Blood Clots and J & J’s COVID-19 vaccines


Day 384: Stay Safe Minnesota

The reported occurrence of blood clots in patients receiving the J & J’s COVID-19 vaccine is extremely rare. Obviously the vaccines are tremendously safe. We are talking about six events in 6.85 million doses administered.

In the Washington Post, health reporters Lenny Bernstein and Allyson Chiu write quoting federal health officials and patients that although extremely rare but serious form of blood clot in the brain suffered by six women who received Johnson & Johnson’s coronavirus vaccine.

Obviously the vaccines are tremendously safe. We are talking about six events in 6.85 million doses administered.

Dr. Peter Marks, director of the Center for Biologics Evaluation and Research at the FDA (source: USA Today)
  • Blood Clot: The Washington Post reports that blood clot symptoms include “headaches, leg pain, abdominal pain and shortness of breath that begins six to 13 days after receipt of the vaccine. Those symptoms are different from the much more common flu-like aches and lethargy that can occur a day after receiving the shot, which are generally harmless side-effects of inoculation against the coronavirus.”
  • Cerebral Venous Sinus Thrombosis: All the six reported cases of blood clot after J & J vaccine included “cerebral venous sinus thrombosis had low platelet counts, leading experts to speculate that the vaccine somehow, activates platelets and leads to blood clots in the channels that help route blood away from the brain. The clots can cause strokes or similar damage to the brain,” according to the Post.

Peter Marks, director of the Center for Biologics Evaluation and Research (CBER) at the Food and Drug Administration reportedly told “if someone ends up with a very severe headache or any kind of shortness of breath, pain in their legs, pain in their abdomen … they would want to seek medical attention, and if there are low platelets at that time”.

In the USA Today, Karen Weintraub writes that scientists are beginning to understand the rare blot symptoms. Dr. Theodore  Warkentin, who co-wrote an April 9 paper describing unusual blood clotting conditions in 11 patients who received the AstraZeneca-Oxford vaccine, told USA Today “though difficult to directly connect a serious health problem with a vaccine, but with the J&J and AstraZeneca-Oxford vaccines, ‘there is a smoking gun‘”.

Dr. Warkentin and his colleagues named the condition vaccine-induced immune thrombotic thrombocytopenia, or VITT, writes the USA-Today.

Vaccine-induced Immune Thrombotic Thrombocytopenia

Warkentin & colleague believe that it is similar to a rare problem seen either in patients recovering from surgery or from those on heparin too. “In all cases, the immune system creates antibodies that activate platelets in the bloodstream. The platelets, which normally promote wound healing, end up clumping and causing blood clots, often in the brain.”

“That also leads to low levels of platelets circulating in the bloodstream, which is called thrombocytopenia.”

When they Likely Occur: The VITT symptoms “seems to occur five to 13 days after vaccination with the J&J or AstraZeneca-Oxford shots – after the normal vaccine side effects have abated”.

The CNN’s Jacqueline Howard writes in the April 14 Coronavirus Updates that according to a top official at the Johnson & Johnson’s coronavirus vaccine, at least one vaccine trial volunteer also developed unusual blood clots after the vaccine.

Blood clots were seen in two patients in Phase 3 vaccine trials – one who got vaccine and one who was given a placebo shot.

Dr. Aran Maree, chief medical officer for J&J’s vaccine arm Janssen (souce: CNN)

“There was one case of the concerning type of blood clot, known as cerebral venous sinus thrombosis (CVST), in September, during the Phase 3 trial of the single-dose vaccine. It involved a 25-year-old white man who has recovered. Plus, a 59-year-old woman developed a series of blood clots known as deep vein thromboses or DVTs,” Maree told to CNN.

“There is also an ongoing study, a large open label study, in South African health care professionals. This has enrolled currently, 272,438 participants. We have had no reports of CVST. We have had one case of pulmonary embolism.”

Vaccines and Blood Clots Not Yet Clear

According to the US Centers for Disease Control and Prevention (CDC) vaccine experts, “it’s not yet clear whether blood clots seen after people got the AstraZeneca and Johnson & Johnson vaccines are the same”.

The extent to which the cases seen after each of these adenoviral vector vaccines represent exactly the same syndrome is not entirely clear at this time.

CDC’s Dr. Beth Bell told the meeting (source: CNN)

“Similar blood clots were seen in Europe and the UK after people got AstraZeneca’s vaccine, which is not authorized in the US. Both vaccines use common cold viruses called adenoviruses to carry genetic material from the coronavirus into the body and elicit immunity,” writes CNN’s Maggie Fox.

On Wednesday, the CDC’s panel of vaccine experts concluded their meeting without any recommendation. “They did not have enough information to recommend changes in their recommendations, or even to suggest extending a pause in administering the vaccine”.

“We will find a time to reconvene. We will try to identify what that date is by Friday of this week so that people have a little bit more time to get it on the calendars,” Dr. Amanda Cohn, ACIP executive secretary told the meeting.

Coronavirus-19 vaccination watch

According to the US Centers for Disease Control and Prevention (CDC) COVID vaccination tracker page (as of Apr 15, 9 a.m.) 255,400,665 doses have been distributed and 198,317,040 doses administered. According MDH COVID-19 Response vaccine data (as of April 13) a total of 3,466,394 doses of Covid-19 (Pfizer & Moderna) vaccines have been administered in Minnesota. According to the MDH latest tally (as of Apr 15) the confirmed COVID-19 cases in Minnesota are 549,830 (out of 8,711,467 tested) with 6,989 deaths.