SARS-CoV-2 Antibodies Stay Stable or Rise Seven Months After Infection: Study

Researchers at the Barcelona Institute for Global Health (ISGlobal) in Spain also suggest that pre-existing antibodies to cold coronaviruses could protect against COVID-19.

They noted that in order to predict the course of the pandemic and develop effective strategies, it is essential to better understand the dynamics and duration of immunity against SARS-CoV-2.

Researchers have followed a group of healthcare workers since the start of the pandemic to assess antibody levels against different SARS-CoV-2 antigens over time.

“This is the first study to assess antibodies against such a large panel of SARS-CoV-2 antibodies over 7 months,” said Carlota Dobano, ISGlobal researcher, who led the study.

The team analyzed blood samples from 578 participants, taken at four different times between March and October 2020.

They measured the level and type of IgA, IgM or IgG antibodies to six different SARS-CoV-2 antigens as well as the presence of antibodies against the four coronaviruses that cause colds in humans.

The researchers also analyzed the neutralizing activity of the antibodies in collaboration with researchers from the University of Barcelona.

The results show that the majority of infections among healthcare workers occurred during the first wave of the pandemic.

With the exception of the IgM and IgG antibodies against the nucleocapsid (N), the rest of the IgG antibodies remained stable over time, confirming the results of other recent studies.

Immunoglobulin G (IgG), the most abundant type of antibody, is found in all body fluids. These antibodies are produced in the later stages of an infection and help the body recover.

“Surprisingly enough, we even saw an increase in anti-IgG peak antibodies in 75% of the participants from the fifth month onwards, without any evidence of re-exposure to the virus,” said Gemma Moncunill, co-lead author of the study. .

No reinfection was seen in the cohort, the researchers said.

The study also suggests that antibodies to cold human coronaviruses (HCoV) may confer cross-protection against COVID-19 infection.

People infected with SARS-CoV-2 had lower levels of anti-HCoV antibodies, the researchers said. In addition, asymptomatic individuals had higher levels of IgG and anti-HCoV IgA than those with symptomatic infections, they said.

“Although cross-protection with pre-existing cold coronavirus immunity remains to be confirmed, this could help explain the large differences in susceptibility to the disease among the population,” Dobano added.

This story was posted from an agency feed with no text editing.