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Antibodies are not vaccines. Antibodies bind to an antigen (virus component in this case) to get the immune system to attack and destroy the antigen and whatev
by harshreality 2y ago
Antibodies are not vaccines. Antibodies bind to an antigen (virus component in this case) to get the immune system to attack and destroy the antigen and whatever it's attached to.
A vaccine causes the patient to develop specific immunity (fast reaction to a specific antigen) by introducing (usually injecting) a large amount of an antigen. That prompts the immune system to react by developing B-cells that produce their own antibodies to the antigen. It turns the body into its own antibody factory to deal with whatever you injected, but that takes time.
Injecting antibodies, as in this study, bypasses the natural (slow) specific immunity generation process. Antibodies are created some other way (in a lab, or in some other animal) and then directly injected. It's done for serious diseases or dangerous toxins or immuno-compromised individuals, when waiting for the patient to develop their own specific immunity is too slow or dangerous.
Critically, a vaccine allows the body to maintain the ability to fight off similar-enough infections for a while, but usually takes weeks or more to reach near full effect, sometimes requiring multiple shots for better effectiveness. If you're trying to treat an infection you think you might already have or will get in the next few days, vaccines only work if the progression of the disease is very slow, as in rabies which takes something like 1-2 months to make it into the CNS.
Injecting antibodies is a one-shot treatment that must be repeated until the virus (or toxin or other bad thing) is gone. It's commonly done for toxins (spider or snake venoms), or sometimes for severe diseases (ebola, tetanus), but sars-cov-2 has so much attention that now they're doing it for that too. In patients who aren't immunocompromised, antibody treatments for less-lethal infections give their immune systems more time to generate their own antibodies without developing severe symptoms.
The similarity in the two approaches is that they both ultimately involve antibodies binding to coronavirus proteins. The difference is in where those antibodies come from, and whether the body can produce more at will (vaccine --[time]--> natural immunity), or whether you have to keep injecting them (antibody treatments).
That's only a rough approximation. The immune system is very complicated. Wikipedia, or a book on molecular biology or immunology, will go into a lot more detail.
- ggm 2y agoSo it could be given eg daily prophylactically to health workers, and important functional workers during a breakout pandemic to ensure they can continue to work, with very high likelihood of exposure. If it meant less biohazard cosplay (really? it works but it's such a high burden to get right and its exhausting from what health workers say) I'd say it's worth exploring on those grounds alone. Anything to keep health and vital service staff functional during the bad times.
- harshreality 2y agoMaybe there's a hypothetical where there's somehow rapid availability of specific antibodies, but no opportunity to vaccinate healthcare workers ahead of time, and it somehow makes sense to rely on antibody injections instead of PPE ("biohazard cosplay"). Here are some reasons why it probably doesn't. Getting treated with antibodies don't mean you're asymptomatic or that you'll feel well. It only means you'll have less severe symptoms. You'd have healthcare workers walking around sick, spreading the very disease they're trying to treat others for. Or taking up a hospital or clinic bed, not treating patients, using up limited healthcare resources — which, for the duration of their illness, is a worse outcome for their patients than if the healthcare workers weren't there at all. It's expensive. There's no economy of scale for an unusual disease outbreak. That applies to both antibody and vaccine stockpiles. If the disease is minor (like COVID-19 usually is for otherwise healthy individuals), healthcare workers might be willing to take a chance to avoid the hassle of PPE, but would their employer (such as a hospital, or MSF)? They're the ones who have to pay for antibody treatment if their healthcare employees get sick. They're the ones who have medical ethicists looking out for both the well-being of the frontline healthcare workers and patients. If the disease has a significant mortality rate, availability of a specific antibody treatment, even if it's stocked and instantly available, wouldn't motivate anyone to go without PPE. Nor would getting vaccinated. They're not guarantees of survival, and preventing healthcare workers from getting sick is more important than treating patients.
- ggm 2y agoYea I hadn't really thought it through. I went straight to a hallelujah outcome when most things "in mice" don't wash through, and are expensive. Disposable PPE is less expensive and we know it works. Sweaty and tiring, but works.
- duskwuff 2y agoNot to mention, PPE protects you against diseases which aren't COVID-19 - the common cold, influenza, tuberculosis... health care workers are always going to be safer (and keep their patients safer!) by masking up.
- Galatians4_16 2y agoAntibodies are just one re-definition away from becoming vaccines, lol