COVID-19 reinfection unlikely for at least 6 months, study finds

Prior COVID-19 infection may offer at least six months of immunity against the virus a new study suggests. File

"Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months of diagnosis", wrote the authors.

"These so-called memory T-cells after SARS-CoV-2 infection look similar to those after a real flu", said study co-author Dr Maike Hofmann, a scientist at the Department of Medicine II at the Medical Center - University of Freiburg.

Previously it was feared antibodies wane after just a couple of months but a number of recent studies have shown both T-cells and antibodies last for at least six months, meaning those who have recovered from an infection are protected for at least that amount of time. The researchers said that there was about a 200-fold range in the level of antibody responses among the adults.

"The findings link inflammatory cell death induced by TNF-alpha and IFN-gamma to COVID-19", Kanneganti said in the release. The researchers said there appeared to be an increase in memory B cells over time.

The researchers also simulated three types of saliva - thin, medium, and thick.

For the past nine months, COVID-19 has been spreading from person to person in the US while scientists and medical professionals scramble to figure out the novel virus' patterns.

A study published Friday by Oxford University ensures that people infected with coronavirus have little chance of returning to the disease in at least six months.

The study, which has not yet been peer-reviewed, took into consideration various immune facets, including B cells, antibodies and T cells.

London- In a major study, researchers have claimed that infectiousness peaks early in Covid-19 patients, highlighting the need to quickly identify and isolate cases before the virus spreads.

The more antibodies people had, the lower their chances of re-infection. "This means that the population level of immunity may be rising which will eventually lead to reduced transmission", Evan said adding that this, coupled with immunity being conferred by vaccination, offers prospects of transmission of the virus being markedly reduced over the next year or so.

"Secondly, it is probably very good news for vaccines also being able to provide immunity that is more than very short-term. We do not know that for certain yet, but it is encouraging", said Evans.

The report used meta-analysis to assess 98 studies on Covid-19, SARS and MERS. Various previous studies have shown that immunity against covid-19 can last for around six months.

In this study, the team of researchers at the La Jolla Institute of Immunology in California, and the Icahn School of Medicine at Mount Sinai in NY, investigated multiple compartments of circulating immune memory to SARS-CoV-2 in 185 Covid-19 cases, including 41 cases more than six months post-infection.



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