Why should I trust the COVID-19 (Coronavirus Disease 2019) vaccine?

COVID-19 Vaccine Trust: Evidence-Based Rationale

COVID-19 vaccines should be trusted because they demonstrate a highly favorable benefit-to-risk ratio, with substantial evidence showing they effectively reduce hospitalizations, severe disease, and deaths while maintaining an excellent safety profile. 1

Effectiveness of COVID-19 Vaccines

• COVID-19 vaccines provide significant protection against severe COVID-19–associated illness and death, with the Advisory Committee on Immunization Practices (ACIP) recommending vaccination for all persons aged ≥6 months 1
• Vaccine effectiveness against COVID-19–associated hospitalization is substantial, with studies showing 44% (95% CI = 34%–52%) effectiveness against hospitalization and 23% (95% CI = 8%–36%) effectiveness against death 1
• For adults without immunocompromising conditions, vaccine effectiveness against hospitalization was 49% (95% CI = 43%–55%) within 7–59 days after vaccination 1
• Protection against critical illness is more durable, with 69% (95% CI = 57%–78%) effectiveness 7–59 days after vaccination 1

Favorable Benefit-to-Risk Ratio

• For every 1 million males aged 12-29 years (the highest risk group for myocarditis) who receive a COVID-19 mRNA vaccine, only 39-47 cases of myocarditis would be expected, while 560 hospitalizations, 138 ICU admissions, and 6 deaths would be prevented 1
• Most reported systemic reactions to vaccines have been mild and transient, with adverse cardiovascular effects in clinical trials being largely isolated with an incidence of <0.05% 1
• Serious adverse event rates are rare for mRNA vaccines, with anaphylaxis occurring in only 2.5-4.7 cases per million doses and myocarditis in 3.5 cases per million doses 1

Protection for Vulnerable Populations

• COVID-19 vaccination is especially important for vulnerable populations who face higher risks of severe outcomes, including older adults, those with underlying medical conditions, and immunocompromised individuals 1
• Five non-randomized studies support the benefit of vaccination in reducing the risk of severe COVID-19 illness in patients with cancer, with vaccinated individuals significantly less likely to experience hospitalization or death compared to unvaccinated individuals 1
• During October 2023–May 2024, U.S. COVID-19–associated hospitalization rates were highest among adults aged ≥75 years, followed by infants aged <6 months and adults aged 65–74 years, highlighting the importance of vaccination for these groups 1

Safety Profile

• The vast majority of adverse events after COVID-19 vaccination are mild to moderate (grade 1 or 2), with the most common side effects being injection site pain, fatigue, myalgia, headache, and fever 1
• Vaccine Safety Datalink (VSD) surveillance has continuously monitored for adverse events, with most signals being thoroughly investigated and not showing consistent evidence of safety problems 1
• Cases of vaccine-associated myocarditis have been mild and transient, with no cases having associated thrombotic events, thrombocytopenia, or disseminated intravascular coagulation 1

Durability of Protection

• While vaccine effectiveness may wane over time, protection against severe outcomes remains strong 2
• Studies have shown limited waning in vaccine effectiveness against COVID-19-related hospitalization and death at 20 weeks or more after vaccination 2
• Updated vaccine formulations are developed to target currently circulating SARS-CoV-2 strains, providing additional protection as the virus evolves 1

Scientific Consensus

• Multiple high-quality studies consistently demonstrate that COVID-19 vaccines are effective in preventing severe disease, hospitalization, and death 3, 4, 5
• The American College of Cardiology, Advisory Committee on Immunization Practices, and other leading medical organizations strongly support COVID-19 vaccination based on the evidence of benefits outweighing risks 1

Important Considerations

• Vaccine effectiveness varies by age, underlying conditions, and time since vaccination, with older adults and those with certain medical conditions potentially needing more careful consideration for timing of vaccination 2
• While rare adverse events have been reported, the risk of severe outcomes from COVID-19 infection far exceeds the risk of vaccine-related adverse events across all age groups 1
• Continued adherence to preventive measures may still be necessary even after vaccination, especially for those at highest risk 1

The evidence overwhelmingly supports that COVID-19 vaccines are safe and effective tools to prevent severe COVID-19, hospitalization, and death against all variants of concern. The benefits of vaccination substantially outweigh the risks, making COVID-19 vaccines worthy of trust.