London Daily

Focus on the big picture.
Thursday, Oct 09, 2025

Covid: Double vaccinated can still spread virus at home

Covid: Double vaccinated can still spread virus at home

Double jabbed people are catching Covid and passing it on to those they live with, warn experts who have studied UK household cases.

Individuals who have had two vaccine doses can be just as infectious as those who have not been jabbed.

Even if they have no or few symptoms, the chance of them transmitting the virus to other unvaccinated housemates is about two in five, or 38%.

This drops to one in four, or 25%, if housemates are also fully vaccinated.

The Lancet Infectious Diseases work shows why getting even more people vaccinated and protected is important, they say.

Unvaccinated people cannot rely on those around them being jabbed to remove their risk of getting infected, they warn.

Vaccines do an excellent job of preventing serious Covid illness and deaths, but are less good at stopping infections, particularly since the emergence of the more infectious Delta variant which is dominant in the UK.
And over time, the protection offered by vaccines wanes and needs boosting with further doses.


Since households are where most Covid transmission occurs, making sure every member who is eligible for a vaccine has had one and is up to date with their doses makes sense, say experts.

According to the study, which ran from September 2020 to September 2021 and included 440 households in London and Bolton doing PCR Covid tests:

* People who are double jabbed have a lower, but still appreciable, risk of becoming infected with the Delta variant compared with unvaccinated people

* They also appear to be just as infectious

* Vaccinated people clear the infection more quickly, but their peak viral load - when people are most infectious - is similar to that seen in unvaccinated people

* This may explain why they can still readily pass on the virus in household settings

Prof Ajit Lalvani, of Imperial College London, UK, who co-led the study, said: "The ongoing transmission we are seeing between vaccinated people makes it essential for unvaccinated people to get vaccinated to protect themselves from acquiring infection and severe Covid-19, especially as more people will be spending time inside in close proximity during the winter months.

"We found that susceptibility to infection increased already within a few months after the second vaccine dose - so those eligible for booster shots should get them promptly."

Co-lead Dr Anika Singanayagam, also from Imperial, said: "Our findings provide important insights into the effect of vaccination in the face of new variants, and specifically, why the Delta variant is continuing to cause high Covid case numbers around the world, even in countries with high vaccination rates.

"Continued public health and social measures to curb transmission - such as mask wearing, social distancing, and testing - thus remain important, even in vaccinated individuals."

Newsletter

Related Articles

0:00
0:00
Close
France: Less Than a Month After His Appointment, the New French Prime Minister Resigns
Hungarian Prime Minister Viktor Orbán stated that Hungary will not adopt the euro because the European Union is falling apart.
Sarah Mullally Becomes First Woman Appointed Archbishop of Canterbury
Mayor in western Germany in intensive care after stabbing
Australian government pays Deloitte nearly half a million dollars for a report built on fabricated quotes, fake citations, and AI-generated nonsense.
US Prosecutors Gained Legal Approval to Hack Telegram Servers
Macron Faces Intensifying Pressure to Resign or Trigger New Elections Amid France’s Political Turmoil
Standard Chartered Names Roberto Hoornweg as Sole Head of Corporate & Investment Banking
UK Asylum Housing Firm Faces Backlash Over £187 Million Profits and Poor Living Conditions
UK Police Crack Major Gang in Smuggling of up to 40,000 Stolen Phones to China
BYD’s UK Sales Soar Nearly Nine-Fold, Making Britain Its Biggest Market Outside China
Trump Proposes Farm Bailout from Tariff Revenues Amid Backlash from Other Industries
FIFA Accuses Malaysia of Forging Citizenship Documents, Suspends Seven Footballers
Latvia to Bar Tourist and Occasional Buses to Russia and Belarus Until 2026
A Dollar Coin Featuring Trump’s Portrait Expected to Be Issued Next Year
Australia Orders X to Block Murder Videos, Citing Online Safety and Public Exposure
Three Scientists Awarded Nobel Prize in Medicine for Discovery of Immune Self-Tolerance Mechanism
OpenAI and AMD Forge Landmark AI-Chip Alliance with Equity Option
Munich Airport Reopens After Second Drone Shutdown
France Names New Government Amid Political Crisis
Trump Stands Firm in Shutdown Showdown and Declares War on Drug Cartels — Turning Crisis into Opportunity
Surge of U.S. Billionaires Transforms London’s Peninsula Apartments into Ultra-Luxury Stronghold
Pro Europe and Anti-War Babiš Poised to Return to Power After Czech Parliamentary Vote
Jeff Bezos Calls AI Surge a ‘Good’ Bubble, Urges Focus on Lasting Innovation
Japan’s Ruling Party Chooses Sanae Takaichi, Clearing Path to First Female Prime Minister
Sean ‘Diddy’ Combs Sentenced to Fifty Months in Prison Following Prostitution Conviction
Taylor Swift’s ‘Showgirl’ Launch Extends Billion-Dollar Empire
Trump Administration Launches “TrumpRx” Plan to Enable Direct Drug Sales at Deep Discounts
Trump Announces Intention to Impose 100 Percent Tariff on Foreign-Made Films
Altman Says GPT-5 Already Outpaces Him, Warns AI Could Automate 40% of Work
Singapore and Hong Kong Vie to Dominate Asia’s Rising Gold Trade
Trump Organization Teams with Saudi Developer on $1 Billion Trump Plaza in Jeddah
Manhattan Sees Surge in Office-to-Housing Conversions, Highest Since 2008
Switzerland and U.S. Issue Joint Assurance Against Currency Manipulation
Electronic Arts to Be Taken Private in Historic $55 Billion Buyout
Thomas Jacob Sanford Named as Suspect in Deadly Michigan Church Shooting and Arson
Russian Research Vessel 'Yantar' Tracked Mapping Europe’s Subsea Cables, Raising Security Alarms
New York Man Arrested After On-Air Confession to 2017 Parents’ Murders
U.S. Defense Chief Orders Sudden Summit of Hundreds of Generals and Admirals
Global Cruise Industry Posts Dramatic Comeback with 34.6 Million Passengers in 2024
Trump Claims FBI Planted 274 Agents at Capitol Riot, Citing Unverified Reports
India: Internet Suspended in Bareilly Amid Communal Clashes Between Muslims and Hindus
Supreme Court Extends Freeze on Nearly $5 Billion in U.S. Foreign Aid at Trump’s Request
Archaeologists Recover Statues and Temples from 2,000-Year-Old Sunken City off Alexandria
China Deploys 2,000 Workers to Spain to Build Major EV Battery Factory, Raising European Dependence
Speed Takes Over: How Drive-Through Coffee Chains Are Rewriting U.S. Coffee Culture
U.S. Demands Brussels Scrutinize Digital Rules to Prevent Bias Against American Tech
Ringo Starr Champions Enduring Beatles Legacy While Debuting Las Vegas Art Show
Private Equity’s Fundraising Surge Triggers Concern of European Market Shake-Out
Colombian President Petro Vows to Mobilize Volunteers for Gaza and Joins List of Fighters
×