A single dose of the Pfizer coronavirus vaccine is “highly protective” after three weeks, according to a study.
Researchers at the University of East Anglia (UEA) said the coronavirus vaccine developed by Pfizer and BioNTech was still effective after 21 days without a ‘top up’ dose in the recommended time frame.
It comes after a study found that the Oxford coronavirus vaccine offers protection of 76 per cent up to 12 weeks after a single dose and may reduce transmission by 67 per cent.
The UEA study of the Pfizer jab, which has not yet been peer-reviewed, looked at data from Israel where the vaccine has been rolled out. Scientists found the vaccine becomes 90 per cent effective after 21 days – supporting UK plans to delay the timing of a second jab.
While it is not yet known how long immunity lasted beyond 21 days without a second dose, researchers believe it is “unlikely” to majorly decline during the following nine weeks.
But scientists warned people’s risk of infection doubled in the first eight days after the Pfizer vaccine jab, citing people becoming less cautious as a possible cause.
“A recent non peer-reviewed pre-print paper based on Israel’s experience looked at data from 500,000 people who had been given the Pfizer vaccine. It reported that a single dose may not provide adequate protection,” said lead researcher Professor Paul Hunter, from UEA’s Norwich Medical School.
“But we saw a number of flaws in how they looked at the data including the fact that they did not attempt to estimate the effectiveness of the vaccine from day 18 onwards. This would have given a better indication of how effective a single dose of the vaccine could be if the second dose was delayed by up to 12 weeks.”
Researchers analysed data to see the impact of the Israeli vaccination programme on case numbers, and went on to estimate vaccine effectiveness over time. They found that after the initial vaccination case numbers increased for eight days before declining “to low levels” by day 21.
“Surprisingly, the daily incidence of cases increased strongly after vaccination till about day eight – approximately doubling,” Prof Hunter said.
Image Credit: Envato/Amanda Scott
Post by Amanda Scott, NA CEO. Follow her on twitter @tantriclens
Thanks to Heinz V. Hoenen. Follow him on twitter: @HeinzVHoenen

News
3D-printed implant offers a potential new route to repair spinal cord injuries
A research team at RCSI University of Medicine and Health Sciences has developed a 3-D printed implant to deliver electrical stimulation to injured areas of the spinal cord, offering a potential new route to [...]
Nanocrystals Carrying Radioisotopes Offer New Hope for Cancer Treatment
The Science Scientists have developed tiny nanocrystal particles made up of isotopes of the elements lanthanum, vanadium, and oxygen for use in treating cancer. These crystals are smaller than many microbes and can carry isotopes of [...]
New Once-a-Week Shot Promises Life-Changing Relief for Parkinson’s Patients
A once-a-week shot from Australian scientists could spare people with Parkinson’s the grind of taking pills several times a day. The tiny, biodegradable gel sits under the skin and releases steady doses of two [...]
Weekly injectable drug offers hope for Parkinson’s patients
A new weekly injectable drug could transform the lives of more than eight million people living with Parkinson's disease, potentially replacing the need for multiple daily tablets. Scientists from the University of South Australia [...]
Most Plastic in the Ocean Is Invisible—And Deadly
Nanoplastics—particles smaller than a human hair—can pass through cell walls and enter the food web. New research suggest 27 million metric tons of nanoplastics are spread across just the top layer of the North [...]
Repurposed drugs could calm the immune system’s response to nanomedicine
An international study led by researchers at the University of Colorado Anschutz Medical Campus has identified a promising strategy to enhance the safety of nanomedicines, advanced therapies often used in cancer and vaccine treatments, [...]
Nano-Enhanced Hydrogel Strategies for Cartilage Repair
A recent article in Engineering describes the development of a protein-based nanocomposite hydrogel designed to deliver two therapeutic agents—dexamethasone (Dex) and kartogenin (KGN)—to support cartilage repair. The hydrogel is engineered to modulate immune responses and promote [...]
New Cancer Drug Blocks Tumors Without Debilitating Side Effects
A new drug targets RAS-PI3Kα pathways without harmful side effects. It was developed using high-performance computing and AI. A new cancer drug candidate, developed through a collaboration between Lawrence Livermore National Laboratory (LLNL), BridgeBio Oncology [...]
Scientists Are Pretty Close to Replicating the First Thing That Ever Lived
For 400 million years, a leading hypothesis claims, Earth was an “RNA World,” meaning that life must’ve first replicated from RNA before the arrival of proteins and DNA. Unfortunately, scientists have failed to find [...]
Why ‘Peniaphobia’ Is Exploding Among Young People (And Why We Should Be Concerned)
An insidious illness is taking hold among a growing proportion of young people. Little known to the general public, peniaphobia—the fear of becoming poor—is gaining ground among teens and young adults. Discover the causes [...]
Team finds flawed data in recent study relevant to coronavirus antiviral development
The COVID pandemic illustrated how urgently we need antiviral medications capable of treating coronavirus infections. To aid this effort, researchers quickly homed in on part of SARS-CoV-2's molecular structure known as the NiRAN domain—an [...]
Drug-Coated Neural Implants Reduce Immune Rejection
Summary: A new study shows that coating neural prosthetic implants with the anti-inflammatory drug dexamethasone helps reduce the body’s immune response and scar tissue formation. This strategy enhances the long-term performance and stability of electrodes [...]
Scientists discover cancer-fighting bacteria that ‘soak up’ forever chemicals in the body
A family of healthy bacteria may help 'soak up' toxic forever chemicals in the body, warding off their cancerous effects. Forever chemicals, also known as PFAS (per- and polyfluoroalkyl substances), are toxic chemicals that [...]
Johns Hopkins Researchers Uncover a New Way To Kill Cancer Cells
A new study reveals that blocking ribosomal RNA production rewires cancer cell behavior and could help treat genetically unstable tumors. Researchers at the Johns Hopkins Kimmel Cancer Center and the Department of Radiation Oncology and Molecular [...]
AI matches doctors in mapping lung tumors for radiation therapy
In radiation therapy, precision can save lives. Oncologists must carefully map the size and location of a tumor before delivering high-dose radiation to destroy cancer cells while sparing healthy tissue. But this process, called [...]
Scientists Finally “See” Key Protein That Controls Inflammation
Researchers used advanced microscopy to uncover important protein structures. For the first time, two important protein structures in the human body are being visualized, thanks in part to cutting-edge technology at the University of [...]