The dangers of pausing the J&J vaccine

The rapid development of several effective vaccines is one of the few scientific success stories of the COVID-19 pandemic. Unfortunately, the recent “pause” on using the Johnson & Johnson vaccine will dampen the impact of this success. Many older people are still waiting for the vaccine, both here and abroad. The pause will unnecessarily reduce the supply of vaccines, leading to additional deaths.

Before the pandemic, I helped design parts of the system that the U.S. Centers for Disease Control and Prevention (CDC) use to detect and evaluate vaccine side effects. Once a side effect has been identified, public health scientists and regulators must also consider the disease’s risk and harms and patient characteristics.

Early this week, the CDC/FDA Vaccine Adverse Event Reporting System (VAERS) detected an increased risk of cerebral venous sinus thrombosis (CVST) for the J&J vaccine. CVST is a very rare but serious condition where blood clots form in the brain. If not properly treated, it can lead to death. VAERS found six women diagnosed with CVST after vaccination, all below the age of 50.

With more than six million J&J doses administered, CVST is a very rare adverse reaction at around one per 1 million doses, but that number is misleading. The risk is higher for those under 50, who are better off receiving the Pfizer or Moderna vaccines. Even though many more patients have received those vaccines, no CVST safety problems have been linked to them.

The policy should be different for the older population, for which there were no reported cases of CVST. To deny the J&J vaccine to older people is neither desirable nor necessary. With a pause for all ages, the total vaccine supply will decrease, delaying vaccinations and increasing COVID-19 mortality.

While anyone can get infected, there is more than a thousand-fold difference in the risk of COVID-19 mortality between the old and the young. The older population – for whom this disease is particularly deadly – needs this vaccine. We need to vaccinate them as quickly as possible, not only in the United States but worldwide.

It may seem strange to have different vaccine recommendations for different ages, but that is common. One example is the combined measles-mumps-rubella-varicella (MMRV) vaccine. It was originally recommended for children at ages 1 and 5. When the CDC’s Vaccine Safety Datalink system detected an increased risk of febrile seizures among the one-year-olds but not the five-year-olds, the vaccine’s recommended use changed. The vaccine is now commonly given to older children, while it is no longer recommended for the younger ones.

Including older people in the pause for the J&J vaccine also creates a problem in public health messaging. Many people will naturally draw the erroneous conclusion that the vaccine may not be safe for anyone. This will inevitably lead some older people to lower their confidence in the vaccine even if the “pause” is eventually lifted.

During this last year, vaccine confidence has been damaged by questionable public health messaging. For instance, former CDC director Robert Redfield said that masks may offer more protection than vaccines against the virus. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has asserted that those fully vaccinated must continue to wear masks and physically distance, even though the vaccines provide excellent protection. Some governors and universities have pushed to introduce coercive vaccine passports and mandates, leading many to ask, “If the vaccine is so good, why am I being forced to get it?”

The COVID-19 vaccines provide excellent protection, and we cannot afford more such unwarranted vaccine skepticism.

Martin Kulldorff is a professor of medicine at Harvard Medical School.