Monkeys vaccinated or infected with the new coronavirus have developed antibodies that allow them to be protected against a new infection, according to two “promising” studies despite the big differences between macaques and humans, published Wednesday by the journal Science.
“Our findings increase optimism that it will be possible to develop vaccines against Covid-19,” said Dan H. Barouch, the researcher who conducted the two studies at the Beth Israel Deaconess Medical Center (BIDMC), in a statement. , in Boston.
“New research will be needed to answer important questions about the duration of protection” as well as the specifics of SARS-CoV-2 vaccines developed for humans, he said, while the pandemic has already done more 325,000 dead worldwide since its appearance in December in China.
These studies, “among the first to demonstrate that non-human primates can develop protective immunity against SARS-CoV-2, are promising,” praised the scientific journal Science.
“Neutralize the virus in two weeks”
In the first study, nine adult macaques were infected with SARS-CoV-2 virus. After recovering, they were re-infected 35 days later. All of them then showed “little or no symptoms”.
“These data indicate that an infection with SARS-CoV-2 has caused protective immunity“in macaques, conclude its authors while emphasizing the” important differences “in the contagion to the coronavirus in macaques and humans.
In the second study, the researchers gave experimental vaccines to 35 adult macaques.
When these monkeys were nasally infected with SARS-CoV-2 six weeks later, “they had sufficient levels of antibodies in the blood to neutralize the virus in two weeks,” said Science.
These levels were similar to those detected in recovering humans after being infected with the new coronavirus, the researchers said.
“Those are very encouraging studies“said Lawrence Young, a researcher at the University of Warwick who was not involved in the work.
But infections with the new coronavirus “would be different in humans, including the ability of the virus to infect many other tissues and cells in humans. The immune responses would also be very different,” he warns.
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