Unvaccinated Omicron infected people are not immune to other variants
Science and Technology Daily, Beijing, May 19 (Reporter Zhang Mengran) A new study published in the journal Nature on the 19th by researchers at the University of California, San Francisco and its affiliated Gladstone Institute shows that in unvaccinated people , infection with the new crown Omicron variant provides little long-term immunity to other variants.
However, vaccinated individuals infected with Omicron developed immunity to other variants.
This time, colleagues of Melanie Otto, director of the Gladstone Institute of Virology, used a mouse model to study infection caused by wild-type new coronavirus (WA1), Delta and Omicron, and reported that Otto The Mikron infection was significantly milder and produced a lower immune response than the WA1 and Delta infections.
The research team collected sera from mice 7 days after infection and tested the neutralization efficiency of these sera against WA1, Alpha, Beta, Delta, and Omicron infection.
Serum from mice infected with Omicron only induces neutralizing ability against Omicron.
In contrast, sera from delta mice showed effective neutralization of WA1, alpha, beta, and delta, as well as partial neutralization of omicron; sera from WA1-infected mice WA1 and Alpha can produce effective neutralization and partial neutralization of beta and delta.
These findings were replicated 9 days after infection.
Subsequently, the research team used the sera of 10 unvaccinated individuals who recovered from Omikron infection to confirm that Omikron infection did not provide effective neutralization of other new coronavirus variants.
Consistent with what was observed in mice, the sera from these individuals were only effective in neutralizing the Omicron variant.
However, sera from vaccinees with confirmed Omicron or Delta breakthrough infections showed potent neutralization of all variants.
The results of the study show that the "breakthrough infection" of Omicron or Delta after vaccination can enhance existing immunity by mobilizing "mixed immunity" against all mutant strains and providing broad-spectrum protection against infection .
In other words, based on existing results, the researchers believe that unvaccinated people infected with Omicron have little or no protection, while vaccinated people will be more broadly protected, or may be protected from future variants, Especially if they have a "breakthrough infection".