Early data suggests fourth dose of vaccine may not boost protection against Omicron

key takeaways

  • Early results from an Israeli clinical trial pitting a COVID-19 vaccine booster against the Omicron variant were not reassuring.
  • While trial participants saw an increase in antibodies to COVID-19, the booster may not help prevent people from contracting the Omicron variant.
  • A second booster is underway in Israel, but not yet available in the rest of the world.

A second booster dose of Pfizer’s or Moderna’s COVID-19 vaccine looks hopeless against breakthrough infections caused by the Omicron variant, based on preliminary results from two clinical trials in Israel.

On January 17, Gili Regev-Yochay, MD, MS, MPH, director of infectious diseases at Sheba Medical Center in Tel Aviv, Israel, and head of the study, briefed reporters on the results of an earlier unpublished study.

Where do the COVID variants come from?

test booster

According to Regev-Yochay, the trials are designed to “examine the efficacy of the vaccine and compare the results of antibody levels and defense against Omicron.”

The trials included 274 people working at Sheba Medical Center in Tel Aviv. All participants had previously received a total of 3 doses of Pfizer’s COVID vaccine. In the trial, 154 people received an additional dose of Pfizer as a booster, and another 120 received a booster of Moderna’s COVID vaccine.

According to Regev-Yochay, “The rise in antibody levels we saw with Moderna and Pfizer was slightly higher than what we saw after the third vaccine.”

However, as more people were vaccinated with Omicron (even with an increase in antibodies), “a fourth vaccine only provides partial defense against the virus.”

Regev-Yochay concluded that while these vaccines were effective against previous variants, they “provided less protection than Omicron.”

Still, Regev-Yochay acknowledged in the briefing that a booster might be a good idea for high-risk groups.

How vaccine makers are responding to Omicron mutations

Fourth dose

The Israeli government isn’t waiting for clinical trials to wrap up to act – the country has already started giving some citizens a fourth dose of the vaccine.

The Israeli Ministry of Health recently authorized a fourth dose of the vaccine for Israelis 60 years of age and older, immunocompromised individuals, and healthcare workers.according to the age of Israel, As of January 16, more than 500,000 Israelis had received the fourth vaccine.

Still, COVID cases in Israel continue to rise. Reuters The seven-day average of new COVID cases in Israel was 3,290 infections per 100,000 people, the highest level since the pandemic began, reported Jan. 18. And it’s still rising.

Extra doses and boosters

The COVID vaccine booster is given to people who have completed an initial series of doses and only need a “boost” of immunity, which naturally wanes over time.

An additional dose of the vaccine is given to people who may not respond well to the first dose (for example, people with compromised immune systems).

Here’s the difference between a COVID-19 booster shot and a third dose

Who needs a second booster?

While disappointing, the Sheba Medical Center trial data will inform the conversation around whether Americans need a second booster.

In the U.S., Anthony Fauci, MD, has repeatedly said that the government will pay close attention to Israeli data on second-generation boosters. As of Jan. 18, Fauci had not commented on the latest findings from the Israel trial.

Who takes 4 doses in the US?

Currently, the Centers for Disease Control and Prevention (CDC) recommends that immunocompromised people receive three primary doses of Pfizer’s or Moderna’s vaccine, plus a booster dose at least five months after the last dose of their primary series.

For immunocompromised people who get one dose of J&J vaccine, current CDC guidance is to get a booster dose—preferably a Pfizer or Moderna vaccine, not a second J&J vaccine—at least two months after the first dose.

CDC recommends Pfizer and Moderna vaccines over Johnson & Johnson

“There are some fundamental flaws in people’s understanding of how vaccines work,” Aaron Glatt, M.D., chief of infectious diseases in South Nassau at Mount Sinai, told VigorTip. “Antibody levels are the wrong way to assess whether a vaccine is working. The only real way is to assess the clinical severity of the disease.”

At this point, Glatt said, if someone could show “more severe clinical disease in patients who received only three doses compared to patients who received an additional fourth dose, they would only recommend a fourth dose. Since there is currently no evidence to suggest that In this case, I usually don’t recommend people get a fourth dose.”

The NIH is funding a second booster injection clinical trial in the United States, according to a spokesperson for the National Institutes of Health (NIH). The trial is currently enrolling kidney and liver transplant recipients who received two to four doses of the COVID-19 mRNA vaccine and did not develop an antibody response.

The study will investigate whether an additional booster dose alone or in combination with reducing immunosuppressive drugs increases COVID antibodies in these patients.

Will we have a vaccine for Omicron?

What works with Omicron variants? Regev-Yochay told VigorTip that an Omicron-specific vaccine may be needed.

January 18, Statistical News If the U.S. Food and Drug Administration (FDA) decides to update its COVID vaccine to be more effective against variants, it may coordinate with international partners, as it does with its annual flu vaccine, the report said.

what does this mean to you

Early data from clinical trials in Israel suggest that a fourth dose of the COVID vaccine may not be enough to prevent you from getting Omicron. However, getting your initial vaccine series is still critical to protecting yourself and others.

That said, people at high risk, such as those with compromised immune systems, may be able to get a fourth dose of the COVID vaccine.

The information in this article is current as of the date listed, which means that you may have updated information as you read this article.For the latest updates on COVID-19, visit our coronavirus news page.