Scientists are developing a series of second-generation Covid vaccines aimed at expanding protection against the disease.
Candidates include a version that could provide immune defense against many different variants of the virus, while other researchers are investigating vaccines that would generate responses specifically aimed at blocking the transmission of the disease.
Other projects include research into creating several vaccines that could address each different strain of the virus, but which would be administered as a single shot in a manner similar to the annual flu shots, which currently combine four vaccines against different strains of the flu virus. .
Covid vaccines are currently designed to stop the serious illness of infected people, to prevent hospitalizations and deaths. It is not yet known how effective they are in blocking viruses that pass from one person to another.
“There is no indication that any of the new virus variants that have emerged recently cause more severe disease than the original virus,” said Professor Jonathan Ball, a virologist at the University of Nottingham. However, there is evidence that some of these new variants may be better at infection and therefore at the spread of populations that have partial immunity following 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, called the N protein.
“We hope this should lead to a much broader response from the immune system and thus provide a much broader immunity to the virus,” Ball told Observer. “And given what we know now about the emergence of Covid virus variants, which could help us strengthen protection against the disease,” he added.
The project, which also involves immunology company Scancell and researchers at the University of Nottingham Trent, has reached a stage where the manufacture of the new vaccine has begun.
Ball said he hoped the vaccine’s clinical trials could be launched very soon.
The plasmid that underlies the vaccine has already been used in other medical treatments and is well tolerated in patients, he added. So, we hope to be able to continue our clinical trials relatively soon. ”
A different approach is being taken by scientists at the University of Bristol, who have begun to develop a vaccine that could induce antibodies in the nose and throat.
“This is the way the virus infects a person, so if you could specifically target the generation of antibodies in the mucous membranes of the upper respiratory tract, you could help block the virus from infecting someone or transmitting it,” Adam said. Finn Professor of Pediatrics at the Faculty of Medicine in Bristol, University of Bristol.
“In fact, you would create the antiviral equivalent of the United Nations soldiers’ helmet that controls war zones and prevents invasions.”
To try to do this, Finn and colleagues measure the levels of antibodies in the mucous secretions of people who have been given various vaccines against the disease.
“Comparing the strength of these immune responses, we may then be able to predict how good they are at preventing transmission,” he added. “And from there, we could identify vaccines that are best able to stop the spread of the virus from one person to another – unlike current vaccines that are evaluated primarily on how well they prevent the development of Covid symptoms.”
This point was made by Deborah Dunn-Walters, Professor of Immunology at the University of Surrey: “The vaccines we have developed over the last year are undoubtedly incredible achievements, but they are not the end of the story.
“We started with vaccines that can give us about two-thirds protection against serious diseases and maybe 50% protection against the transmission of the virus. The thing we need to do is improve this. There is still a lot to do if we want to defeat Covid. ”
Analyzing the numbers
A year after some of the most discouraging news affecting the nation in modern times, there has been a dramatic shift in accounts of how we are doing in the fight against Covid-19. According to a number of different criteria, the outlook for the UK emerging from the stalemate in the relatively near future looks increasingly strong.
The number of hospitalizations, deaths and new cases has fallen over the past three weeks, while the UK vaccination program continues to outpace those of most other industrialized nations. Scientists have called for caution about moving too fast in response to this rain of good news. However, there is now a palpable feeling that there is a significant change in the nation’s wealth.
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This point was summed up by epidemiologist Mark Woolhouse of the University of Edinburgh last week: “The data looks much better than anyone might have thought two or three weeks ago. So we certainly need to be able to take a more optimistic stance on what is now safe to do. ”
To a large extent, other research suggests that both Pfizer and AstraZeneca vaccines – which were designed primarily to prevent serious disease – also reduce the transmission of the virus from one person to another – although it is not yet clear how much. A relatively high level of transmission blockage would have a significant additional impact on reducing the pandemic.
But perhaps the most encouraging of all the statistics comes from Israel, which was the most energetic nation on the planet in vaccinating its population. Targeting older citizens as priorities, he found – as a result – hospitalization rates for people over the age of 60 are falling compared to those for younger age groups. It is a dramatic illustration of the vaccine’s effectiveness and has clear implications for the UK, where early signs also suggest that Covid blows – in addition to blocking measures – are starting to reduce mortality.
“The vaccine’s performance is very good news,” Woolhouse said. “You never know how clinical trials will translate into a real mass vaccination program. But the numbers look great. Vaccines protect very well against severe diseases. ”