For months, scientists, public health officials, politicians and the general public have debated whether prior SARS-CoV-2 infection — touted as “natural immunity” — offers protection against COVID-19 that is comparable to vaccines.
Yahoo News spoke to two experts about natural immunity and vaccine-induced immunity in the time of Omicron. They explain what you can do to maximize your protection against the highly transmissible variant.
- The difference between natural immunity and vaccine mediated immunity.
- A continuing debate over your natural immunity after getting COVID versus your immunity from receiving the vaccine.
MONICA GANDHI: The question about natural versus vaccination immunity is an important one. The CDC showed that up to the Delta surge, no doubt, that natural immunity is likely as protective or more protective even than from a two-dose vaccines. That's what they showed a big CDC MMWR paper.
SHANE CROTTY: There have been a series of studies that are good, of really the epidemiological data of do people have protective immunity. And the answer has been yes, they do have immune memory. Their immune system does remember that infection for a significant period of time. Now that's up to the point of Omicron.
MONICA GANDHI: That up til Omicron, essentially natural immunity or two-dose vaccines we're looking neck and neck. But what happened during the Omicron surge is in a way, neither one of them protected you against mild infections.
Hence we've got three reasons why vaccines are preferred. One is you didn't get to have get sick to then get immunity. So it's just safer. Second is that in a way, there is more reliability to a vaccine because you know the dose. They chose a dose that elicited a high immune response in all individuals in that study.
And what happens with natural infection is if you have mild infection, you may not mount the strong cellular immune response that you need to fight it in the future. If you had more severe disease, you likely did fight it. So it kind of levels the field to get a vaccine even after natural infection, maybe just one dose. That's what's called hybrid immunity.
And this hybrid immunity seems to be the Teflon or the super immunity, yeah, that really helps our immune systems fight it off. And so even if you've been actually infected, I really would recommend at least one dose of the vaccine.
SHANE CROTTY: To the best of my ability to guesstimate and use the available data, how we would basically rank people in terms of their immunity, both in terms of prevention of infection and in terms of prevention of hospitalization. And so it probably goes hybrid immunity, in either order, vaccination, and then infection, or infection and then vaccination.
Data by tons of labs shows that those people make really broad neutralizing antibodies. Their antibodies recognize every possible variant and even distant viral species. But. They also make really high levels of those antibodies. Then triple dose vaccine.
It's pretty amazing. Three doses of the same vaccine, which is just against the ancestral strain, your immune system is so clever, it's seeing that old version of the spike protein basically, and the first two times it sees it, it makes neutralizing antibodies against the ancestral strain and a couple of variants, but not Omicron.
But just seeing that same vaccine, a third time, and now you make neutralizing antibodies against Omicron. Triple vax is really very impressive evidence of your immune system being clever and being able to neutralize Omicron.
Then two dose of vaccine and then infection alone. Omicron's looking so different from the other variants, that just infection alone might not be giving you great antibodies against the other variants because it looks so different.
What we do know and have a high confidence in is if you've been infected and then you get vaccinated, you have fantastic immunity against everything we know of. And so there's really no downside. There's just upsides to going out and getting vaccinated.