Some coronaviruses pose a threat to human health, as illustrated by the 2003 SARS outbreak and the COVID-19 pandemic. Among the coronaviruses that have been thoroughly studied is WIV-1, because it can infect humans. However, WIV-1 is only loosely related to SARS-CoV-2, the virus that causes COVID-19, and thus isn’t responsible for the pandemic.
Epidemiological data show that additional doses of COVID-19 vaccines (“boosters”) lower the risk of getting the disease. The residual DNA in mRNA vaccines, small fragments broken down by enzymes, are leftovers from the manufacturing process. Its amount is within the acceptable range determined by health agencies, which are aware of the phenomenon. No scientific data support the possibility of a potential risk to health of this residual DNA.
When COVID-19 vaccines were first tested, the U.S. Food and Drug Administration had asked that manufacturers demonstrate first and foremost their vaccine’s ability to reduce the risk of getting COVID-19. The Pfizer-BioNTech 2020 clinical trial showed a 95% efficacy in reducing that risk. Furthermore, real-world analysis performed after the worldwide COVID-19 vaccination campaign showed that all-cause mortality was lower among vaccinated individuals.
To date, there have been more than 1.1 million COVID-19 deaths in the U.S. COVID-19 vaccines are highly effective at reducing the risk of severe disease and death. While the COVID-19 vaccines have been linked to potentially serious side effects, such as a particular blood clotting disorder and myocarditis, the risk of blood clots and heart inflammation is higher after COVID-19 than after the vaccines. Overall, the benefits of the COVID-19 vaccines outweigh their risks.
Concerns over the potential health effects of residual DNA in biological products like vaccines aren’t new or unknown to regulatory agencies. In fact, recommended guidelines for acceptable levels of residual DNA were already established by the World Health Organization and the U.S. Food and Drug Administration prior to the COVID-19 pandemic. Vaccines containing DNA, such as the chickenpox vaccine—a live attenuated vaccine containing a DNA virus—have also been widely used before the pandemic and have been shown to be safe.
Like all medical interventions, COVID-19 vaccines can produce side effects. Most of these side effects are mild and short-lived. More serious risks, such as a rare blood clotting disorder and a type of heart inflammation have also been associated with certain COVID-19 vaccines, but are rare. The risk of heart problems and blood clotting, just to name a few, is greater with COVID-19 than with the vaccines. By reducing the risk of infection and severe disease in people, COVID-19 vaccines offer many benefits that go beyond just preventing COVID-associated heart problems. As such, the vaccines’ benefit outweighs their risk.
Misinformation about COVID-19 vaccines harming fertility is a widespread myth that has damaged public trust in the vaccines. While the original vaccine clinical trials didn’t evaluate the effects of COVID-19 vaccines on fertility, scientific studies and safety surveillance data later on have shown that COVID-19 vaccines are safe for pregnant women and don’t cause pregnancy or fertility problems. COVID-19 itself is associated with an increased risk of pregnancy complications, which vaccination can help prevent.
Claims that COVID-19 vaccination is responsible for excess mortality have commonly invoked population-level correlations as supporting evidence. Population-level analyses are relatively easy and quick to do, as the data is readily available. But they come with several caveats, meaning that their results need to be interpreted cautiously. Controlling for confounding factors, such as differences in the age structure of populations and differences in public health measures, is difficult to do with such analyses. Moreover, population-level observations don’t necessarily predict individual-level outcomes.
Several countries have experienced excess mortality since the COVID-19 pandemic. This is likely due to many factors, such as COVID-19 itself, and the strain that the pandemic placed on healthcare systems. However, an analysis of excess mortality over the entire period since the onset of vaccination shows that countries with the highest vaccination rates are the countries with the lowest excess mortality. Data that also accounts for the vaccination status of people who died showed that vaccination doesn’t cause excess mortality.
Available COVID-19 vaccines only use protein fragments of the SARS-CoV-2 virus or genetic information to produce these fragments instead of a full virus. Thus, COVID-19 vaccines cannot replicate in the body nor can they pass from one person to another.
