Combining studies of eight cohorts across the United States, a team of researchers accelerated the collection of relevant data to answer questions about the immune response required for long-term protection against SARSCoV2. A description of the cohort, assays used, and event definitions was recently published in the open publication mSphere of the American Society for Microbiology.

Long-term observational studies (studies using continuous or repeated measures to monitor specific individuals over time) are necessary to address important questions about the persistence and efficacy of anti-SARS-CoV-2 immune responses. Often, individual cohorts have limited longitudinal data or number of participants to draw robust conclusions. To overcome these limitations, harmonized but independent cohorts – PARIS (protection for rapid immunity to SARS-CoV-2) – and SPARTA (SARS seroprevalence and respiratory assessment) were established in different geographical areas of the United States. These cohorts provide an agile and fast way to form a network suitable for collecting biosamples and other data.

“We started the PARIS cohort at Icahn School of Medicine in Mount Sinai because we wanted to know three things: how long SARS-CoV-2 antibody responses last during infection, whether antibody responses protect against re-infection, and how much antibody an individual needs. to protect, “said the senior researcher Florian Krammer, Ph.D., Professor of Microbiology and Pathology at Icahn School of Medicine in Mount Sinai.

“It is very important to study the immune responses to the infection itself over time when you have a new virus, to look at the protective effects of the immune responses caused by the infection, and also to look at what happens when people get vaccinated,” the lead study added. author Viviana SimonMD, Ph.D., Professor of Microbiology, Infectious Diseases and Pathology at Icahn School of Medicine in Mount Sinai.

In a new study, to find out the rate of recurrence of SARS-CoV-2 infection and the correlations of protection, the researchers established 8 different longitudinal cohorts in the umbrella of the PARIS / SPARTA studies in 2020. The cohorts included seropositive and seronegative participants at high risk for infection. The original PARIS study focused on health workers in New York City, one of the first centers of the pandemic in the United States, but other cohorts targeted other populations in addition to health workers, including color communities, first aid workers, and students.

When SARS-CoV-2 vaccines were rapidly introduced in the United States in mid-December 2020, many of the cohorts are now also monitoring vaccine immune responses in individuals who are both seronegative and seropositive at the time of immunization. There were 8,741 participants in the eight cohorts. In all eight cohorts, the researchers monitored COVID-19 and non-COVID-19 patients by collecting data and bioassays to measure immune responses (e.g., antibody responses to the SARS-CoV-2 peak protein) at least every two months.

“We saw that previously infected individuals had a relatively stable antibody response and were protected from re-infection unless the new infection was a variant of Omicron,” Dr. Krammer said. The group looked at how the immune responses behaved in previously infected people compared with those who had not yet been infected. The researchers showed that previously infected individuals had a very rapid immune response even after a single dose of the vaccine. “Vaccination enhances protection and provides better immunity,” said Dr. Krammer.

Source: ANI