It warned that though the chances of occurrence were very low, people ought to be aware of the symptoms so that they could seek prompt medical treatment to help recovery and avoid complications. The EMA has categorised thrombocytopenia (drop in platelet level) alone as “common”, which means the occurrence could be from one in 100 persons to lesser than one in 10 and the occurrence of thrombocytopenia in combination with thrombosis (clotting) as “very rare”, which means it may affect less than one in 10,000 vaccinated persons.
AstraZeneca, which has licensed the same vaccine to Serum Institute in India, has also updated it package leaflet, which included warnings and precautions about blood disorders or very rare blood clots in unusual locations ( brain, bowel, liver, spleen) in combination with low level of blood platelets following vaccination.
“A very rare type of thrombosis could happen in veins on the surface of the brain, veins that supply the intestines and in arteries,” said the EMA.
“Most of the cases reported so far have occurred in women under the age of 60 years. Most cases occurred within two weeks of the person receiving their first dose. There is limited experience with the second dose,” said a statement put out by the EMA, adding that some cases had a fatal outcome. It added that the benefits from the vaccine continued to outweigh the risks for people receiving it as it was effective in preventing Covid-19 and reducing hospitalisations and deaths.
EMA has also started reviewing AEFI reports of capillary leak syndrome (when blood plasma leaks through the walls of capillaries) after five cases were reported.
The EMA concluded by stating that national authorities could provide additional guidance on the rollout of the vaccine based on the situation in the respective countries. However, till now, no authority in India has issued any guideline on the management of specific AEFI. The only available document is a generic one on Covid vaccination, which includes a section on AEFI management. The document was last updated on December 28, 2020, well before vaccination was started in India.