Heart Transplant And COVID-19 Vaccine necessity and effectiveness

The unprecedented challenges of the COVID-19 pandemic have led to rapid transmission and high infectivity rates across the globe. Till now, more than 3.6 million deaths have been reported worldwide due to SARS-CoV-2 infections. In this pandemic, healthcare professionals have also been confronting extreme challenges of managing patients with heart transplants and those on transplant waiting lists. 

Heart transplant patients are more vulnerable to COVID-19 infections. There has been a lot of information published regarding the heart transplant and COVID-19 vaccine. Let’s look at the vulnerability of heart transplant patients to COVID-19 and what the research says about a heart transplant and COVID-19 vaccine. 

Why Heart Transplant Patients Are at Increased Risk of Contracting COVID-19?

Research has shown that the mortality rate of COVID-19 is high in patients undergoing heart transplantation. Heart transplant patients have therapeutically or clinically suppressed immunity because of the donor heart transplanted in them. Therefore, they are more likely to contract severe COVID-19 infection. Such immunosuppressant patients not only acquire prolonged COVID-19 infection but also are at increased risk of infection with COVID-19 variants [1].

Why COVID-19 Vaccines Are Less Effective In Heart Transplant Patients?

The American Society for Transplantation (AST) and the International Society for Heart and Lung Transplantation (ISHLT) have shed some light on the heart transplant and COVID-19 vaccine. Patients who have undergone heart transplantation exhibit a weakened immune system in response to COVID-19 vaccination. Also, the COVID-19 vaccines show less efficacy in immunosuppressed patients. 

The COVID-19 vaccine works by exposing your immune system to the virus and tells your body’s immunity to activate the defense mechanisms before exposure to the actual infection. If you are a heart transplant patient, your immunosuppressed body will not have a strong immunity in response to the COVID-19 vaccine. However, heart transplant patients are still recommended to get vaccinated to acquire protection to some extent [2]. 

Some studies also report that as compared to other patients; heart transplant patients exhibit insufficient antibody response. It means that vaccination does not cause the immune system of heart transplant patients to make enough antibodies against the virus. Therefore, heart transplant patients may still contract the infection even after vaccination [3].

Also, it is not recommended for heart transplant patients to go for routine COVID-19 antibodies testing after vaccination. A negative antibody test shows that vaccination has been ineffective in boosting immunity. 

Should Heart Transplant Patients Receive the Third Dose Of COVID-19 Vaccines?

Regarding the heart transplant and COVID-19 vaccine information, it is recommended that heart transplant patients and immunocompromised patients get a “booster” shot or a “third dose” of the COVID-19 patients. Booster shots will be available for those who have received the Moderna or Pfizer vaccine.

One study suggested that 120 heart transplant patients were given a third dose of mRNA vaccine for three months to check the efficacy and safety of the vaccine. The patients were protected against the COVID-19 infection with improvements in immunogenicity with a third of the mRNA vaccine [4].


It is also important to note that even after the third dose, antibody levels above 100 U per millimeter have been reported in only 55% of heart transplant recipients. Therefore, it is recommended that heart transplant patients, even after receiving the third dose, should maintain protective barrier measures [5]. 

In order to get the third dose of the COVID-19 vaccine, heart transplant patients are suggested to complete their first two doses at least 28 days earlier. Also, vaccines are totally safe and effective for heart transplant patients, and the FDA has also approved their efficacy. 


Heart transplant patients exhibit weak immunity in response to the COVID-19 vaccine because of immunosuppression. The third dose of vaccine is suggested for heart transplant patients to strengthen their immunity against the virus. However, it is recommended to maintain hand hygiene, social distancing, and wearing face masks in public. 


  1. Dash D, Mody R, Ahmed N, Reddy S. Heart transplantation in the time of COVID-19 pandemic. Trends Transplant 2020;13:1–4. https://doi.org/10.15761/tit.1000272.
  2. Boyarsky BJ, Werbel WA, Avery RK, Tobian AAR, Massie AB, Segev DL, et al. Immunogenicity of a Single Dose of SARS-CoV-2 Messenger RNA Vaccine in Solid Organ Transplant Recipients. JAMA – J Am Med Assoc 2021;325:1784–6. https://doi.org/10.1001/jama.2021.4385.
  3. Tchana-Sato V, Ancion A, Tridetti J, Sakalihasan N, Hayette MP, Detry O, et al. Clinical course and challenging management of early COVID-19 infection after heart transplantation: case report of two patients. BMC Infect Dis 2021;21:89. https://doi.org/10.1186/s12879-021-05793-6.
  4. Werbel WA, Boyarsky BJ, Ou MT, Massie AB, Tobian AAR, Garonzik-Wang JM, et al. Safety and Immunogenicity of a Third Dose of SARS-CoV-2 Vaccine in Solid Organ Transplant Recipients: A Case Series. Ann Intern Med 2021;174:1330–2. https://doi.org/10.7326/L21-0282.
  5. Kamar N, Abravanel F, Marion O, Couat C, Izopet J, Del Bello A. Three Doses of an mRNA Covid-19 Vaccine in Solid-Organ Transplant Recipients. N Engl J Med 2021;385:661–2. https://doi.org/10.1056/NEJMc2108861.