But this does not mean that governments should throw out their AstraZeneca stocks. Experts say it is possible – and very likely – that the bullet is still effective in preventing serious disease and death.
However, the news could be a major obstacle to the world’s path out of the pandemic, which cannot ‘finish’ until the virus stops circulating widely.
The Oxford-AstraZeneca vaccine is cheaper and easier to carry and store than some of the other vaccines that have been approved for use so far and so it was going to be a key part of fighting the pandemic in low- and middle-income countries. If the vaccine is not effective enough against the new variant, it could deepen the existing vaccine gap between the richest and poorest countries in the world.
The study has not been peer-reviewed or published in full, so many unknowns remain. What we do know is that it consisted of a small number of volunteers who were mostly young and healthy and therefore not prone to severe Covid-19 infection. That meant the study did not assess protection against serious illness, hospitalization and death and many experts have said it could still prevent these findings.
“In the medium term, the most important thing is to prevent more dangerous forms of Covid-19; and it is believed that the AstraZeneca vaccine will do this,” said Dr Peter English, a consultant in the control of infectious disease, to the UK Science Media Center.
New vaccination strategy
Less effective vaccines could force countries where the new variables are gaining the upper hand to shift their vaccination strategy.
Instead of trying to achieve herd immunity, the focus may be on preventing as many deaths as possible even while the virus is circulating.
Speaking to CNN, Professor Salim Abdool Karim, who co-chairs South Africa’s Covid-19 advisory committee, said the country is likely to take a more gradual approach. , in which they assess the effect of the vaccine as it is rolled. out.
“We would start by vaccinating about 100,000 people in the first phase. We would look at the hospital standards once we have these vaccinations. And if we find that the hospitalization levels are below the level – which we are looking at – then we can be confident that the vaccine is effective … and if it is, then we can continue to roll it out, “he said.
“If we find that the hospitals are substantial – more than we expected – we would have to stop, look at where we are and maybe switch to other vaccines.”
But the AstraZeneca vaccine is a key component of major vaccine programs in many countries around the world.
The COVAX program – a consortium involving Gavi and the World Health Organization with the goal of distributing Covid-19 vaccines to poor countries – relies on this vaccine. Last week, COVAX announced a plan to roll out more than 337 million doses worldwide – including 336 million doses of the AstraZeneca-Oxford vaccine and 1.2 million doses of the Pfizer-BioNTech vaccine.
Experts from COVAX said Monday that the WHO Strategic Advisory Group of experts is finalizing new proposals for the use of the AstraZeneca vaccine and presenting them to the Director-General on Tuesday.
South African health officials said they hope to receive the first dose of Johnson & Johnson vaccine before the end of the week. The country has also ordered another 20 million vaccines through a contract with Pfizer / BioNTech, but it is unclear when these doses will arrive.
However, the AstraZeneca vaccine is, at least initially, the most affordable option for many countries.
Relieving the burden on health services
The role of a vaccine is to teach the immune system to see and fight a virus quickly. It basically helps the body remember a disease so it works faster if you get the disease. “Your own immune system will also react to clear the virus, but without the vaccine, this reaction will be slower,” said Dr. Julian Tang, an honorary associate professor and expert clinical specialist at the University of Leicester.
The currently available coronavirus vaccines work by stimulating antibodies and T-cells that have been proven to fight the original coronavirus. Antibodies work by binding and attacking the proteins on the surface of the virus – in the case of coronavirus, this is the spike protein.
If the virus changes too much, especially in its spike protein, the antibodies that stimulate the vaccine may not bind to the new version of the virus well, Tang explained.
“This means that these vaccine antibodies cannot clear as many of these viruses as you have the infection so there are more viruses left that need to be cleared by the response. your own immune system – which reacts more slowly, “he said.
“But the studies suggest that there is enough binding from these vaccine antibodies to remove at least some of the variable viruses from the system – to prevent disease and more severe death. ”
One of the main causes of pandemic disease is the number of people who need medical attention, and a relatively effective, although not very effective, vaccine would reduce the burden. seo.
There have been times when health care systems have not been able to deal with the number of incoming patients. When this happens, some patients may die because they cannot get help on time. There are other side effects to the whole system, with non-emergency treatments being postponed or postponed.
Experts argue that vaccination will be useful if it can reduce the burden on health services.
“This may look like fewer people need an ICU bed and more people are able to recover at home,” said Dr Oliver Watson, a researcher on infectious diseases at Imperial College London. adds that this could have a significant impact in cases where hospitals are very stretched. ”
This has been true in many European countries, including the UK, where the government has been able to open a number of field hospitals to disrupt the National Health System.
Hitting the vaccine
There is no doubt that the data from South Africa is a solution to vaccine campaigns but scientists are already working on updates about existing vaccines to make them more effective against new changes.
AstraZeneca said Saturday that it is working with Oxford University to modify the vaccine against the B.1.351 version and would advance it through clinical development to make it “ready for delivery in the fall if needed.” Last month, Pfizer said it was “putting down the ground work” to create a vaccine booster that could respond to coronavirus changes.
“We see this all the time with the influenza vaccine,” Tang said. Flu vaccines are modified annually to target the most circulating strains of viruses. At times, the vaccine chosen does not correspond to the common snoring.
“Inequitable vaccination seasons will increase the incidence of flu, morbidity and mortality – but to some extent this is inevitable as the virus will always be extinguished first – we need to change our vaccines accordingly. new virus, “Tang said.
UK Health Secretary Matt Hancock said on Monday that a flu plan could work for the coronavirus in the future.
“The injection has been updated each year in line with the changes and changes that have taken place and seen in recent months, and this has been done over the summer, and then on delivered into the arms of those most vulnerable to the flu in the autumn, “he said.
When it comes to Covid-19, he explained that we need to think about how we can protect people in the same way.
The good news is that developing a vaccine that would work against the new variables does not mean starting from scratch, so updates may be available soon.
“The genome of the spike protein is known to be variable, and the technology to ‘insert the genes into mRNA and vector vaccines is well established,'” English said. “Within months we hope to we will see new vaccines, adapted to the South African variety. “