Convalescent serology for RCGP RSC Practices

If you have been contacted by RCGP RSC to organise convalescent samples, please carefully read the information below. Please pay particular attention to ‘Inclusion and Exclusion criteria’ and ‘Informed consent’.Thank you for your support in organising Week 3-6, Week 12 and Week 20 convalescent serology sample collection.
  1. Contact the patient, explain the surveillance, provide all pertinent information (Protocol detailed below) and discuss any questions the patient may have. Please also provide the patient information leaflet for the patient to read and allow enough time for him/her to ask follow up questions.Note:
    – there will be no results provided to the patient or practice
    – this is purely voluntary
    – ensure informed verbal consent is obtained
  2. If the patient provides informed verbal consent, please arrange for a blood sample at week 3-6, week 12 and week 20. In order to be included in this surveillance a minimum of two time-points is required. (Further details provided in protocol below.)
  3. When the patient attends your practice, please provide the patient information leaflet (download here) and provide an opportunity to discuss any questions the patient may have. Following informed verbal consent, please take the blood sample and complete the lab request form (download here). You will then need to package appropriately, include the lab request form inside the cardboard box, and post to VEU Manchester.

Your practice should already be equipped with serology kits from the RCGP RSC. If you have run out of kits, please advise the RCGP RSC contact when you speak to them.

  1. Please code as indicated on the lab request form, and keep a list of these patients as we will contact you regarding these for payments.

Severity assessment of COVID-19 requires the detection of asymptomatic and mild infections and the determination of the true number of infections within the general population. The number of true infections can be determined if the prevalence of immunity of the population prior to, during and after the epidemic are known. Public Health England (PHE) are conducting a number population-based surveys in England to inform our understanding of the extent of transmission of SARS-CoV-2. This requires the collection of representative serum samples across England. As part of this, convalescent sera – serum from patients who have had and are recovering from a confirmed COVID-19 infection are required to understand the antibody response following infection and to validate the assays used to detect antibodies.

– To obtain serial convalescent samples from 4 weeks to 20 weeks after symptom onset, from PCR confirmed individuals across all age groups, to determine the duration of the COVID-19 antibody response.

– To obtain convalescent samples from patients with a) mild disease and b) moderate or severe disease (as defined by requiring hospital admission) to understand the antibody response relative to disease severity.

– To use convalescent samples to evaluate the sensitivity of assays used to detect antibodies to SARS CoV-2.

The seroprevalence study will use serial convalescent samples from patients who have recently been diagnosed with COVID-19 by PCR testing to understand the antibody response following infection and to assist with assay validation. Convalescent serum will be obtained from two main sources:

  1. A study conducted by Mary Ramsay et al. which obtained convalescent samples from “FF100” patients (i.e. the first 100 patients to be diagnosed in England)
  2. The RCGP RSC network.

Adult patients (≥ 16 years old) or the parent / legal guardian of children (< 16 years old) will be asked to consent to:

  1. Answer a short questionnaire regarding their symptom onset and disease severity;
  2. Submit sequential blood samples for antibody testing.

Potential participants will be categorised according to age and disease severity.

Patients will be categorised according to one of 3 age groups:

– Children aged < 16

– Adults aged 16 – 64

– Adults aged ≥ 65 years.

Patients will be categorised as having either “mild” disease or “moderate / severe” disease using the following classification:

– Mild: COVID-19 symptoms were managed in the community and did not require an overnight hospital stay.

– Moderate or severe: COVID-19 symptoms required a hospital stay of at least one night.

Note: RCGP RSC contact will inform the practice of which age group and disease severity to sample from

Patients will be asked to provide serum samples at the following 3 time points after symptom onset +/- 3 days:

– 3 – 6 weeks (i.e. day 21 to day 42) after symptom onset

– 12 weeks (i.e. day 84 +/- 3 days)

– 20 weeks (i.e. day 140 +/- 3 days)

It is anticipated that not all patients will be able to submit all 3 samples, however, a minimum of 2 samples per patient will be required.

Sample numbers are capped for each age group and disease severity.

Required hospitalisation for treatment of COVID-19
Age No Yes
Children aged <16 50 0
Adults aged 16-64 0 25
Adults aged ≥ 65 years 50 25

No: COVID-19 symptoms were managed in the community and did not require an overnight hospital stay.
Yes: COVID-19 symptoms required a hospital stay of at least one night for treatment of COVID-19.

Adults (≥16 years old) or children (< 16 years old), who:

  • Have been diagnosed with COVID-19 by PCR.
  • Can give informed verbal consent for participation in the study (adults), or in the case of children aged < 16, whose parent or legal guardian can give informed verbal consent for participation in the study.
  • Are able to submit a minimum of 2 convalescent samples at the appropriate time points after symptom onset.

The participant may not enter the study if ANY of the following apply:

  • Adults unable to understand the study information and give consent to take part in the study.
  • Eligible children with parents or legal guardians who are unable to understand the study information and give consent.
  • Patients who have not previously received a diagnosis of COVID-19 by PCR testing.
  • Patients for whom information on date of symptom onset, date of PCR swab, or whether they were admitted to hospital is not available.

The patient information leaflet should be provided to the patient by the GP in either a physical or in electronic format. Only verbal consent is required from the patient, parent or guardian including adults for any minors for whom they are parents/guardians. This is in line with NHS Health Research Authority guidelines.1

Consent is obtained verbally and can be withdrawn subsequently if the patient does not wish the blood sample to be taken. Participants are not required to give a reason for withdrawal. Withdrawn participants should be sought to be replaced with a patient from the same age and disease severity category.

1NHS Health Research Authority. Consent and Participant Information Guidance. Principles of Consent: General principles and role of Participant Information Sheets. Accessed from on 17 June 2020.

The following data should be collected at the time of each sample and should be entered on the sample request form (which will be prepared by PHE):

– Patient name


– NHS No.

– GP Details

– Date sample collected

– Date of symptom onset

– Date PCR test conducted

– Whether the patient has been admitted to hospital overnight for treatment of COVID-19 and the date that they were admitted

– Ethnicity

Samples will be collected at the GP practice following standard infection control / PPE procedures that are in place at that practice. No further precautions are required.



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