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Arne Akbar, professor of immunology at UCL and president of the British Society for Immunology, said scientists had to figure out what goes wrong with the immune system as people age.
“One thing that is evident, even in healthy older people, is that there is more inflammation throughout the body. We need to understand where that inflammation comes from, ”he said. “And this benchmark inflammation in older people is related to frailty and many negative results as we age. And this seems to be exacerbated when you have a serious infection like Covid-19.
“But what is the source of the inflammation in the first place? That’s something we really need to deal with. “
Akbar said something else might be needed along with the vaccine for older people, such as the steroid drug dexamethasone, which can block inflammation caused by the virus and has been shown to save lives in Covid-19.
“So for older people, you may have something like an anti-inflammatory medication, like perhaps dexamethasone, along with vaccine responses to give you the maximum benefit.
“Only the vaccine will help younger people, and that will be good, because if younger people are not infected, they will not pass it on to older people. But it will not directly help the older group, and they are the people who have the most serious disease right now. “
The committee took evidence when the University of Oxford announced successful trials of two doses of its candidate vaccine in pigs, which respond similarly to humans. The Pirbright Institute, in collaboration with vaccine scientists, established that two doses resulted in a significantly higher antibody response than one dose.
“It is not yet known what level of immune response will be required to protect humans against Sars-CoV-2. Vaccine efficacy trials are being conducted in humans, and if the efficacy result is lower than expected after a single dose, it is important to know whether administering two doses could result in an increased immune response, which could be more protective. ” a declaration.
Sarah Gilbert, a professor of vaccinology at Oxford University, who directs her research on Covid-19 vaccines, told the Lords committee that none of the 140 vaccines in development would likely be perfect, but said that a useful vaccine did not have to be 100% effective.
“Even with 50% accuracy, we could go a long way in protecting the population. Therefore, we are optimistic that we will have something and, if necessary, we can combine vaccines to get something that works even better, “he said.
As the number of people infected with coronavirus drops in England and the rest of the UK, it becomes more difficult to test vaccines there, so she and her colleagues have embarked on a trial in Brazil, where the numbers are high and they are about to begin. in South Africa too. Astra Zeneca, for whom the vaccine is licensed, is preparing a trial of 30,000 people in the United States, he said.
The first sign that any vaccine is working will help researchers around the world, he said.
“As soon as we get a signal of efficacy and we can compare that to the level of immunity we’re building, that gives all vaccine developers really useful information, to let them know if their vaccines are likely to work as well and if it will be a or two doses, and in older people and younger people. Therefore, the first sign of effectiveness will be really important and we still don’t know which country will generate that. “
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