How well do COVID vaccines and their boosters protect against omicron? What data shows
Time after time, studies show coronavirus vaccines protect most people from severe COVID-19, including hospitalization and death, and that the protection has held up against the many variants that have emerged along the way.
But omicron is testing the vaccines like no coronavirus mutant has before.
In just about three weeks since the variant was first detected in the U.S., omicron has been found in at least 39 states and more than 75 countries, Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said during a Dec. 17 White House COVID-19 briefing.
Omicron outbreaks and fears have canceled Broadway performances in New York City, reissued statewide face mask mandates and returned college students to online classes. Now, models reveal rather grim projections for the next couple of months.
So, how are the vaccines holding up?
Most evidence collected and analyzed so far has come from laboratory experiments, meaning they don’t show how effective the vaccines are in real-world settings. They also only reveal how people respond to vaccines via antibodies, leaving out other important parts of the immune system that play protective roles.
As scientists learn more, a couple of points are clear: Booster shots significantly increase protection against infection and severe disease, and breakthrough cases are possible, even with three doses.
Here’s a breakdown of how each COVID-19 vaccine fares against omicron based on early data.
How well do the Pfizer vaccine and booster protect against omicron?
Experiments on blood samples from people who received two doses of the Pfizer vaccine a month prior found antibody levels decreased 25-fold, on average, when put up against the omicron variant.
The laboratory results suggest two shots may not protect against omicron infection.
Boosters, however, increased antibody levels 25-fold against omicron a month later, similar to levels seen after two doses against the original version of the coronavirus.
Two doses of the Pfizer vaccine may still protect against severe COVID-19, including hospitalization and death, the data suggests; other parts of the immune system that are primed by the vaccine “are not affected by the mutations in the omicron variant,” Pfizer officials said in a news release.
How well do the Moderna vaccine and booster protect against omicron?
A non-peer-reviewed study found antibody levels following two doses of the Moderna vaccine are anywhere between 49 to 84 times lower when put up against omicron compared with the original coronavirus strain.
Again, the results suggest an increased risk of coronavirus infection after complete vaccination.
Moderna officials announced on Dec. 20 that a booster of its vaccine — currently authorized as half the dose of the primary shots (50 micrograms) — increased antibody levels 37-fold a month later.
A booster of the same dose as the primary shots (100 micrograms) increased antibody levels 83-fold.
The company said it’s working on an omicron-specific booster “in case it becomes necessary in the future.”
How well does the Johnson & Johnson vaccine protect against omicron?
Johnson & Johnson officials said on Dec. 16 that they are working on collecting data on how their vaccine fares against the omicron variant.
However, small studies that have yet to be peer reviewed show the single-dose J&J shot provides little to no protection against omicron, multiple news outlets report.
The vaccine recently lost some support from federal health officials, too.
The CDC says it has a “clinical preference” for the Pfizer or Moderna COVID-19 vaccines over the J&J shot after a review of the latest data showed the J&J vaccine prevents fewer COVID-19 hospitalizations, intensive care unit admissions and deaths than the other two shots.
Among primary concerns were the risks associated with the J&J vaccine, including a rare blood clotting condition called “thrombosis with thrombocytopenia syndrome (TTS)” and “Guillain-Barré syndrome (GBS),” which tricks your immune system to attack your body’s nerves.
The agency emphasizes, however, that any vaccine is better than being unvaccinated, and that anyone who doesn’t want a Pfizer or Moderna shot or cannot receive them for medical reasons will still have access to the J&J vaccine.
Studies show a J&J booster shot offers the weakest increase in antibody levels; most expert suggest receiving a Pfizer or Moderna booster.
This story was originally published December 20, 2021 at 4:38 PM with the headline "How well do COVID vaccines and their boosters protect against omicron? What data shows."
