COVID-19 is caused by a virus known as SARS-CoV-2, which is similar in structure to two other viruses that have caused recent outbreaks: SARS-CoV, which caused an outbreak of SARS in 2003, and MERS-CoV, the cause of a 2012 outbreak of Middle East Respiratory Syndrome.

University of Pittsburgh School of Medicine scientists have isolated the smallest biological molecule to date that completely and specifically neutralizes the SARS-CoV-2 virus, which is the cause of COVID-19. This antibody component, which is 10 times smaller than a full-sized antibody, has been used to construct a drug - known as Ab8 - for potential use as a therapeutic and prophylactic against SARS-CoV-2.

Immune reactions caused by vaccination can help protect the organism, or sometimes may aggravate the condition. It is especially important now when multiple vaccines against COVID-19 are being developed. The top immunologists analyse types of immune response to predict what kind of vaccine would be the best.

SARS-CoV-2 arrived in Washington State somewhere between late January and early February 2020, sparking rapid community transmission of the virus that went undetected for several weeks before this community spread became evident, prompting a change in testing criteria to emphasize individuals with no travel history. That's the scenario proposed by Trevor Bedford and colleagues after their analysis of the genetic sequences of 455 SARS-CoV-2 viruses from the Washington State outbreak collected between January 19 and March 15, 2020.

Using public transportation, visiting a place of worship, or otherwise traveling from the home is associated with a significantly higher likelihood of testing positive with the coronavirus SARS-CoV-2, while practicing strict social distancing is associated with a markedly lower likelihood, suggests a study from researchers at the Johns Hopkins Bloomberg School of Public Health.

Early findings from researchers at Children's Hospital of Philadelphia (CHOP) show that convalescent plasma appears to be a safe and possibly effective treatment for children with life-threatening cases of COVID-19. The results were published online Friday by the journal Pediatric Blood and Cancer.

Results from two early-phase Russian non-randomised vaccine trials (Sputnik V) in a total of 76 people are published today in The Lancet, finding that two formulations of a two-part vaccine have a good safety profile with no serious adverse events detected over 42 days, and induce antibody responses in all participants within 21 days.