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 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 deal with different strains of the virus, but would be administered as a single shot in a similar way to annual flu shots, which currently combine four vaccines against different strains of the flu. 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 the passage of viruses from one person to another.
“There is no evidence that any of the new virus variants that have recently appeared cause a more serious 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 infecting and therefore spreading in populations that have existing partial immunity after a 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 peak protein on the surface of the Covid virus, but also another part of the virus, called the N protein.
“We hope this will result in a much broader response from the immune systems and therefore provide a much broader immunity to the virus,” Ball told the Observer. “And given what we know now about the emergence of variants of the Covid virus, which could help us strengthen protection against the disease,” he added.
The project, which also involves immunology firm Scancell and researchers at the University of Nottingham Trent, has reached a stage where production of the new vaccine has begun.
Ball said clinical trials of the vaccine were expected to begin soon.
“The plasmid that forms the basis of 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 move forward in clinical trials relatively soon.”
Scientists at the University of Bristol have started a different approach that 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 try to generate antibodies in the mucous membranes of the upper respiratory tract, you could help prevent the virus from infecting or transmitting someone,” Adam Finn said. , Professor of Pediatrics at Bristol School of Medicine, University of Bristol.
“In fact, you would create the antiviral equivalent of those United Nations blue-helmet soldiers who control war zones and prevent invasions.”
To try to achieve this, Finn and colleagues measure the levels of antibodies in the mucous secretions of people who have been given different vaccines against the disease.
“By comparing the strength of these immune responses, we may be able to predict how good they are to prevent transmission,” he added. “And from there, we could identify the vaccines that are best able to stop the spread of the virus from one person to another, in contrast to current vaccines that are evaluated primarily to the extent that they prevent develop Covid symptoms “.
This point was supported by Deborah Dunn-Walters, Professor of Immunology at the University of Surrey: “The vaccines we have developed over the past year are certainly incredible achievements, but they are not the end of history.
“We started with vaccines that provide us with about two-thirds of protection against serious illness and perhaps 50% protection against the transmission of the virus. What we need to do is improve it. There is still a lot of work to be done if we beat Covid ”.
Analyzing the numbers
After a year of some of the most disappointing news that affected the nation in modern times, there has been a dramatic shift in accounts about how we face the battle against Covid-19. According to a number of different criteria, the UK prospects emerging from the blockade, in the relatively near future, appear increasingly strong.
The number of hospitalizations, deaths and new cases has fallen in the last three weeks, while the UK vaccination program continues to surpass those of most other industrialized countries. Scientists have called for caution to move too fast in response to this rain of good news. However, there is now a palpable feeling that a significant change is taking place in the fortunes of the nation.
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This epidemic Mark Woolhouse, of the University of Edinburgh, summed up this point last week: “The data looks much better than anyone could have thought two or three weeks ago. Therefore, we must surely be able to take a more optimistic position 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 until what a point. A relatively high level of transmission blockade would have a significant impact on reducing the pandemic.
But perhaps the most encouraging of all the statistics comes from Israel, which has been the most energetic nation on the planet in vaccinating its population. As a priority target for its older citizens, it has seen hospitalization rates for those over 60 fall as compared to those for younger age groups. It is a dramatic illustration of the effectiveness of the vaccine and has clear implications for the UK, where early signs also suggest that Covid blows, in addition to blocking measures, are beginning to decline in rates of vaccination. mortality.
“Vaccine performance is good news,” Woolhouse said. “You never know at all how clinical trials will translate into a true mass vaccination program. But the numbers look great. Vaccines protect very well from serious diseases. “