This Is When Your Vaccine Stops Protecting You From Omicron, New Study Says

Researchers were able to measure antibody levels after a third and fourth dose.

If two years of life under the pandemic have proven anything, it's that COVID-19 is an elusive enemy with no shortage of surprises. But even as case counts have risen and fallen as the virus has taken on slightly new forms that affect its transmissibility, highly effective vaccines have helped bring hospitalization and death rates down to much lower levels than during the earliest days of the virus. This was true even for the Omicron variant, which sent the national infection rate to its highest points ever in mid-January and is currently causing infections to rise once again.

READ THIS NEXT: Over 50? Do Not Get a Second Booster If You've Done This, CDC Warns.

Fortunately, research has shown that the rollout of vaccines and their subsequent boosters has helped protect the public from COVID-19, USA Today reports. Data from the Centers for Disease Control and Prevention (CDC) through March 19 of this year found that unvaccinated Americans over the age of five were ten times more likely to die from the virus than those who received both initial shots. And those 12 or older were found to be 20 times more likely to succumb to the virus if they hadn't been vaccinated.

However, time has still proven to be a significant challenge in the fight against COVID-19. Highly contagious new variants have tested the vaccines' efficacy in preventing infection while waning immunity from the original shots has also brought about the need for additional doses. But according to a new study published on May 13 in JAMA Network Open, some boosters may only offer a brief window of protection from the rapidly spreading Omicron variant, Forbes reports.

The latest research considered 128 patients who had received at least both initial shots of the Pfizer vaccine and some who had received the third booster dose. Blood tests were taken from each to examine antibody levels, which can help measure how protected someone is from infection from the virus or severe illness. Results found that levels of specific "neutralizing" antibodies that protect against the Omicron variant fell "rapidly" compared to those effective against the Delta variant and original strain, dropping from 76 percent four weeks after the second initial dose to 53 percent eight to ten weeks later and 19 percent at the 12 to 14-week mark.

Results also showed that a booster shot shored up antibody levels, increasing them nearly 21-fold three weeks after they were administered and 8-fold at the four-week mark compared to the second initial dose, Forbes reports. But even though most people showed a significant immune response through eight weeks, results also found protection quickly dropped off after the third dose, showing that Omicron-specific antibody levels dropped 5.4-fold between the three-to-eight week window following the shot. Comparatively, antibody levels for the original COVID-19 virus and the Delta variant dropped 4.9-fold and 5.6-fold over the same period, respectively.

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The researchers conclude their results suggest older or immunocompromised people will likely need more boosters shots to shore up their protection from the virus in the future. However, the findings also shed more light on how COVID-19 boosters will be used in the general public beyond the third dose and how efficient it would be to re-administer them regularly. While the neutralizing antibodies measured in the study represent one part of the immune defense mounted by the body, other elements such as T cells could provide long-term protection against serious illness, which is essentially the actual function of a vaccine, Forbes reports.

Still, some other recent research supports using additional shots to protect from the virus. Preliminary data from a study of just over 2,600 patients hospitalized with severe COVID across 14 medical centers in Israel during Omicron's surge shows that those given a fourth shot had a 49 percent lower chance of having a poorer outcome compared to those who had received their third booster dose five months before their COVID diagnosis, according to GlobalData Healthcare.

"While the study design made it difficult to determine if the additional booster dose reduces the severity of COVID-19, it does suggest that a fourth dose may improve clinical outcomes and subsequently have the potential to reduce the number of hospitalizations and deaths," the experts wrote. "As such, an additional round of booster vaccinations may be an appropriate response to uphold the current trends that have sparked assertions of an end to the pandemic phase of COVID-19."

Currently, the CDC recommends that anyone 50 or older and those who are moderately to severely immunocompromised are eligible for a fourth shot four months after receiving their first booster dose. Some U.S. officials have warned that supplemental shots could help avoid another surge in cases that some anticipate may arrive this fall.

"We've got to be prepared. And we've got to be prepared with vaccinations, with boosters … that's what I mean when we say we can't leave our guard down. Even though, right at this moment, we're not in the so-called fulminant phase of the outbreak, we are still in the middle of the pandemic," Chief White House COVID adviser Anthony Fauci, MD, said during a May 12 interview with NewsNation's Rush Hour. "There are so many things that we can and should do to make sure that this does not go on."

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Zachary Mack
Zach is a freelance writer specializing in beer, wine, food, spirits, and travel. He is based in Manhattan. Read more
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