Another reversal in thinking may be imminent. Some scientists have raised concerns that the safety risks of Covid-19 vaccines have been underestimated. But the politics of vaccination has relegated their concerns to the outskirts of scientific thinking—for now.
Historically, the safety of medications—including vaccines—is often not fully understood until they are deployed in large populations. Examples include rofecoxib (Vioxx), a pain reliever that increased the risk of heart attack and stroke; antidepressants that appeared to increase suicide attempts among young adults; and an influenza vaccine used in the 2009-10 swine flu epidemic that was suspected of causing febrile convulsions and narcolepsy in children. Evidence from the real world is valuable, as clinical trials often enroll patients who aren’t representative of the general population. We learn more about drug safety from real-world evidence and can adjust clinical recommendations to balance risk and benefits.
The Vaccine Adverse Event Reporting System, or Vaers, which is administered by the Centers for Disease Control and Prevention and the Food and Drug Administration, is a database that allows Americans to document adverse events that happen after receiving a vaccine. The FDA and CDC state that the database isn’t designed to determine whether the events were caused by a vaccine. This is true. But the data can nonetheless be evaluated, accounting for its strengths and weaknesses, and that is what the CDC and FDA say they do.
The Vaers data for Covid-19 vaccines show an interesting pattern. Among the 310 million Covid-19 vaccines given, several adverse events are reported at high rates in the days immediately after vaccination, and then fall precipitously afterward. Some of these adverse events might have occurred anyway. The pattern may be partly attributable to the tendency to report more events that happen soon after vaccination.
The database can’t say what would have happened in the absence of vaccination. Nonetheless, the large clustering of certain adverse events immediately after vaccination is concerning, and the silence around these potential signals of harm reflects the politics surrounding Covid-19 vaccines. Stigmatizing such concerns is bad for scientific integrity and could harm patients.
Four serious adverse events follow this arc, according to data taken directly from Vaers: low platelets (thrombocytopenia); noninfectious myocarditis, or heart inflammation, especially for those under 30; deep-vein thrombosis; and death. Vaers records 321 cases of myocarditis within five days of receiving a vaccination, falling to almost zero by 10 days. Prior research has shown that only a fraction of adverse events are reported, so the true number of cases is almost certainly higher. This tendency of underreporting is consistentent with our clinical experience.
Analyses to confirm or dismiss these findings should be performed using large data sets of health-insurance companies and healthcare organizations. The CDC and FDA are surely aware of these data patterns, yet neither agency has acknowledged the trend.
The implication is that the risks of a Covid-19 vaccine may outweigh the benefits for certain low-risk populations, such as children, young adults and people who have recovered from Covid-19. This is especially true in regions with low levels of community spread, since the likelihood of illness depends on exposure risk.
And while you would never know it from listening to public-health officials, not a single published study has demonstrated that patients with a prior infection benefit from Covid-19 vaccination. That this isn’t readily acknowledged by the CDC or Anthony Fauci is an indication of how deeply entangled pandemic politics is in science.
There are, however, signs of life for scientific honesty. In May, the Norwegian Medicines Agency reviewed case files for the first 100 reported deaths of nursing-home residents who received the Pfizer vaccine. The agency concluded that the vaccine “likely” contributed to the deaths of 10 of these residents through side effects such as fever and diarrhea, and “possibly” contributed to the deaths of an additional 26. But this type of honesty is rare. And it is rare for any vaccine to be linked to deaths, so this unusual development for mRNA vaccines merits further investigation.
The battle to recover scientific honesty will be an uphill one in the U.S. Anti-Trump politics in the spring of 2020 mushroomed into social-media censorship. News reporting often lacked intellectual curiosity about the appropriateness of public-health guidelines—or why a vocal minority of scientists strongly disagreed with prevailing opinions. Scientists have advocated for or against Covid-19 therapies while having financial relationships with product manufacturers and their foundation benefactors.
Public-health authorities are making a mistake and risking the public’s trust by not being forthcoming about the possibility of harm from certain vaccine side effects. There will be lasting consequences from mingling political partisanship and science during the management of a public-health crisis.
Dr. Ladapo is an associate professor of medicine at UCLA’s David Geffen School of Medicine. Dr. Risch is a professor of epidemiology at Yale School of Public Health.