A fourth booster dose of the COVID-19 vaccine boosts immune response but may not be enough to ward off Omicron variant, finds the preliminary results of a study conducted in Israel.

With Omicron continuing to rage on, experts have been toying with the idea of allowing a fourth booster dose of the vaccine, especially high risk patients who may not be adequately protected from infections with even 3 doses.

However, preliminary results of a study conducted by the Sheba Medical Center in Israel found that although 4 doses of an mRNA vaccine significantly increased antibody production in the recipients, it's not enough to protect against Omicron.

"We know by now that the level of antibodies needed to protect and not to got infected from Omicron is probably too high for the vaccine, even if it's a good vaccine," Gili Regev-Yochay, director of the Infectious Diseases Unit, was quoted as saying by Reuters.

Here's a quick run down of some key points of the study.

• 154 members of staff at Sheba Medical Center, Israel, were given a second booster dose of the Pfizer vaccine.

• 120 people were given a Moderna booster dose after having received 3 doses of Pfizer COVID vaccine.

• The immune response of these participants was compared to that of people in a control group who didn't receive a fourth shot.

• No further data from the study has been released yet, and the results of the study are let to be peer reviewed and published.

In Israel, a fourth dose of the COVID-19 vaccine is being offered to a select subgroup of elderly and immunocompromised people.

This was done despite there being a lack of evidence to support a need for it. In fact, in an interview with CNBC, Pfizer CEO Albert Bourla, himself said that they didn't know if a fourth dose was needed and that Pfizer would conduct their own studies determine the same.

If the preliminary results of this study re anything to go by, it would indicate that there is in fact no point in administering a fourth dose of the vaccine, as far as protection from the Omicron variant in concerned.

Experts caution that at a time when the world is grappling with a widespread spike in COVID cases, and many countries have started rolling out a 3rd booster dose for its populations, giving out a fourth booster dose in spite of a lack of evidence could lead to a dangerously wasteful trend.

In the meantime, companies like Pfizer and BioNTech, Moderna and India's Gennova Biopharmaceuticals are in the process of developing COVID vaccines specifically for the Omicron variant.

(Written with inputs from Reuters, Times of Israel, and CNBC.)