Science & Technology

COVID-19 antibody lasts at least 9 months after infection

According to a new study, COVID-19 antibody lasts for at least 9 months after infection.

Testing of the entire Italian town has shown that antibody levels remain high for 9 months after SARS-CoV-2 infection, whether symptomatic or asymptomatic.

Researchers at the University of Padua and Imperial College London said that in February / March 2020, more than 85% of the 3,000 inhabitants of Vo’in Italy were affected by SARS-CoV-2, the virus that causes COVID-19. Tested and tested for infections. Again for antibodies to the virus in May and November 2020.

The team found that 98.8% of people infected in February / March showed detectable levels of antibodies in November, making no difference between those suffering from COVID-19 symptoms and those asymptomatic. I found. The results will be published today (July 19, 2021). Nature Communications..

COVID Researcher Test Kids

A researcher who tests a child as part of a study. Credit: Andrea Crisanti

Antibody levels were tracked using three “assays” that detect different types of antibodies that react with different parts of the virus. The results showed that all antibody types showed some reduction between May and November, but the rate of decay was assay-dependent.

The team also found cases of elevated antibody levels in some people. This suggests the possibility of viral reinfection and strengthens the immune system.

Dr Ilaria Dorigatti, lead author of the Imperial MRC Global Infectious Diseases Analysis Center and the Abdul Latif Jameel Emergency Analysis Institute for Diseases (J-IDEA), said: Significantly, it suggests that the strength of the immune response does not depend on symptoms or severity of infection.

“But our research shows that antibody levels sometimes change significantly depending on the tests used. This is obtained at different tests and at different times in different parts of the world. This means that care must be taken when comparing estimated levels of infection in different populations. “

Professor Enrico Lavezzo of the University of Padua said: Infection.

“However, a follow-up performed about 9 months after the outbreak found that the amount of antibody was low, so long-term monitoring of antibody persistence is required.”

The team also investigated the infection status of household members to estimate the likelihood that infected members would inherit the infection within the household. Their modeling suggests that people infected with SARS-CoV-2 have about a quarter chance of passing the infection to their families, and most infections (79%) are caused by 20% of infections. I will.

This finding confirms that there is a large difference in the number of secondary cases produced by infected individuals, the majority of infections do not produce any more infections, and the minority of infections produce a large number of infections. ..

The major difference in how one infected person infects others in the population is that behavioral factors are key to epidemic control, limiting not only physical distance, but also the number of contacts and wearing a mask. Even the highly vaccinated population is ill, suggesting that it remains important to reduce the risk of infection.

The team’s dataset includes the results of two mass PCR test campaigns conducted in February and March and antibody surveys conducted in May and November, with the impact of various control measures. I was able to separate it.

They showed that without case isolation and short blockade, manual contact tracing alone would not have been sufficient to curb the epidemic.

Professor Andrea Crisanti, Project Leader of the Imperial School of Life Sciences and the University of Padua’s School of Molecular Medicine, said: Contact-Without mass screening, it would have had a limited impact on the containment of the epidemic. “

Dr. Drigatti added: “It’s clear that the epidemic hasn’t ended, both in Italy and abroad. I think it’s fundamentally important to continue the first and second vaccinations and strengthen surveillance, including contact tracing. It remains essential to call attention and limit the risk of obtaining SARS-CoV-2. “

Reference: July 19, 2021 Nature Communications..
DOI: 10.1038 / s41467-021-24622-7

COVID-19 antibody lasts at least 9 months after infection COVID-19 antibody lasts at least 9 months after infection

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