Paper and Threads

Evaluating a Headache After Vaccination with J and J and AstraZeneca Vaccines:  The rare clotting adverse event after vaccination with one of the two adenovirus viral vaccine vaccines is now being called vaccine-induced thrombotic thrombocytopenia (VITT).  I am a retired hematologist and have evaluated many patients with blood clots - venous and arterial - and in general the development of a cerebral venous sinus thrombosis (CVST) in very rare.  But the US Vaccine Adverse Effect Reporting System (VAERS) for monitoring vaccine safety demonstrated 6 cases, all associated with low platelets. This combination resembles a heparin side effect known as Heparin-Induced Thrombocytopenia (HIT) - in which patients on heparin develop antibodies to a complex known as heparin-PF4 (platelet factor 4).  I spent the first 15-20 years, after my training, in a lab purifying, characterizing, and then measuring PF4. Since then a test has been developed to measure the heparin-PF4 antibodies in patients with HIT.  Now these tests are found to also be positive in patients with VITT following the J and J and AstraZeneca vaccines, even though none received heparin 

Some Risk Factors for any Clots: OCP, pregnancy, malignancy, smoking, immobility, inherited disorders.  

Risk Factors for CVST: J and J Vaccine: 1 per million;  Covid-19 4-20 per 100,000; pregnancy 10-20 per 100,000 deliveries; oral contraceptives 2.7-40 per 100,000 people, and General Population: 3-15 per million per year.

The risk factors and incidence for development of CVST shows that the incidence for VITT is substantially less than the incidence in patients with Covid-19.  With the current data, the risk vs benefit ratio warrants continuation of J and J vaccinations, maybe to select age groups.  

The CDC-FDA still have a PAUSE on J and J vaccinations - to carefully study any patients that may develop clots within 3 weeks after their vaccination that was before the pause.  Patients who develop severe headaches, abdominal pain, leg pain or shortness of breath should see a physician and have an evaluation - including a platelet count and a PF4 antibody test.  Under no circumstances should patients with clot, low platelets, and a positive PF4 test be treated with heparin - instead consult a hematologist for alternate treatments.   

Posted by Shirley at 6:31 AM | Permalink | Comments (0)

Yesterday we learned that there would be a PAUSE in the administration of the Johnson and Johnson vaccine in order for the CDC and FDA to carefully review 6 cases of unusual blood clots associated with thrombocytopenia (decreased platelets).  The blood clot is in the veins of the brain (called central venous sinus thrombosis - CVST) or even more rarely in the veins in the abdomen.  The CDC and FDA together decided to PAUSE while they carefully studied these patients, one of whom died. The incidence of this type of clot in unvaccinated patients is 2-14 per million patients,  In this study there were 6 cases in almost 7 million J & J vaccinations in the US. or a risk of 1 per million.  What makes this CVST different is the severely decreased platelet count that occurs with it. 

Patients with CVST develop severe headaches, abdominal pain, leg pain, or shortness of breath and should consult a physician. This is not the flu-like headache seen 1-2 days after vaccination. The 6 women were between the ages of 18-48 and the onset of the thrombosis occurred 6-13 days after the vaccination.  A complete blood count should be done in addition to imaging studies to identify the clot and document the decreased platelet count.  Patients with venous clots are usually treated with heparin, but it is contraindicated in these patients - which is one of the reasons that the CDC and FDA wanted to PAUSE the vaccinations so physicians could be alerted to the possible diagnosis and correct treatment.  See Below

Scientists want to see if they can identify any underlying risk factors, or specific patient groups that should not get the J&J vaccine.    Oral Contraceptive drugs did not seem to be the common factor.  At this time it appears as if this syndrome is due to the development of autoimmune antibodies, which activate the platelets and cause clotting.  These same types of clots, with thrombocytopenia, is also found after the AstraZeneca vaccines and groups of scientists here and abroad are already studying these events and changes in the coagulation system.  Note: both the J and J vaccine and Oxford-AstraZeneca vaccines use a harmless adenovirus to carry the spike protein DNA into cells so spike protein can be made and stimulate an immune response.  Pfizer and Moderna are messenger RNA vaccines - a different platform for vaccine production. 

Posted by Shirley at 7:09 AM | Permalink | Comments (0)

More Good News!  This week Moderna published antibody levels measured over 6 months after the 2nd dose in their Phase 1 trial and they were excellent and durable.  All of the tests were done at NIH-NIAID.  These were the volunteers that participated in the very first human studies.  Phase 1 clinical vaccine trials are done to assess safety and to establish a dose range that produces a good antibody response.  Now this small patient group has been observed and their antibody production measured regularly for just over 6 months from their vaccination.  In contrast, Phase 3 clinical vaccine studies assess the ability of vaccination to prevent symptomatic infection in vaccinated subjects compared to subjects given placebo - and then vaccine efficacy is calculated. 

In the current report antibody production to the "spike proteins" and the efficacy of the subjects serum to neutralize the virus was assessed serially by 3 different types of tests on 33 volunteers over a 6 month period.  There were 3 age groups tested: 18-55 years, 56-70 years, and 71+ years.  There was an excellent antibody response in all subjects and it remained high over 6 months in all age groups, although the amount of antibodies decreased with advancing age.  The antibody amounts that best correlate with vaccine efficacy are not currently known, but this patient cohort will continue to be monitored, and will even be given a booster dose to assess its effect on antibody production against the virus and the variants.   Even more good news: see below.

Yesterday Pfizer submitted a request to the FDA to extend their EUA for approval of their vaccine for 12-15 year old children.   There were ~2000 children studied and there was an immune response in 100% of the children.  Antibody levels were even higher than in older groups. That means 3 more of our grandchildren will be eligible!

Posted by Shirley at 6:41 AM | Permalink | Comments (0)

There was a CDC Vaccination Study Published in the Morbidity and Mortality Weekly Report from April 2 - and the results are very encouraging.  Health Care Workers, 1st responders, and other essential/frontline workers (N=3950 subjects) were randomized between Moderna/Pfizer vaccinations and placebo.  Eight locations in 6 states participated in the Heroes-Recover study from Dec. 14, 2020 to Mar. 13, 2021 (AZ, FL, MN, OR, TX, and UT).  The subject ages included 72% 18-49 years and 28% >50. 

All of the subjects were Covid-19 PCR test negative prior to their vaccinations and then a  nasal swab Covid-19 PCR test was repeated weekly for 13 weeks and if they developed symptoms during that time. The symptoms surveyed include fever, chills, cough, shortness of breath, sore throat, diarrhea, myalgias, and/or loss of taste or smell.  The Phase 3 Clinical Trials for both vaccines studied volunteers when they developed symptoms and this study provides data for the protection against asymptomatic and symptomatic subjects.  Thirty-one percent had at least 1 comorbidity.  See Below for Results

The Good News:  Subjects who were >2 weeks following their 2nd dose (N=2470 subjects) had 90% efficacy preventing symptomatic and asymptomatic Covid-19 compared to placebo.  For those that were >2 weeks after just a single dose (N=477 subjects) had an efficacy of 80%. 

Posted by Shirley at 6:49 AM | Permalink | Comments (0)

Great News!  Pfizer just updated their Covid Vaccine Phase 3 clinical trial data after 6 months.  This information was published in a company press release.  They found 927 cases of symptomatic and confirmed cases of Covid-19 in their clinical trial subjects- 850 cases in the placebo group and 77 in the vaccinated group - for an efficacy of 91.3%  Protection against severe disease in vaccinated subjects was 100% using the CDC criteria (32 cases) and 95.3% using the FDA criteria of severe disease (21 cases).  There were safety data on more than 12,000 vaccinated subjects who were followed for at least 6 months after their 2nd dose and the safety profile was still favorable.  These data will make it possible to apply for a Biologic License Approval (BLA) from the FDA - based on their 6 month safety follow-up.  A BLA is required for commercial advertising and distribution. 

In the US trial there were 647 Covid cases in the placebo group, 50 in the vaccine group for an efficacy of 92.6%  In the S. African trial of about 800 volunteers there were 9 cases of Covid-19 in the placebo group, 6 of whom had the S. African variant.  There were no safety issues in the full trial of approximately 44,000 volunteers.  All vaccinated volunteers will be followed for a full 24 months to collect additional data. Read Below 

The Pfizer vaccine EUA was granted one week before the Moderna vaccine, so we may see the 6 month followup data for the Moderna vaccine shortly.  One of the requirements for submitting an application for a BLA is having 6 months of follow-up safety data.  The Moderna trial will also be carried out for a full 24 months.  This is deemed important for all clinical trials because very rare side effects could still be seen.

Posted by Shirley at 6:51 AM | Permalink | Comments (1)