A: The OG Omicron variant doesn’t seem to produce great cross-protection against other variants. BUT, if you were vaccinated + infected, the protection is MUCH higher.
Omicron is spawning a lot of new “sub-variants,” no doubt thanks to the millions of chances it’s had to replicate and win the mutation lottery.
Two sub-variants of Omicron that are quickly becoming more common are BA.2.12.2, first detected in New York State, and BA.4 and BA.5, currently spreading in South Africa. These variants are currently contributing to rising cases in both the U.S. and South Africa.Recent studies looked at how well blood from people infected with the OG Omicron variant (BA.1) could neutralize these newer subvariants (in a lab dish, not real life).
As expected, blood from people infected with Omicron BA.1 could neutralize BA.1 quite well. BUT-their ability to neutralize BA.2.12.2, BA.4 and BA.5 dropped A LOT, to quite low levels.
For people who had been vaccinated prior to their infection however, neutralization dropped a lot less—with about 5 times the neutralization potency against the new variants compared to those who weren’t vaccinated before infection.
This was consistent with a previous study showing that blood from those infected with BA.1 was not very effective at neutralizing older variants such as Delta, but if vaccinated prior to the BA.1 infection the protection was MUCH higher (see green vs. purple levels in figures below).
Original Omicron/BA.1 infections *by themselves* don’t seem to induce strong immunity against other variants.
SO…if you’re unvaccinated and counting on your Omicron infection as an “natural” vaccine, the news is not good.
In contrast, a BA.1 infection *after* vaccination shows much higher levels of neutralizing antibodies against both previous and newly developing variants.
While hybrid immunity typically means infection AFTER vaccination, vaccination after infection produces similar boosts in antibody response.
So, it’s never too late to significantly boost your protection against the variants that are coming down the pike—get vaccinated AND boosted if you are eligible.
Those Nerdy Girls
“If you’ve had omicron before, are you safe from infection by the new variants?”
Source, Figure 1: “Omicron infection enhances Delta antibody immunity in vaccinated persons.”
Source: Figure 2: “Omicron sub-lineages BA.4/BA.5 escape BA.1 infection elicited neutralizing immunity.”
“BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection.”
“Should I get a booster shot if I’ve already had COVID-19?”