Cop: Is it feasible to mix different new crown vaccines?

, Feb. 14 (Xinhua Zhang Ying) Many countries around the world are facing the pressure of insufficient supply of new crown vaccines, especially in low-income countries, "one dose is hard to find" problem has been widely concerned. Globally approved new crown vaccines typically require two doses. If different vaccines can be mixed in two vaccinations, the flexibility of the vaccine supply will be greatly increased. Is this strategy feasible? The UK has launched trials to find out.
clinical trial led by researchers at oxford University will explore the feasibility of using different new crown vaccines in the first and second doses of "enhanced needles," the University of Oxford said in a press release. The trial received 7 million pounds ($9.68 million) in funding from the British government's vaccine team.
researchers will recruit more than 800 volunteers aged 50 and over from eight sites supported by the National Institutes of Health, starting with an assessment of the effectiveness of vaccines developed jointly by Oxford University and AstraZenecom Pharmaceuticals of the United Kingdom, as well as vaccines developed by Pfizer in the United States in collaboration with Biotech Germany. If more new crown vaccines are approved in the UK in the future, they could also be included in the trials.
trial will also assess the effectiveness of the first dose and the "enhanced needle" vaccination at intervals of 4 or 12 weeks, respectively. By analyzing blood samples from volunteers, the researchers will monitor the effects of different vaccination programs on volunteers' immune responses, as well as possible adverse reactions to vaccine mixing.
"If we do show that these vaccines can be used alternately in the same (vaccination) program, we will greatly increase the flexibility of the vaccine supply," Matthew Snepp, lead researcher on the trial and an associate professor at Oxford University, said in a statement.
the two vaccines selected in this trial follow different technical routes, oxford University and AstraZeneta have developed a adenovirus vector vaccines, while Pfizer and Biotech have developed an mRNA (messenger RNA) vaccine. Both vaccines target the new coronavirus prickly protein, which triggers an immune response by delivering genetic material or genetic information to the body.
strategies for mixing different vaccines have previously been used in the prevention and control of infectious diseases such as Ebola. Johnson and Johnson's Janssen Pharmaceuticals' Ebola vaccine program, approved by the European Union's
in 2020, is a two-dose, different vaccine to prevent a certain type of Ebola virus infection.
, England's deputy chief medical officer, said the trial of the new crown vaccine would give people a better understanding of how to fight the "difficult" disease. Vaccine use has the potential to enhance the immune response, produce higher antibody levels and last longer.
the trial could provide clues as to how the new crown vaccine could work against more new strains.
health agencies are now cautious about vaccine mixing until clinical trial data are available. Mary Ramsay, Director of Immunization at Public Health England, has previously said the agency does not recommend mixing two vaccines and that people should use the same vaccine when injecting the second dose after the first dose.
The U.S. Centers for Disease Control and Prevention notes that the two new mRNA vaccines approved in the U.S. cannot be used interchangeable or mixed with other new crown vaccines unless it is not possible to determine which new crown vaccine is being injected in the first dose, or in exceptional circumstances such as the first dose of a new crown vaccine being provided for a second dose, before another new crown vaccine can be given at least 28 days apart.
the scientific question of mixing different new crown vaccines, scientists are still exploring.