This study aims to employ a simple finger-prick home test to detect post vaccination antibody levels. The investigators will compare antibody responses in patients with severe asthma on varying treatment regimes (biologics, daily steroids, inhalers-only) with healthy, age-matched controls to study if the magnitude and range of responses vary between severe asthmatics and healthy individuals.

SARS-CoV-2 and the resulting COVID-19 pandemic has had a major impact on quality of life in people with severe asthma. Careful isolation and lockdown measures have protected many patients, but with major impacts on wellbeing and mental health. Vaccination opens a "light at the end of the tunnel" by protecting against COVID-19. However, the following questions remain unanswered for Covid vaccination in severe asthma: 1) What are patients' expectations/attitudes towards vaccination? 2) Will vaccines induce good immune responses which protect from Covid-19 infections? The first question is being addressed by a survey created SHARP, a European Clinical Research Collaboration on severe asthma- people with asthma from the UK and Europe will be invited to complete the survey. To complement this, the investigators propose a UK pilot study (carried out in up to four severe asthma centres) to measure immune responses following vaccination in 200 people with severe asthma. The investigators will invite 120 people receiving asthma biologics (monoclonal antibodies), 40 people receiving asthma inhalers, 40 people needing daily steroid tablets to control their asthma, and 50 age-matched healthy people. Immune responses will be studied using a simple home blood antibody test posted to participants. By pricking their finger, patients will collect 5-6 drops of blood in a small test tube and will post back on the same day to a laboratory in London. Tests will be done twice: after the first and second vaccine doses.

The study will help us understand if the body's immune response to the COVID-19 vaccine is different in people with severe asthma who are on different treatments to manage their symptoms.

Inclusion criteria:

1. Age ≥ 16 years

2. For asthma patients:

   1. Diagnosis of severe asthma (based on ATS/ERS consensus criteria)
   2. Group A: Currently receiving an asthma biologic with treatment having started at least 3 months before first COVID-19 vaccine
   3. Group B: on maintenance oral steroids at a dose of ≥5mg prednisolone (or equivalent) per day (at the time of first COVID-19 vaccine)
   4. Group C: not on asthma biologic or maintenance oral steroids (at the time of vaccination) or stopped ≥3 months prior to first COVID-19 vaccine

Exclusion criteria:

1. Current pregnancy or planning a pregnancy within the next 6 months

2. Current malignancy

3. Diagnosis of immunodeficiency requiring treatment

4. Additional exclusion criteria for asthma patients:

   1. Group A: maintenance oral steroids at the time of first COVID-19 vaccine
   2. Group B: on an asthma biologic at the time of first COVID-19 vaccine

5. Additional exclusion criteria for healthy controls cohort (as assessed by research team):

   1. No history of asthma or significant other lung disease
   2. Severe chronic inflammatory disease
   3. Severe cardiac disease
   4. Diabetes

6. Previous proven COVID-19 infection

7. Inability to provide informed consent

8. Unwilling to have vaccination

9. Participation in another clinical trial involving an investigational medicinal product (IMP).

The study will recruit patients that attended the severe asthma clinic. To recruit age-matched controls we will randomly approach the patients and ask if their partners (or age-matched family members or friends) would like to participate in the study.