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Covid Boosters Are Backed By Uk Scientists After A Study Found Post Jab Antibody Drops

Since blood tests on hundreds of people demonstrated that protective antibodies can diminish significantly within weeks of second vaccination doses being administered, scientists have approved recommendations for Covid supplements in the autumn.
Antibodies fall after vaccination, which does not necessarily indicate people are more susceptible to disease, but the researchers are concerned that if the declines continue, the vaccines’ effectiveness may be harmed.
Antibodies created by two doses of the Oxford/AstraZeneca and Pfizer/BioNTech vaccines began to decline as early as six weeks after the second shot, in some cases declining by more than 50% over ten weeks, according to the UCL Virus Watch study.
Both vaccines are quite efficient against Covid, according to the researchers, but the findings support plans for a booster campaign this autumn, especially for individuals who were inoculated early and with the Oxford/AstraZeneca vaccine.
Dr Rob Aldridge, an infectious disease epidemiologist at UCL, said, “We know antibody levels start high and drop significantly.”
“We’re afraid that if they continue to decline at the rate we’ve seen, the vaccines’ protective benefits will begin to wane as well, and the big question is, when will that happen?” Interim advice from the Joint Committee on Vaccination and Immunization (JCVI) this month advised the NHS to prepare for an autumn booster program, but no final decision has been made.
It’s uncertain if vaccination protection has decreased enough to merit boosters, and many specialists feel that other countries want the doses more urgently.
The UCL researchers looked at the blood of 605 persons who had been vaccinated, most of whom were in their 50s and 60s.
The researchers discovered that antibody levels varied greatly amongst individuals, but that a double dosage of Pfizer/BioNTech vaccine produced considerably more antibodies against the coronavirus than two doses of the Oxford/AstraZeneca vaccine.
Antibody levels were typically around 7,500 units per ml three to six weeks following full vaccination with Pfizer, but had more than halved to 3,320 units per ml after ten weeks.
Antibody levels peaked at around 1,200 units per ml for AstraZeneca and normally dropped to 190 units per ml after 10 weeks.
The researchers have noticed the same pattern in another 4,500 study participants since reporting their findings in a letter to the Lancet.
While antibody levels are vital for protection, the immune system also has additional defenses that develop as a result of infection or vaccination.
Antibody levels will diminish over time, and the immune system will “remember” the infection through memory B cells.
If the infection infects these cells, they quickly produce antibodies that are specific to the virus.
T cells provide further protection by destroying contaminated cells and limiting the degree of illness.
“Antibodies aren’t a perfect indicator of risk; we don’t know if there’s a magic number where the risk of infection or hospitalization becomes significant,” Aldridge explained.
“Therefore, we believe these results support the JCVI rationale for boosters, with priority for the clinically vulnerable, the over-70s, and all those residing in residential care homes for older adults.”
Antibodies loss is a clue it immunizations may wear off over time, but it doesn’t say when that happens.
Until those who had their second doses early in the rollout start showing up in hospitals, public health officials won’t know for sure.
Before then, a decision on the booster program is expected.
“The weakening of antibody responses over time may encourage booster techniques,” said Prof Eleanor Barnes, a hepatologist at the University of Oxford, “particularly in the setting of a third wave in the UK with Delta variant, where infection episodes are now common after two vaccination doses.”
“But, memory B cells and T cells may potentially protect from severe disease, even with diminishing antibody levels,” she added, adding that the necessity for boosters in the UK “has to be balanced with the equitable administration of first and second vaccine doses globally.”
“Studies like this do not in themselves give evidence of fading vaccination protection, but they are incredibly important to help us understand what’s going on if population-based studies demonstrated any drop-off in protection with increasing time since inoculation,” said Prof Matthew Snape, an Oxford vaccinologist.
“A decrease in antibodies in the blood after vaccination is to be expected, although it does not always imply an increased risk of disease.”
Protection against infection may be determined by the presence of antibodies in the respiratory lining, and T cells may give protection against the progression of infection to severe disease.
“Yet, it is obvious that vaccine protection for months to years after vaccination cannot be assumed, highlighting the significance of continued surveillance for any increase in outbreak illnesses.”

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