Uhhh... you do know that steroid injections can impair your immune system, right? It's not known that it makes you more vulnerable to COVID-19, but it very well might.
Fact: There is low-quality evidence that a single intra-articular corticosteroid injection may increase the risk of contracting the influenza virus. No study has yet been published that examines whether a corticosteroid injection increases the risk of contracting COVID-19 or alters the clinical course of a subsequent infection. While caution is advised based on this indirect evidence, more studies are needed to determine full correlation of corticosteroid administration and risks of contracting COVID-19.
Systemic Corticosteroid Effects on Immune Cell Function
Therapeutic corticosteroids have wide-ranging physiologic effects [2]. The effect of systemic corticosteroids on immune system “compromise” is known. Dr. Anthony Fauci, Director of the US National Institute of Allergy and Infectious Diseases since 1984 and one of the leaders of the US Coronavirus Task Force, published a seminal article on the subject in 1976 [3]. The human immune system can be simplified into two arms: 1) the innate immune system and 2) the adaptative immune system. The innate immune system is composed of neutrophils, macrophages, monocytes (collectively referred to as phagocytes), and mast cells, which react to foreign pathogens within minutes to hours. Mobilization of these cells is aided by complement activation and cytokines but does not require the presentation of an antigen and does not lead to immunological memory. The adaptive immune system, composed of lymphocytes, precisely recognizes unique antigens through cell surface receptors. The adaptive immune system is activated when the innate immune response is insufficient to control an infection. Systemic corticosteroid therapy may adversely affect both the innate and adaptive immune response. The ability of neutrophils to migrate to sites of infection is impaired by corticosteroids [4]. Macrophage and monocyte function may also be inhibited by corticosteroids [5]. The capability of plasma cells (terminally differentiated B-lymphocytes) to produce immunoglobulins IgG and IgA is reduced 10–20% by corticosteroids [6]. Alternatively, a small body of literature indicates that corticosteroids may enhance the innate immune response in the epithelium in certain regions [7]. However, the balance of corticosteroid effects is generally considered to impair the immune response. This literature describes the effects of oral and other forms of systemic corticosteroid administration; the exact correlation to injection therapy is unknown, yet plausibly has similar effects.
Corticosteroid Injections and COVID-19 Infection Risk
You doctor would have to assess the relative benefits and hazards of using steroids to treat you. And each of us is different, so in your case, it might be advisable, even if it's not advisable for most people. I managed an allergy-immunology clinic in the AF, and my policy was that the techs would never give a live-virus vaccine to anyone who was immune-compromised or on any immune-suppressive medication without a consult by the clinic physician. Every doctor who rotated through the clinic supported the policy.