop a vaccine that will stop the spread of the coronavirus.
Chinese companies earlier drew attention for giving the vaccine to their top executives and leading researchers before human trials to test their safety and efficacy had even begun.
In recent months, they have injected a far larger number under an emergency use designation approved in June, and that number appears poised to rise.
Chinese students going abroad for higher studies were encouraged to sign up for a free jab this month, the Wall Street Journal reported.
The announcement of the company distributing vaccines to students appeared on a website where people could sign up to receive it, the newspaper reported.
The website said on Monday that 481,613 people had taken the vaccine while an additional 93,653 had applied to be inoculated.
The website was down starting Tuesday, the report said, adding that it was ‘under maintenance’.
Now, large Chinese firms including telecom giant Huawei and broadcaster Phoenix TV have announced they’re working with Sinopharm to get the vaccine for their employees.
Another company, Sinovac Biotech, has injected 90 per cent of its employees and family members, or about 3,000 people, most under the emergency-use provision, CEO Yin Weidong said.
It has also provided tens of thousands of rounds of its CoronaVac to the Beijing city government.
Separately, the Chinese military has approved the use of a vaccine it developed with CanSino Biologics Inc., a biopharmaceutical company, in military personnel.
Diego Silva, a lecturer in bioethics at the University of Sydney, said that giving vaccines to hundreds of thousands outside of clinical trials doesn’t have ‘scientific merit’ in China, where there are currently very few locally transmitted cases, and incoming arrivals are quarantined centrally.
‘If it’s in the US where the virus is still raging that’s a bit different. But in a country like China it doesn’t seem to make sense to me,’ he said. ‘Because there’s not enough of the virus in China locally to deduce anything, you’re introducing a whole host of others factors by injecting people outside of trials.’
Despite the trial being carried out by Sinopharm itself, independent scientists were hopeful.
Writing in a linked Comment article, Professor Larisa Rudenko, from the Institute of Experimental Medicine, Saint Petersburg, Russia, said described the findings as ‘promising’, but said ‘more studies are needed to establish’ whether the vaccine promotes T cells — a type of white blood cell to attack the virus.
Dr Andrew Preston, a reader in microbial pathogenesis involved in vaccine development, Department of Biology and Biochemistry, University of Bath, said it the progress was ‘good news’.
He told MailOnline: ‘This trial was different to others that it included over 60’s, one of the key cohorts who we want to protect through vaccination. The same safety profile was observed in the older group as in younger groups.’
However, he added: ‘This doesn’t really change the picture an awful lot. Yes, it’s another vaccine through the initial Phase 1/2 testing which is good.
‘But of course this does not tell us whether the vaccine actually protects against infection and/or disease.’
He also said the study does not appear to have studied T cells ‘which are likely to be important for protection against Covid-19’.
‘It’s likely that we’ll need several different vaccines to cover different scenarios and to help fill demand,’ he said. ‘Passing this testing stage enables it to move onto larger trials in which the effectiveness of the vaccine in terms of protection can be evaluated.’
Sinopharm has two vaccines in final stage clinical trials, and China has eight overall, putting the country at the forefront of the quest to end the pandemic.
The Beijing-based firm recently said its other vaccine contender may be on the market by December and cost just £100 for two doses.
Other front-runners include Oxford University, whose vaccine will be produced on mass by AstraZeneca, Pfizer and Moderna.
The study findings today come from Sinopharm’s vaccine being trialled by Beijing Institute of Biological Products.
Trials for its other vaccine, the one which may be ready by Christmas, are being co-ordinated by the Wuhan Institute of Biological Products.
The BBIBP-CorV vaccine used in the study reported is based on a sample of the virus that was isolated from a patient in China, where the coronavirus first emerged in December 2019.
Supplies of the virus were grown in a laboratory and then killed using a chemical called beta-proprionolactone.
BBIBP-CorV includes the dead virus mixed with aluminium hydroxide — an adjuvant which can boost the immune response.
Adjuvants are sometimes added to reduce the amount of vaccine protein required per dose, which allows more doses to be made quicker.
The first phase of the study was designed to find the optimal safe dose for BBIBP-CorV and involved 192 people.
Half were aged between 18 and 59 years, and the other half were aged between 60 years and 80 years.
A total of 144 participants received the vaccine. Forty-eight received the placebo or ‘dummy’ vaccine so researchers can compare the side effects.
Participants were asked to report any adverse events for the first seven days after each vaccination, and these were investigated by the research team to see if there was any organ damage.
No serious adverse events were reported within 28 days after vaccination.
The most common side effect, reported by 24 per cent, was pain at the injection site. Only six per cent of those in the placebo group complained of this.
A small number (four per cent) of participants reported experiencing a fever, another more common side effect of receiving a vaccine which signals the body is working to produce an immune response. Six per cent of those given the placebo reported this.
There were no instances of clinically significant changes in organ functions detected in laboratory tests in any of the groups.
Within the two age groups, volunteers given the Sinopharm jab were given different dose levels, twice, 28 days apart. These were 2mg, 4mg and 8mg.
The second phase of the study was designed to identify the best timing of doses.
A total of 448 participants aged between 18 and 59 years were randomly assigned to receive either a vaccine or a placebo. Some 336 received the vaccine and the remaining 112 the placebo.
Some of those given the vaccine received one 8mg shot. The rest were given two shots of 4mg on a schedule — either 14 days, 21 days or 28 days after the first jab.
Blood samples were taken of all 640 participants in the first and second phase of the study to test antibody levels for SARS-CoV-2 before and after vaccination.
The greatest antibody responses were made when participants were given two 4mg doses either 21 days or 28 days apart.
Professor Xiaoming Yang, one of the authors of the study, from the Beijing Institute of Biological Products Company Limited, Beijing, said: ‘Our findings indicate that a booster shot is necessary to achieve the greatest antibody responses against SARS-CoV-2 and could be important for protection. This provides useful information for a phase 3 trial.’
Inactivated vaccines work differently to live vaccines, and often multiple doses are necessary to build up and maintain immunity. For example with measles, two doses are needed.
Participants aged 60 and over were slower to respond, taking 42 days before antibodies were detected in all recipients compared with 28 days for participants aged 18-59.
Antibody levels were also lower in those aged 60-80 years compared with those aged 18-59.
Professor Yang said: ‘Protecting older people is a key aim of a successful COVID-19 vaccine as this age group is at greater risk of severe illness from the disease.
‘However, vaccines are sometimes less effective in this group because the immune system weakens with age.
‘It is therefore encouraging to see that BBIBP-CorV induces antibody responses in people aged 60 and older, and we believe this justifies further investigation.’
Phase three of the clinical trials, the final stage, will assess whether these antibody responses actually protect people from disease.
Sinopharm said in July that its other vaccine could be ready for public use by the end of this year after the conclusion of final trials.
Chairman of Sinopharm Group Liu Jingzhen said, according to Guangming Ribao newspaper: ‘After the third stage of international clinical trials ends, we can register the inactivated vaccine.
‘According to our estimations, by the end of the year, it may appear on the market.
‘I have personally received two shots of the vaccine, there were no side effects.
‘After the inactivated vaccine enters the market, its price will not be too high, it will be around several hundred yuan. Two shots will cost about 1,000 yuan (about $144/£100).’
China also has a vaccine candidate each from Sinovac and CanSino, which are both in phase three trials.
SINOPHARM’S OTHER VACCINE ALSO TRIGGERS ANTIBODIES
Sinopharm’s other experimental jab, the trials of which are being co-ordinated by the Wuhan Institute of Biological Products, has been shown to trigger antibodies in volunteers.
Although the findings are promising, they do not prove the jab can prevent a person catching the virus.
Results of the most recent trial were published on August 13 in the Journal of the American Medical Association (JAMA) and led by Shengli Xia, of the Henan Center for Disease Control and Prevention.
Ninety-six healthy adults from China aged between 18 and 59 years old were assigned to one of the three dose groups (2.5, 5, and 10 μg/dose), or a control group for a placebo jab.
They were given three shots in total, on days 0, 28, and 56.
After seven days, adverse reactions occurred occurred in 20.8 per cent, 16.7 per cent, and 25 per cent of patients in the low-dose, medium-dose, and high-dose groups, respectively.
In the second trial, 224 healthy adults were randomly divided into two groups in which they received a jab on either day zero and 14, or day zero and 21. Some received a medium dose of the real vaccine candidate, while the others were given a placebo.
No more than one fifth of participants in the phase two trial had side effects.
Overall, 15 per cent of participants reported side effects within seven days of the injection, which is ‘lower compared with results of other candidate vaccines’, the researchers said.
The most common side effect was injection site pain. No serious adverse reactions were noted by the researchers.
When looking at the immune response to the vaccine, the trial found ‘the inactivated vaccine may effectively induce antibody production’ based on antibody levels increasing.
The results in both phases indicated that a longer interval (21 to 28 days) between the first and second injections produced higher antibody responses compared with a shorter interval schedule (14-day group).
Antibodies started to increase after a second injection and further increased after the third injection in the phase 1 trial, suggesting the need for a booster injection, the paper said.
No new Covid-19 cases were reported and no participant developed any symptoms of SARS-CoV-2 infection during the trial.
But its not clear if people were protected by the jab or if they had just not been exposed to the coronavirus. And the researchers did not look at home long antibodies lasted in the long-term.
Source: Daily Mail | Health News