The International Society for Vaccines held its 6th and final COVID-19 Vaccines Virtual Congress on May 25, 2021. The sessions covered a variety of topics, including learning more about the Janssen vaccine, the Novavax vaccine, and hypersensitivity events related to the mRNA vaccines.
In one session, Hanneke Schuitemaker, PhD, Head of Viral Vaccine Discovery and Translational Medicine and Disease Area Stronghold Leader for Viral Vaccines at Janssen Vaccines & Prevention BV, a subsidiary of Johnson & Johnson, discussed key findings on the vaccine efficacy of the company, including 66% efficacy against moderate to severe/critical COVID-19 in all countries where it was tested, as well as 85% efficacy against severe COVID-19 worldwide. In addition, the vaccine provided complete protection against COVID-19-related hospitalizations with no deaths in the group that received the vaccine. She also discussed the side effect of thrombosis with thrombocytopenia syndrome that led to a temporary pause in vaccine use in the United States. The cases occurred in women ages 18 to 59, and the onset of symptoms was 6 to 15 days after receiving the vaccine. To address the concerns, the company has updated the labeling of the vaccines and has worked with public health organizations to raise awareness of the side effect to improve diagnosis and treatment initiation. The company is continuing a two-dose trial to determine if it would have greater efficacy and results are expected in the third quarter. Pediatric studies and studies in pregnant women are discussed.
In another session, Greg Glenn, MD, the president of research and development at Novavax, Inc., discussed the company’s vaccine results in Phase III trials in the United Kingdom, as well as the ongoing trial in the United States and Mexico. In the UK study, the vaccine was found to be 89.7% effective overall and 96% effective with the original disease strain, as well as 86.3% effective in cases with the Alpha variant, previously known as the B.1.1 .7 variant, which had become the predominant strain of the disease during the trial. In the ongoing trial in the United States and Mexico, the study has approximately 30,000 participants who are a representative sample of the population. Novavax, Inc. expects to file for authorization with the U.S. Food and Drug Administration in the third quarter of 2021. A pediatric study involving approximately 3,000 teens began in late April 2021. The side effects are generally tenderness and pain at the injection site and were often mild. To address the issues of variants, the company is looking at several approaches, including boosters with variants or a bivalent approach.
For the final session, Mariana Castells, MD, PhD, a clinician, researcher, and educator at Brigham and Women’s Hospital, discussed the hypersensitivity events associated with the Pfizer/BioNTech and Moderna vaccines. The first 2 reactions occurred with the Pfizer/BioNTech vaccine in 2 female health professionals in the UK with known food and drug allergies who were carrying EpiPens. The Moderna vaccine was found to cause similar reactions when a doctor in Massachusetts with a known seafood allergy had an anaphylactic reaction. Research indicates that polyethylene glycols and polysorbates in the vaccines may be the culprit behind these reactions and skin testing for this hypersensitivity may be helpful. Anaphylaxis is a rare occurrence after receiving a dose of the vaccine, and there have been no fatalities so far. The response is rapid and likely occurs in the 15 minutes that a person has to wait at the vaccination site for safety reasons. It seems to be much more common in women than in men. In addition, there are no contraindications to vaccination if there is a history of previous allergies, anaphylaxis or mast cell activation disorders.