The CDC published a paper by Shea and others reviewing this on April 30th.
They found that nearly 8 million doses of the Johnson and Johnson COVID-19 vaccine had been administered and when they reviewed the safety monitoring data, they found that 97% of reported reactions after vaccine received were non-serious, consistent with their preauthorisation clinical trials.
17 thrombotic events with thrombocytopaenia were reported including three non CVST events.
Amongst the 88 deaths reported after vaccination, three occurred in patients with CVST but after a preliminary review, no other deaths appear to have any association with vaccination.
The Johnson and Johnson adenoviral vector vaccine only requires a single dose for substantial protection from COVID-19 and can be stored at refrigerator temperatures.
Because of these advantages, some health authorities and providers have used the Johnson and Johnson COVID-19 vaccine amongst persons for whom ensuring a second dose might be difficult or in settings such as college, campuses or drive through vaccination site where simple storage requirements are important.
It is interesting that the authorities considered the balance between these benefits and the rare but serious safety concern of the risk of thrombosis in large arteries or veins.
On April 23rd 2021 after review of the benefits and risks, they reaffirmed their interim recommendation for use of the Johnson and Johnson COVID-19 vaccine in all persons aged over 18 under the FDA’s emergency authorisation.
They did, however, note that the EUA included a warning for rare clotting events with low platelets primarily occurring amongst women aged 18 to 49 years.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed