Scientists are developing a range of second-generation Covid vaccines to increase protection against the disease.
Candidates include one version that could provide immune defense against many different virus variants, while other researchers are investigating vaccines that would generate responses specifically aimed at blocking the transmission of the disease.
Other projects include research into the creation of multiple vaccines that could each fight different strains of virus, but which would be delivered as a single shot in a manner similar to annual flu shots, which currently combine four vaccines against different strains of the flu virus.
Currently, Covid vaccines are designed to prevent infected people from becoming seriously ill, to prevent hospitalizations and deaths. It is not yet known how effective they are in blocking viruses that are transmitted from person to person.
“There is no evidence that any of the new virus variants that have recently appeared cause more serious illness than the original virus,” said Professor Jonathan Ball, a virologist at the University of Nottingham. “However, there is some evidence that some of these new variants may be better at infecting and therefore spreading in populations that have pre-existing partial immunity after natural infection or vaccination.”
One possible solution is a vaccine – now being developed by a team of scientists, including Ball – that targets not only the spike protein on the surface of the Covid virus, but also another part of the virus, the N protein.
“Hopefully this should result in a much broader immune system response and thus a much broader immunity to the virus,” Ball told the reporter. Observer“And given what we now know about the emergence of Covid virus variants, that could help us strengthen our protection against the disease,” he added.
The project, which also involves the immunology company Scancell and researchers from Nottingham Trent University, has reached a stage where production of the new vaccine has begun.
Ball said it was hoped that clinical trials of the vaccine could be launched very soon.
“The plasmid that forms the basis of the vaccine has already been used in other medical treatments and is well tolerated by patients,” he added. “So we are hopeful that we can continue with clinical trials relatively quickly.”
A different approach is being taken by Bristol University scientists who have begun to develop a vaccine that can trigger antibodies in the nose and throat.
“That’s the way the virus infects a person, so if you could specifically aim to generate antibodies in the lining of the upper respiratory tract, you could help prevent the virus from infecting or being passed on,” said Adam Finn , Professor of Pediatrics at Bristol Medical School, University of Bristol.
“In effect, you would create the antiviral equivalent of those United Nations blue helmet soldiers who control war zones and prevent invasions.”
To achieve this, Finn and colleagues measure antibody levels in the mucosal secretions of people who have received various vaccines against the disease.
“By comparing the strength of these immune responses, we may be able to predict how good they are at preventing transmission,” he added. And from there we were able to identify vaccines that are best able to stop the spread of the virus from one person to another – unlike current vaccines that are primarily assessed for how well they develop Covid symptoms. appearance.”
This point was supported by Deborah Dunn-Walters, professor of immunology at the University of Surrey: “The vaccines we’ve developed over the past year are unquestionably incredible achievements, but they are not the end of the story.
“We have started with vaccines that give us maybe about two-thirds of protection against getting serious disease and maybe 50% protection against passing on the virus. What we need to do is improve this. There is still a lot of work to be done if we are to beat Covid. “
Analysis of the figures
After a year of the most daunting news plaguing the nation in modern times, there has been a dramatic change in the stories of how we fare in the fight against Covid-19. By a wide variety of criteria, the outlook for the UK to emerge from lockdown in the relatively near future looks stronger and stronger.
Hospitalizations, deaths and new cases have fallen sharply over the past three weeks, while the UK’s vaccination program continues to outpace that of most other industrialized countries. Scientists have urged caution not to act too quickly in response to this barrage of good news. Nevertheless, there is now a palpable sense that a significant change in the nation’s fortunes is taking place.
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This point was summed up last week by epidemiologist Mark Woolhouse of the University of Edinburgh: “The data looks much better than anyone could have imagined two or three weeks ago. So we certainly need to be able to take a more optimistic view of what is now safe to do. “
For the record, other research suggests that both the Pfizer and AstraZeneca vaccines – which were primarily designed to prevent serious illness – also reduce the transmission of the virus from one person to another – although it is not yet it is clear by how much. A relatively high level of transmission blocking would have a further significant effect on mitigating the pandemic.
But perhaps the most encouraging of all the statistics comes from Israel, which is the most energetic nation in the world at population vaccination. By targeting most older citizens as a priority, it has – as a result – seen the number of hospital admissions for over-60s drop compared to those for lower age groups. It’s a dramatic illustration of the vaccine’s effectiveness and has clear implications for the UK, where early signs also suggest that Covid shots – in addition to lockdown measures – are starting to lower death rates.
“The effect of the vaccine is really good news,” said Woolhouse. “You never know exactly how clinical trials will translate into a true mass vaccination program. But the numbers look very good. The vaccines protect very well against serious diseases. “