Saudi Press

Saudi Arabia and the world
Saturday, Jul 05, 2025

Pfizer Jab Provides Less Immunity To Omicron Than Other Variants

Pfizer Jab Provides Less Immunity To Omicron Than Other Variants

Researchers at the Africa Health Research Institute in Durban, South Africa, found omicron resulted in about a 40-fold reduction in levels of neutralizing antibodies produced by people who had received two doses of the Pfizer-BioNTech SE shot.

Pfizer Inc.'s vaccine provides less immunity to the omicron variant than to other major versions of Covid-19, according to laboratory experiments that still indicated a third dose may help stop the highly mutated strain.

Researchers at the Africa Health Research Institute in Durban, South Africa, found omicron resulted in about a 40-fold reduction in levels of neutralizing antibodies produced by people who had received two doses of the Pfizer-BioNTech SE shot, compared with the strain detected in China almost two years ago.

The loss of immune protection is "robust, but not complete," Alex Sigal, head of research at the laboratory, said in an online presentation of the first reported experiments gauging the effectiveness of the vaccine against the new variant.

"There will be more breakthrough" of vaccine-induced immunity, Sigal said. "A good booster probably would decrease your chance of infection, especially severe infection leading to more severe disease. People who haven't had a booster should get one, and people who have been previously infected should be vaccinated."

Representatives for Pfizer and BioNTech, makers of the first Covid vaccine cleared in the U.S., didn't immediately respond to a request for comment. The study may add to the debate over whether tweaked, omicron-targeted vaccines will be needed soon to continue effectively fighting the pandemic. Moderna Inc. President Stephen Hoge has said there's a risk that existing vaccines will be less effective against the strain, although U.S. medical adviser Anthony Fauci said the severity of illness caused by the variant may be limited.

Omicron's rapid spread in South Africa has raised concern that the immune protection from vaccination or a previous bout of Covid-19 may be insufficient to stop reinfections or stem a fresh wave of cases and hospitalizations. The World Health Organization has warned omicron could fuel surges with "severe consequences" amid signs that it makes the coronavirus more transmissible.

Cautious Optimism


Still, the jump in cases in South Africa following omicron's emergence hasn't overwhelmed hospitals so far, prompting some cautious optimism that the new strain may cause mostly mild illness.

Since South Africa announced the discovery of omicron on Nov. 25, about 450 researchers globally have been working to isolate the variant from patient specimens, grow it in labs, verify its genomic sequence, and establish methods to test it in blood-plasma samples, according to the WHO.

The work in Sigal's lab involved testing 14 blood plasma samples collected from a dozen people who had been given a second Pfizer-BioNTech shot about a month earlier to gauge the concentration of antibodies needed to neutralize, or block, the virus. Levels of neutralizing antibodies against omicron were notably higher in a subset of participants who had a bout of Covid about a year earlier, Sigal said.

That's "promising," said John Wherry, director of the institute for immunology at the University of Pennsylvania's Perelman School of Medicine. It likely means an additional dose of the currently available vaccines would boost levels of neutralizing antibodies to omicron, though more data are needed to confirm that, he said.

The results are preliminary and exact levels of immune escape may change, Sigal said. The results, along with those from other labs studying the strain, will help determine whether existing Covid vaccines need to be altered to protect against omicron.

Sigal's laboratory was the first to isolate the beta variant, a strain of the coronavirus that was identified in South Africa in late 2020. He noted that omicron escapes antibody neutralization more readily than beta, which had been considered the most immune evasive of the variants of concern detected previously.

Newsletter

Related Articles

Saudi Press
0:00
0:00
Close
AI Raises Alarms Over Long-Term Job Security
Saudi Arabia Maintains Ties with Iran Despite Israel Conflict
Russia Formally Recognizes Taliban Government in Afghanistan
Mediators Edge Closer to Israel-Hamas Ceasefire Agreement
Emirates Airline Expands Market Share with New $20 Million Campaign
House Oversight Committee Subpoenas Former Jill Biden Aide Amid Investigation into Alleged Concealment of President Biden's Cognitive Health
Amazon Reaches Major Automation Milestone with Over One Million Robots
Meta Announces Formation of Ambitious AI Unit, Meta Superintelligence Labs
China Unveils Miniature Insect-Like Surveillance Drone
Marc Marquez Claims Victory at Dutch Grand Prix Amidst Family Misfortune
Iran Executes Alleged Israeli Spies and Arrests Hundreds Amid Post-War Crackdown
Trump Asserts Readiness for Further Strikes on Iran Amid Nuclear Tensions
Iran's Parliament Votes to Suspend Cooperation with Nuclear Watchdog
Trump Announces Upcoming US-Iran Meeting Amid Controversial Airstrikes
Trump Moves to Reshape Middle East Following Israel-Iran Conflict
NATO Leaders Endorse Plan for Increased Defence Spending
U.S. Crude Oil Prices Drop Below $65 Amid Market Volatility
Explosions Rock Doha as Iranian Missiles Target Qatar
“You Have 12 Hours to Flee”: Israeli Threat Campaign Targets Surviving Iranian Officials
Oman Set to Introduce Personal Income Tax, First in Gulf
Germany and Italy Under Pressure to Repatriate $245bn of Gold from US Vaults
Iran Intensifies Crackdown on Alleged Mossad Operatives After Sabotage Claims
Trump Praises Iran’s ‘Very Weak’ Response After U.S. Strikes and Presses Israel to Pursue Peace
WATCH: Israeli forces show the aftermath of a massive airstrike at Iran's Isfahan nuclear site
We have new information and breaking details to share about what is shaping up to be a historic air campaign tonight
Six Massive Bombs Dropped on Fordow; Trump: 'A Historic Moment for the U.S., Israel, and the World'
Fordow: Deeply Buried Iranian Enrichment Site in U.S.–Israel Crosshairs
United States Conducts Precision Strikes on Iran’s Nuclear Sites
US strikes Iran nuclear sites, Trump says
Pakistan to nominate Trump for Nobel Peace Prize.
Israel Confirms Assassination of Quds Force Commander in Tehran
16 Billion Login Credentials Leaked in Unprecedented Cybersecurity Breach
Senate hearing on who was 'really running' Biden White House kicks off
G7 Leaders Fail to Reach Consensus on Key Global Issues
Mass exodus in Tehran as millions try to flee following Trump’s evacuation order
Iranian Military Officers Reportedly Seek Contact with Reza Pahlavi, Signal Intent to Defect
Vietnam Emerges as Luxury Yacht Destination for Ultra‑Rich
China's Iranian Oil Imports Face Disruption Amid Escalating Middle East Tensions
Trump Demands Iran's Unconditional Surrender Amid Escalating Conflict
Israeli Airstrike Targets Iranian State TV in Central Tehran
President Trump is leaving the G7 summit early and has ordered the National Security Council to the Situation Room
Netanyahu Signals Potential Regime Change in Iran
Analysts Warn Iran May Resort to Unconventional Warfare
Iranian Regime Faces Existential Threat Amid Conflict
Energy Infrastructure Becomes War Zone in Middle East
Iran Conducts Ballistic Missile Launches Amid Heightened Tensions with Israel
Iran Signals Openness to Nuclear Negotiations Amid Ongoing Regional Tensions
Shock Within Iran’s Leadership: Khamenei’s Failed Plan to Launch 1,000 Missiles Against Israel
Trump's Anti-War Stance Tested Amid Israel-Iran Conflict
UK Deploys Jets to Middle East Amid Rising Tensions
×