Stéphane Bancel, CEO of Moderna, said in a statement that the results provided “the first clinical validation that our vaccine can prevent Covid-19 disease, including serious illness”.
Pfizer and Moderna each announced the results in press releases, not peer-reviewed scientific journals, and the companies have yet to disclose detailed data that would allow outside experts to assess their claims. Therefore, the results cannot be considered conclusive. Studies are continuing and efficacy figures may change.
Corporate products open the door to a whole new way of creating vaccines – and creating them quickly. Both use a synthetic version of the genetic material of the coronavirus, called messenger RNA or mRNA, to program a person’s cells to make many copies of a fragment of the virus. This fragment sets off alarms in the immune system and stimulates it to attack, if the real virus tries to invade. Although a number of vaccines using this technology are in development for other infections and cancers, none have yet been approved or marketed.
“The fact that two different vaccines made by two different companies with two different types of structures, in a new concept of messenger RNA, both worked so effectively confirms the concept once and for all that it is a viable strategy not only for Covid but for the future. threats of infectious disease, ”said Dr. Barry R. Bloom, professor of public health at Harvard.
Natalie E. Dean, a biostatistician at the University of Florida, said an important finding was that the vaccine appeared to prevent serious illness. Pfizer did not release information on the severity of the disease when reporting its results.
Researchers say positive results from Pfizer and Moderna bode well for other vaccines, as all of the candidates tested are aimed at the same target – the so-called spike protein on the coronavirus that it uses to invade human cells .
But it will be important to determine whether vaccines work as well in older people as they do in young people, experts say. Researchers also want to know whether vaccines are preventing people from spreading the virus – an ideal result that could help stem the pandemic.