Antibody protection after light COVID-19 may not last; Reuters estimates that 100 million people have had long COVID

By Nancy Lapid

(Reuters) – The following is a summary of recent research on COVID-19. They include research that requires further research to verify the findings and is yet to be verified through peer review.

Perhaps the protection of antibodies against light COVID-19 will not last

Almost all who had a mild case of COVID-19 still have antibodies to coronavirus a year later, but this may not protect them from new variants, a small study suggests. Of the 43 Australians who contracted mild COVID-19 at the start of the pandemic, 90% still had antibodies 12 months later. But only 51.2% had antibodies that showed “neutralizing activity” against the original version of the virus and only 44.2% had antibodies that could neutralize the early Alpha variant, the University of Adelaide research team reported on Thursday before the peer review of medRxiv https: //. Neutralizing antibodies against the currently dominant and highly transmissible Delta variant were found in only 16.2%, 11.6% against Gamma, and only 4.6% against Beta. Those with mild COVID-19 are “vulnerable to the circulating SARS-CoV-2 variant and newly created 12 months after healing,” the researchers said. The findings “reinforce the potential benefit” of adapting vaccine promoters to the variants currently in circulation, similar to how annual flu vaccines adapt to current flu strains, they said.

100 million have or have had long-term COVID, according to research estimates

More than 40% of COVID-19 survivors worldwide have had lasting effects of the disease, according to researchers at the University of Michigan, based on a review of 40 previous studies from 17 countries that have studied what is known as a long patient experience. COVID, defined as a new or persistent symptom for four weeks or more after infection. The prevalence rises to 57% among survivors who had to be hospitalized, the researchers reported on Tuesday at medRxiv https: //, before peer review. The rate was 49% among surviving women and 37% among men, they said. The approximate COVID rate was 49% in Asia, 44% in Europe and 30% in North America. Among the most common problems, fatigue is estimated to affect 23%, and shortness of breath, joint pain and memory problems affect 13%. The study probably did not cover all cases of long-term COVID, the researchers say. “The WHO (World Health Organization) is based on an estimated 237 million COVID-19 infections worldwide. These health consequences, they warn, can “cause significant stress in the health care system.”

The effect of the virus on blood thinning molecules is to cause clots to form

Dangerous blood clots are often seen in patients with COVID-19, in part because the vertices of the virus bind to blood molecules that play a key role in preventing coagulation, and are thus deactivated as new research shows. Because the virus is associated with them, “these molecules (heparan sulfate / heparin) cannot perform their normal anticoagulant activity,” explains Jingyu Yan of the Dalian Institute of Chemical Physics in China. Blood clots associated with COVID-19 often damage the lungs and other organs and can cause heart attacks and strokes. Excessive coagulation has been attributed to high levels of inflammation caused by SARS-CoV-2 infection. It is not yet clear whether the virus itself has a direct effect, Yan’s team reported in the International Journal of Biological Macromolecules https://www.sciencedirect.com/science/article/pii/S0141813021022704. Fortunately, they noted that the usual practice of giving blood-relieving drugs to COVID-19 patients can “significantly reduce” the coagulation caused by the virus.

Click on a Reuters chart https://tmsnrt.rs/3c7R3Bl about developing vaccines.