Tag Archive for: COVID-19 antibodies

Antibodies improve in quality for months after COVID-19 vaccination

Antibodies improve in quality for months after COVID19 vaccination - بهبود تدریجی کیفیت آنتی بادی های کرونایی

For at least six months after COVID-19 vaccination, antibodies produced by immune cells become steadily more formidable and more precisely targeted against the virus that causes COVID-19, according to a study of the antibody response to the Pfizer-BioNTech vaccine by researchers at Washington University School of Medicine in St. Louis.

The idea that antibodies increase in quality as they decrease in quantity will come as no surprise to immunologists. The process was described in animals by Washington University immunologists Herman Eisen, MD, and Gregory Siskind, MD, in 1964. But this study, published in Nature, is the first to track the maturation of the antibody response in detail in people.

The findings suggest that declining antibody levels in the months after vaccination primarily represent a shift to a sustainable immune response. Producing vast quantities of antibodies burns a lot of energy. The immune system cannot sustain such a high level of activity indefinitely, so it gradually switches to producing smaller amounts of more powerful antibodies.

Even quite low levels of antibodies would continue to provide some protection against disease, the researchers said — as long as the virus doesn’t change.

Immune cells that produce antibodies are from the B cell family. Following the B cell response through all of its stages — from initiation through peak antibody production to the emergence of memory cells that can quickly churn out new antibodies the next time the body encounters the same virus — requires repeatedly taking samples from parts of the body that can be hard to access. At different stages in the process, key members of the B cell family are located in the blood, the lymph nodes and the bone marrow. Getting B cells from the lymph nodes is technically challenging and involves using ultrasound to locate minuscule immune structures called germinal centers within the lymph nodes. Obtaining a sample of bone marrow involves inserting a needle into the pelvic bone.

Release date: 15 February 2022
Source: Washington University School of Medicine

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COVID-19 antibodies persist at least nine months after infection

COVID19 antibodies persist at least nine months after infection - میزان ماندگاری آنتی بادی کرونایی

Testing of an entire Italian town shows antibody levels remain high nine months after SARS-CoV-2 infection, whether symptomatic or asymptomatic.

Researchers from the University of Padua and Imperial College London tested more than 85 percent of the 3,000 residents of Vo’, Italy, in February/March 2020 for infection with SARS-CoV-2, the virus that causes COVID-19, and tested them again in May and November 2020 for antibodies against the virus.

The team found that 98.8 percent of people infected in February/March showed detectable levels of antibodies in November, and there was no difference between people who had suffered symptoms of COVID-19 and those that had been symptom-free. The results are published in Nature Communications.

Release date: 19 July 2021
Source: Imperial College London

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New evidence COVID-19 antibodies, vaccines less effective against variants

New evidence COVID-19 antibodies, vaccines less effective against variants - تاثیر کمتر واکسیناسیون علیه کروناویروس جدید

New research at Washington University School of Medicine in St. Louis indicates that three new, fast-spreading variants of the virus that cause COVID-19 can evade antibodies that work against the original form of the virus that sparked the pandemic. With few exceptions, whether such antibodies were produced in response to vaccination or natural infection, or were purified antibodies intended for use as drugs, the researchers found more antibody is needed to neutralize the new variants.

The findings, from laboratory-based experiments and published March 4 in Nature Medicine, suggest that COVID-19 drugs and vaccines developed thus far may become less effective as the new variants become dominant, as experts say they inevitably will. The researchers looked at variants from South Africa, the United Kingdom and Brazil. Nature Medicine

Release date: 04 March 2021
Source: Washington University School of Medicine