The future of the one-dose Johnson & Johnson COVID-19 vaccine is uncertain. A Centers for Disease Control and Prevention committee that offers nonbinding advice on vaccine safety would not fully endorse the vaccine, but would not recommend removing it from the pipeline of vaccines yet either.
Instead, the committee wants another week to 10 days to gather more data to see if there is any provable link between the vaccine and a half dozen reports of blood clots that showed up in people who had taken it.
The Advisory Committee on Immunization Practices continued the pause on the distribution of the Johnson & Johnson vaccine to see if more cases of blood clots turn up among people who were vaccinated with it, especially young women. Six cases have been reported out of nearly seven million Americans who have been vaccinated with the Johnson & Johnson drug. Metaphorically speaking, the CDC is wrestling with whether these six cases are a needle in a haystack or the tip of an iceberg.
The committee worked to exercise enough caution to be able to assure the public that the CDC and Food and Drug Administration are certain about the vaccine’s safety but also noted the signal that a longer pause would send to an already skeptical public.
Committee member Dr. Sarah Long said she expects “potentially many more” reports of adverse effects than the rare cases so far reported.
The length of the pause is timed to allow anybody who was recently vaccinated to develop the symptoms that, on average, occurred eight days after vaccination.
Dr. Helen Keipp Talbot said because we have a strong supply of other effective vaccines, “we can be more cautious” about the Johnson & Johnson vaccine than we would be without those alternatives.
Dr. Pablo Sanchez said, “At the current time I am not comfortable continuing vaccinations” with the Johnson & Johnson vaccine.
Dr. Beth Bell said she did not want to vote on whether to allow or disallow the Johnson & Johnson vaccine yet. She said the committee needs a lot more data so it can communicate with the public with a clear statement. “When we say rare, what does that mean?” she said. Later she added, “I do not want to send a message that we have a huge concern” that there is something fundamentally wrong with the Johnson & Johnson vaccine. “It is a very rare event and nothing in life is risk-free, but I want to be able to understand and defend the decision that I’ve made based on a reasonable amount of data.”
Dr. Grace Lee said the role of the committee is to “mitigate risks” involved in vaccinating people versus the benefits of vaccines. She said that while other countries have decided to move forward with vector vaccines even while there are concerns about whether they are connected with clots, it is different from what the U.S. faces since we have other types of vaccines available.
Lee said physicians need to know what to say to patients who might show symptoms of clots since the usual treatment might not apply when the clot is related to a vaccine. Usually, physicians would prescribe a drug called heparin to a patient with clots, but there is some concern that the usual response might cause more harm when the clot is related to a vaccine.
Committee members said repeatedly that the vaccine is both safe and very effective. And they said that the pause should instill confidence in the safety oversight.
Pausing the distribution of the one-dose vaccine causes the most harm to the most vulnerable people, they noted. By that, they mean the hope of the one-dose vaccine was that we could use it to reach populations who might have a difficult time making it to two appointments. The Johnson & Johnson vaccine is also much easier to store and transport, which makes it better suited for rural and far-flung locations.
Yesterday, I covered in some detail the history of concerns over the Johnson & Johnson vaccine and a similar vector vaccine produced by AstraZeneca as well as details about the clots themselves.
The clots in context
We keep hearing that these kinds of blood clots are rare. But how rare?
There is quite a lot of data on this, but some of the data is old. Generally, cerebral venous sinus thrombosis clots — or CVST — show up at a rate of about two to five cases per million people. Other studies say it could be as high as 15 cases per million.
That could mean that the number of clotting cases we have seen out of seven million vaccinated patients is about what we would normally measure in a population. But when you narrow the number of cases observed to a much smaller demographic of young women — and all of the cases reported so far were young women — then the reported ratio of clots to the overall population is way out of whack.
Epidemiologist Katelyn Jetelina adds:
The problem with these numbers, though, is that these numbers are for CVST cases overall. NOT CVST low platelet count (or thrombocytopenia.)
While there are many types of blood clotting events, we’re interested in one specific event: CVST with thrombocytopenia (low blood platelet count). Basically, this event prevents blood from draining out of the brain and causes a brain bleed. And, because of low platelet counts, patients have internal bleeding that can be fatal.
Johnson & Johnson delays rollout in Europe and South Africa
Johnson & Johnson hoped to distribute vaccines in Europe and South Africa this week, but those programs are now on pause, too. South Africa had already administered nearly 300,000 doses with no reported problems.
Denmark drops AstraZeneca vaccine
Denmark has permanently dropped AstraZenica’s vaccine over blood clot concerns. Denmark says it has access to the Pfizer and Moderna vaccines, which should be enough. But if other countries follow suit, it could cause a big hiccup in Europe’s vaccination efforts.
Danish Health Authority Director General Dr. Soeren Brostroem issued a statement saying, “Based on the scientific findings, our overall assessment is there is a real risk of severe side effects associated with using the Covid-19 vaccine from AstraZeneca.” He added, “We have, therefore, decided to remove the vaccine from our vaccination program.”
By the way, the United Kingdom is launching a trial of “mix and match” vaccines in which a person whose first shot was the AstraZeneca vaccine would get a second dose of the Pfizer or Moderna shot.
A plurality, but not majority of Americans plan to vaccinate children as soon as possible
A new Harris poll, gathered before the most recent concerns over the Johnson & Johnson vaccine, shows close to 70% of Americans plan to have their children vaccinated. However, even some of those leaning “yes” say they won’t do so right away. More than one in five adults said they are not sure or do not plan to allow their children to be vaccinated.