CDC is conducting a nationwide COVID-19 seroprevalence survey of blood donors to:
- Perceive the share of individuals in the USA who’ve antibodies towards SARS-CoV-2, the virus that causes COVID-19.
- Observe how this share adjustments over time.
This research is the biggest nationwide COVID-19 seroprevalence survey up to now. CDC is collaborating on this challenge with the Nationwide Institutes of Well being (NIH), the Meals and Drug Administration (FDA), Vitalant Analysis Institute (VRI), Westat Inc., and quite a few blood assortment organizations throughout the USA. CDC is offering technical help and monetary help to VRI and collaborating establishments.
Performed underneath REDS-IV-P (Recipient Epidemiology and Donor Analysis Examine IV Pediatric) programexterior icon, this seroprevalence survey expands an ongoing challenge referred to as the RESPONSE researchexterior icon (REDS-IV-P Epidemiology, Surveillance and Preparedness of the Novel SARS-CoV-2 Epidemic) funded by the NIH. From March to August 2020, the RESPONSE research collected present blood donation samples from six U.S. areas (about 1000 samples per thirty days) for testing for SARS-CoV-2 antibodies.
The expanded seroprevalence survey contains greater than 60 areas, representing all 50 states and Puerto Rico. Since July 2020, nameless blood donation samples (about 2,000 per thirty days) from every area are being collected and examined. The survey will proceed till January 2022. A bigger variety of samples are being collected from blood facilities in areas that embody a number of states or are racially and ethnically numerous. Total, about 1.5 million samples will likely be examined. For every area, the seroprevalence will likely be estimated for the area total and by age group, intercourse, and race/ethnicity.
Info on blood donation samples examined
When blood is donated in the USA, small samples are taken from every blood donation to seek out out the donor’s blood kind. The blood can be screened for sure infectious illnesses to ensure it’s protected for transfusion to sufferers. VRI and collaborating organizations will gather these reserved donation samples and take a look at for antibodies to SARS-CoV-2. The serology take a look at is totally different than the nasal swab take a look at and can’t decide if an individual had SARS-CoV-2 an infection when the blood was drawn. As an alternative, it offers info on if an individual was contaminated previously. It sometimes takes 1 to three weeks after an infection for an individual with SARS-CoV-2 to supply detectable antibodies.
Deciphering Antibody Outcomes from This Survey
This survey has limitations that must be thought of when decoding the outcomes:
- Individuals who donate blood could differ from the final inhabitants. Individuals who donate blood are typically wholesome, non-pregnant adults. Youthful folks and other people from sure racial and ethnic teams could also be underrepresented amongst those that donate blood. Moreover, individuals who don’t donate blood (e.g., reside in institutionalized settings) aren’t included on this survey. Though CDC will use statistical strategies to account for variations in age, intercourse, ethnicity, race, and placement of residence, the seroprevalence estimates is probably not the identical because the true seroprevalence among the many whole inhabitants.
- The outcomes of an antibody take a look at can generally be constructive for individuals who weren’t beforehand contaminated with SARS-CoV-2. That is extra widespread in communities with low an infection charges. This is called a false-positive end result and may make it seem like extra folks have been contaminated locally than actually have been.
- The outcomes of an antibody take a look at can generally be destructive for individuals who have been beforehand contaminated with SARS-CoV-2. This is called a false-negative end result. It’s attainable that some folks could be contaminated with SARS-CoV-2 however don’t make detectable antibodies. It is usually attainable that antibody ranges could lower over time. When this occurs, it could actually make it seem like fewer folks have been contaminated locally than actually have been.
- We have no idea if having SARS-CoV-2 antibodies protects somebody from getting contaminated with SARS-CoV-2 once more. Different research are deliberate to study extra about SARS-CoV-2 antibodies, together with how lengthy the antibodies final, if they supply safety towards getting contaminated once more.
- This seroprevalence survey was not designed to take a look at threat components for an infection, resembling an individual’s occupation or underlying well being circumstances.
Security of US blood provide
There have been no reported instances of individuals getting SARS-CoV-2, the virus that causes COVID-19, from a blood transfusion. Usually, respiratory viruses resembling SARS-CoV-2 aren’t unfold by blood transfusion.
Even so, individuals who need to donate blood are evaluated for any present or previous sickness. If they’re in poor health on the time of donation, they can’t donate blood. For instance, they should have regular physique temperature on the day of donation. See FDA suggestions for blood donation amongst individuals identified with or suspected to have COVID-19exterior icon for extra info.