[ad_1]
Oxford University researchers suggest standardized parameters for comparing candidates for covid-19 vaccines and, after their approval, recommend complementary studies to evaluate efficacy against severe disease cases, in a paper published today.
In the article published in the scientific journal The Lancet Infectious Diseases, the two experts argue that a meaningful comparison between the various vaccine candidates against covid-19 will only be possible if the teams collaborate and evaluate the effectiveness of the vaccine based on standardized methods.
“It is unlikely that we will have a single winning vaccine in the race against covid-19. Different technologies will bring different benefits that will be relevant in different situations, ”explains Susanne Hodgson, one of the authors, quoted in a statement.
Currently, 44 candidates are undergoing clinical evaluation and a further 154 are in preclinical development, with different technologies.
For this reason, the authors call, it would be important for the various research groups working on a covid-19 vaccine to apply quantifiable and standardized parameters during clinical trials and to be clear about the limits, to facilitate comparison of their efficiencies.
“Adopting a standardized approach to measuring vaccine success in clinical trials will be important in making meaningful comparisons so that the most effective candidates have wider use,” says Susanne Hodgson.
On the other hand, the researchers also state that clinical trials may not be sufficient to determine whether a vaccine can protect against serious illness or death from covid-19, recommending continuous, long-term studies after licensing. and the implementation of a candidate.
In the clinical trial phase, it would be possible to carry out this evaluation only with an extremely large number of volunteers to ensure a reliable measure of vaccine efficacy.
“To determine whether a vaccine protects against severe covid-19, a clinical study must show that there are significantly fewer cases of serious disease in vaccinated individuals than in those who did not receive the vaccine. But only a small fraction of those infected with SARS-CoV-2 develop a serious disease, ”explains second author, Kate Emary.
Therefore, he adds, it will probably be possible to understand the effectiveness of a vaccine in these cases only after it has already been administered to a large population and, at that time, it will be necessary to conduct long-term studies, which will also allow to ensure continuous evaluation. of its safety.
Furthermore, any controlled human infection studies (so-called “human provocation studies”), despite allowing a rapid assessment of the vaccine efficacy, may not be sufficient to predict this efficacy in the elderly, as it is likely to include only young volunteers.
Last week, a team of researchers from Imperial College London (ICL) announced a “human challenge study” with the virus that causes covid-19 to explore, in a first phase, the feasibility of exposing healthy people to SARS-CoV-2 and then studies how potential vaccines work in the body to stop or prevent covid-19.
In this study, only young people between the ages of 18 and 30, with no history or symptoms of covid-19, with no known health problems or adverse risk factors for covid-19, such as heart disease, diabetes, or obesity.
However, the authors of the article published in the Lancet journal today caution that the relationship between vaccine efficacy in young subjects and older and at-risk populations in this type of study is still unclear.
The researchers also point out that although some countries can implant vaccines against covid-19 only on the basis of data on their safety and immunogenicity, the goal of developing a vaccine is to have direct evidence of its effectiveness in protecting against infections and diseases. , in order to selectively increase the production of effective vaccines.
[ad_2]
Source link
