COVID-19 Vaccination in Adults with Congenital Heart Disease

Quick Takes

  • With the COVID-19 vaccine rollout, it is important to identify and prioritize access for patients at the highest risk of severe illness.
  • In congenital heart disease, a decompensated physiologic state, not necessarily anatomic complexity, makes moderate to severe disease more likely.
  • It is prudent that clinicians make time to educate their patients, especially those at highest risk, to obviate public safety concerns and skepticism.

COVID-19 has had a devastating global impact, with over 110 million persons infected and 2.4 million deaths to date.1 While the burden of the pandemic is incalculable, it has resulted one major scientific achievement: the fastest creation and approval of an effective vaccine ever seen. With an end-goal of vaccinating the entire eligible United States (US) population, The Centers for Disease Control and Prevention created a phased rollout plan that first prioritizes the elderly and those individuals at the highest risk of exposure to, or severe illness from, COVID-19. Many adults with acquired cardiovascular disease and adult congenital heart disease (ACHD) patients fall into a medically high-risk group. To best identify those patients at the highest cardiovascular risk of severe illness, the ACC has released a Heath Policy Statement on Cardiovascular Disease Consideration for COVID-19 Vaccine Prioritization.2

Current Vaccine Landscape

Two vaccines, manufactured by Pfizer-BioNTech and Moderna, have received Emergency Use Authorization by the US Food and Drug Administration. Both are two-dose series with excellent efficacy. In Phase 3 trials, the Pzifer-BioNTech vaccine (n=43,449) conferred 95% protection, and the Moderna vaccine (n=30,420) 94.1% protection, from infection. Equally important is that subjects who become infected with COVID-19 despite being fully vaccinated experience substantial protection from severe illness.3,4 Pfizer-BioNTech is currently approved in persons ≥16 years old, and Moderna ≥18 years old. Details on the other vaccine candidates currently under investigation can be found at:

It is vitally important that clinicians make time to educate their patients on these vaccines, as this rapid vaccine production has been met with public safety concerns and skepticism. Both vaccines are highly reactogenic, eliciting a strong immune response. Minor side effects are common, particularly after the second dose, and include injection site pain, fever, headache, chills, myalgia, and fatigue.3-5 Severe reactions are uncommon, though available data at this time can only speak towards short-term safety issues. Vaccination of the population at large has the potential to reveal previously unknown rare side effects.5 Anaphylactic reaction is extremely rare, with rates reported at 4.7 cases per million doses for the Pfizer-BioNTech vaccine and 2.5 cases per million doses for the Moderna vaccine.6 Patients with a prior severe allergic reaction to any of the vaccine components should not receive the COVID-19 vaccine. Misconceptions about the vaccines should be addressed and may include concerns over the vaccination causing COVID-19 infection and that receiving the vaccine may worsen a patient's underlying heart disease. Patients with a history of COVID-19 infection should also be educated on the necessity of vaccination for potentially longer-lasting immunity.

How Do ACHD Patients Fit into the Prioritization Schedule?

The ACHD population is extremely heterogeneous. Disease severity has traditionally been classified with an emphasis on anatomic complexity. The 2018 AHA/ACC ACHD Guidelines introduced a novel classification system based on a combination of anatomic and physiologic characteristics.7 The addition of physiologic staging adds greater insight into a patient's functional status and active hemodynamic issues (Table 1).

Table 1

Stage A Stage C
NYHA FC I symptoms

No hemodynamic or anatomic sequelae
No arrhythmias
Normal exercise capacity
Normal renal/hepatic/pulmonary function
NYHA FC III symptoms

Significant (moderate or greater) valvular disease; moderate or greater ventricular dysfunction (systemic, pulmonic, or both)
Moderate aortic enlargement
Venous or arterial stenosis
Mild or moderate hypoxemia/cyanosis
Hemodynamically significant shunt
Arrhythmias controlled with treatment
Pulmonary hypertension (less than severe)
End-organ dysfunction responsive to therapy
Stage B Stage D
NYHA FC II symptoms

Mild hemodynamic sequelae (mild aortic enlargement, mild ventricular enlargement, mild ventricular dysfunction)
Mild valvular disease
Trivial or small shunt (not hemodynamically significant)
Arrhythmia not requiring treatment
Abnormal objective cardiac limitation to exercise
NYHA FC IV symptoms

Severe aortic enlargement
Arrhythmias refractory to treatment
Severe hypoxemia (almost always associated with cyanosis)
Severe pulmonary hypertension
Eisenmenger syndrome
Refractory end-organ dysfunction
Table 1. AHA/ACC physiologic classification of ACHD patients. Adapted from Stout et al.7

The ACC recommends that ACHD patients at an advanced, decompensated physiologic stage be considered among the highest risk cardiac patients and prioritized for vaccination. In a single-center cohort of 53 CHD patients with COVID-19 infection (10 pediatric, 43 adults), advanced physiologic stage (C or D), but not increasing complexity of anatomy, was associated with an increased odds of having moderate or severe illness (OR 19.38, p=0.002).8 Thus, a single ventricle patient post-Fontan palliation with excellent intracardiac hemodynamics may fare better than a repaired tetralogy of Fallot patient with significant valve regurgitation or profound ventricular dysfunction. A large-scale multicenter study launched through a collaborative effort between Adult Congenital Heart Association (ACHA) and the International Society for Adult Congenital Heart Disease is currently underway. Preliminary findings shared at a recent ACHA webinar offer support to the ACC recommendation to prioritize physiologic stage C and D patients.

The Fight Against COVID-19 Continues

Vaccination remains only part of the solution. Approximately 17.9 million people in the US, 5.4% of the population, have been fully vaccinated. Another 24.8 million (7.6% of the population) have received an initial vaccine dose.9 Population immunity to COVID-19 transmission and infection is not likely to be achieved until at least 67% of the US population is vaccinated.5,10 At the same time, new strains of COVID-19, for which the current vaccines may be less efficacious, are becoming increasingly prevalent. Wearing facemasks, hand washing, and social distancing remain crucial to slowing viral spread and for protecting our patients and ourselves from infection. We will get through this together and must continue to support each other to get across the finish line.


  1. Coronavirus Disease (COVID-19) Dashboard (World Health Organization website). 2021. Available at: . Accessed 02/21/2021.
  2. Driggin E, Morris AA, Maddox TM, et al. ACC health policy statement on cardiovascular disease considerations for COVID-19 vaccine prioritization. J Am Coll Cardiol 2021;Feb 9:[Epub ahead of print].
  3. Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine. N Engl J Med 2020;383:2603-15.
  4. Baden LR, El Sahly HM, Essink B, et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N Engl J Med 2021;384:403-16.
  5. Connors M, Graham BS, Lane HC, Fauci AS. SARS-CoV-2 vaccines: much accomplished, much to learn. Ann Intern Med 2021;Jan 19:[Epub ahead of print].
  6. Shimabukuro TT, Cole M, Su JR. Reports of anaphylaxis after receipt of mRNA COVID-19 vaccines in the US—December 14, 2020-January 18, 2021. JAMA 2021;Feb 12:[Epub ahead of print].
  7. Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC guideline for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2019;73:1494-1563.
  8. Lewis MJ, Anderson BR, Fremed M, et al. Impact of Coronavirus Disease 2019 (COVID‐19) on patients with congenital heart disease across the lifespan: the experience of an academic congenital heart disease center in New York City. J Am Heart Assoc 2020;9:e017580.
  9. COVID Data Tracker 2021 (CDC website). 2021. Available at: . Accessed 02/21/2021.
  10. Fontanet A, Cauchemez S. COVID-19 herd immunity: where are we? Nat Rev Immunol 2020;20:583-84.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, COVID-19 Hub, Invasive Cardiovascular Angiography and Intervention, Prevention, Cardiac Surgery and Arrhythmias, Cardiac Surgery and CHD and Pediatrics, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Interventions, CHD and Pediatrics and Quality Improvement, Interventions and Structural Heart Disease

Keywords: Heart Defects, Congenital, COVID-19, Coronavirus, Coronavirus Infections, severe acute respiratory syndrome coronavirus 2, Pandemics, Vaccination, Vaccines, Cardiovascular Diseases, Anaphylaxis, Fontan Procedure, United States Food and Drug Administration, Myalgia, Hand Disinfection, Tetralogy of Fallot, Risk Factors, Immunity, Ventricular Dysfunction, Centers for Disease Control and Prevention, U.S., Hemodynamics, Severity of Illness Index

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