A coronavirus shot may not provide complete immunity to the disease, the head of the British Vaccine Task Force warned today.
Kate Bingham told MPs that she was convinced the world would have some form of Covid-19 vaccine in early 2021.
But she said she was less optimistic that the shot might protect against contracting the infection and is more likely to only reduce the severity of the symptoms.
Ms Bingham warned that the shot could be so weak that the elderly should take two doses to fight the disease.
A Covid-19 vaccine is being touted as a quick fix for the pandemic that could end the social distance measures that are used around the world.
For example, the MMR shot almost guarantees that someone will never get measles, mumps and rubella.
But experts say vaccines with Covid-19 are more similar to those that protect against the flu – reducing the risk of developing severe symptoms if an infection does occur.
Kate Bingham told MPs today that she was sure the world would have some form of vaccine against Covid-19 in early 2021. But she said she was less optimistic that the shot might protect against contracting the infection and that the vaccine is more likely to reduce the severity of the symptoms
Professor Sarah Gilbert, who leads the development of the Oxford University lamprey, said the elderly may need two injections of the vaccine
Ms Bingham told the House of Commons Science and Technology Committee: “I am relatively optimistic that we will find a vaccine that can treat the population.
“The caveat is … is it a completely sterilizing vaccine, which means you can’t get infected, or is it a vaccine that basically just removes the symptoms so it reduces mortality?
‘It is clear that we would like to have a sterilizing vaccine so that people do not get infected.
“But in the short term, we may have to settle for a vaccine that will reduce the severity of the disease, and I’m fairly optimistic that we’ll get it.
“I don’t have a strong idea of how quickly it will take before we get a sterilization vaccine.”
There are still no proven injections for other coronaviruses such as SARS and MERS, despite dozens of attempts to develop them for nearly two decades.
How the injectable vaccines from Imperial College London and Oxford University would work
What is the difference between the vaccines being developed by Oxford University and Imperial College?
The science behind both vaccines depends on recreating the ‘peak’ proteins found everywhere in the outside of the COVID-19 viruses.
Both will attempt to mimic or mimic these spikes in the body. The difference between the two is how they achieve this effect.
Imperial College London will attempt to deliver genetic material (RNA) from the coronavirus that programs cells in the patient’s body to recreate the spike proteins. It transports the RNA through liquid drops that are injected into the bloodstream.
The University of Oxford team, on the other hand, will genetically engineer a virus to look like the coronavirus – to have the same spike proteins on the outside – but cannot cause infection in a person.
Attenuated by genetic engineering, this virus is a type of virus called adenovirus, the same virus that causes colds and has been removed from chimpanzees.
If the vaccines can successfully mimic a person’s bloodstream peaks and stimulate the immune system to produce special antibodies to attack it, this could train the body to destroy the real coronavirus if they get there in the future get infected with it.
The same process is believed to happen in people who actually catch COVID-19, but this is much more dangerous – a vaccine has the same endpoint, but does not cause disease.
Experts say that one of the main reasons for these failed attempts was that investment dried up as the outbreaks drained due to contact detection and social distance.
But because the coronavirus pandemic has paralyzed the global economy, developing vaccines have benefited from an abundance of funding.
The UK has invested hundreds of millions of pounds in injections made by Oxford University, the precursor to the world’s first vaccine, and Imperial College London.
Professor Sarah Gilbert, who leads the development of the Oxford University lamprey, reiterated that the elderly may need two injections of the vaccine.
She told MPs: “We have previously vaccinated with this type of vaccine technology and have seen good immune responses in older adults and people in their eighties.
‘It’s about determining whether it works at all, but in older people the immune response is significantly less.
If it turns out you may be able to get around it by giving a stronger dose or an extra dose to try to get their immune response to the same level that you see in younger people.
Ms Bingham added: “I think it is important to understand that these vaccines may not be given all at once and in many cases they are already predicted to need two doses to generate that immunity, so that’s another aspect to keep in mind when building this vaccine portfolio. ‘
The Oxford vaccine, which is leading the global race, is currently being tested on more than 10,000 people in Britain, Brazil and South Africa after moving to Phase III studies.
Scientists have had to move trials abroad because there are now so few cases of the coronavirus in the UK community.
Meanwhile, Imperial College London vaccine has now switched to human trials and no signs of effects have been reported.
Their vaccine candidates work by training the body to identify the coronavirus so that it can quickly fight the disease before it has a chance to cause an infection.
The injectable vaccines from Oxford and Imperial are two of the frontrunners for curing the disease, but the researchers behind them admit they won’t be perfect.
Competitive universities said today that they could eventually be used together to provide long-term immunity.
Scientists around the world increasingly believe that booster jabs will be needed to maintain protection against the virus that causes Covid-19, because the initial immunity provided by a vaccine may fade over time.
Natural immunity to other coronaviruses, which cause colds, is thought to last from several months to several years.
The possible flaw with the Oxford vaccine is that it uses a harmless virus as a microscopic Trojan to smuggle small fragments of Covid-19 coronavirus RNA – the bug’s genetic blueprint.
The recipient’s immune system learns to identify this RNA as foreign, creating antibodies to protect against it.
But experts fear that if a person is exposed to multiple doses of this shot, their bodies may ‘accidentally’ develop an immune response to the Trojan horse virus itself – called an adenovirus – making it unusable.
British health secretary Matt Hancock announced last month that first-line NHS and health care providers, those over 50 and British people with heart or kidney disease would be the first to receive a Covid-19 vaccine.