Still Life with Armor, Shield, Halberd, Sword, Leather Jacket, and Drum

Lost in the Details: Obesity, Antibodies, and Immunity

We’re hearing a lot about antibodies and immunity to COVID-19 and its new variants right now. But unfortunately, a lot of it is speculation that does more to confuse our response than to make us smarter. Omicron significantly reduces Covid antibody protection in small study of Pfizer vaccine recipients, says a typical headline. This is very similar to research that focuses on the antibody response to vaccines in people with obesity. Scientifically, it’s interesting. But it only tells a small part of the story about how vaccines protect us from COVID-19.

Writing in The Conversation, Mick Bailey and Nicholas John Timpson explain:

“Lower levels of neutralising antibodies doesn’t necessarily mean people are completely exposed. Past studies have also found that many people with low levels of antibodies do still appear to be sufficiently protected, particularly against severe disease, even with the newer variants like delta.”

Immunity Comes from More Than Neutralizing Antibodies

Neutralizing antibodies form the first line of defense against infection with COVID-19. They are also easy to measure. So that’s why the first reports about omicron came with lots of worrisome factoids about the effectiveness of our antibodies against it. Those factoids were convenient to serve up. But they also served to confuse the issue of how effective vaccines will be for protecting us from this variant.

This is because vaccines do more than just help us make antibodies. Again, Baily and Timpson explain:

“Neutralising antibodies that attack and nullify the virus are just part of the immune response. There are also binding antibodies, which attach to the virus or to infected cells to flag them to other immune cells for destruction, and T cells and memory B cells, which can attack the virus directly and produce more antibodies to fight it.”

Vaccines Remain Helpful

We’re still in the early days of the spread of omicron, but just about all of the cases in vaccinated individuals have been mild. In a recent CDC report, only one of 43 persons with this variant required a hospital stay (2 days).

Even if omicron is better at spreading in the population because it can evade our neutralizing antibodies, vaccines can still be helpful because of the robust immune protection they provide against severe disease. Andrew Redd is a virologist at NIAID. Referring to his research (here and here) on mutations and their effects on T cell immunity against COVID, he said:

“It suggests that T cell responses remain largely intact and should remain largely intact against omicron.”

Familiar, Confusing Speculation

The confusion about vaccines, antibodies, and protection from COVID-19 is familiar. Even before we had vaccines for COVID-19, we had speculation that they would not work well for people with obesity. The speculation was wrong, but that didn’t stop it.

Research on antibody responses to the COVID vaccine and how it varies for different mutations of the virus and for people with different conditions will continue. In obesity, it deserves attention. Alexis Elias Malavazos and colleagues pointed this out in a recent paper.

But let’s remember. The protection against COVID-19 from vaccines comes from more than just antibodies. Details about antibody responses are nice to know. However, the big picture of how well we’re protected is what matters most.

We have two great tools for protecting ourselves from this virus: masks and vaccines. Let’s use them well.

Click here for more from Bailey and Timpson, here for more on T cells and the omicron variant. For more on the effectiveness of COVID vaccines in people with obesity, click here.

Still Life with Armor, Shield, Halberd, Sword, Leather Jacket, and Drum, painting by Gerrit Dou / WikiArt

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


December 13, 2021