WHO defends AstraZeneca vaccine amid concerns over blood clots

Preliminary investigations into the safety of the Oxford AstraZeneca vaccine have revealed that there is no link between the blood-clotting reports and the vaccine.

The findings by the World Health Organization (WHO) coming after a dozen countries in Europe reported a number of people with blood clotting-related issues after inoculation.

Oxford AstraZeneca was among other COVID-19 developed vaccines meant to cough to life the staggered economies of countries around the world following a rather harsh year graced by the effects of what was a new virus.

But over the recent weeks, countries like Germany, France, Italy, Spain, Denmark, Norway, Austria and Ireland among others have put on hold its use.

Sweden has become the latest country to join the growing list with the country’s health ministry citing it as a precautionary measure.

In Germany, for example, 7 cases of cerebral venous thrombosis, a type of blood clot issue, were reported from about a population of about 1.6 million people who were vaccinated in the country.

Norway and Denmark had each recorded one death of persons who developed blood clots.

“So far we do not find an association between these events and the vaccine because the rates at which they have occurred in the vaccinated group are in fact less than what you would expect in the general population at the same time,” said Dr. Soumya Swaminathan, Chief Scientist, WHO.

The EU drug regulator, European Medicine Agency, in its press release dated March 15 stated that thousands of people develop blood clots annually in the EU for different reasons, but that the number of thromboembolic events overall in vaccinated people seems not to be higher than that seen in the general population.

AstraZeneca on March 14 published an update on their website stating that there have been 15 events of deep vein thrombosis and 22 events of pulmonary embolism reported among those given the vaccine based on the number of cases the company had received as of March 8 from the EU and UK.

“It is routine practice to investigate them and it shows that the surveillance system works and that effective controls are in place,” said Dr. Tedros Adhanom, Director General, WHO.

Investigations that, according to Professor Walter Jaoko – the director at the Institute of Clinical Research at the Kenya AIDS Vaccine Initiative (KAVI) – will be highly beneficial as it is not the first time in the history of vaccines that vaccination program or campaign has been halted for some reasons.

“There are some things that you might not have seen during the trial that you might start seeing after the trial. The question you ask yourself is, is it happening in a particular population group, for example? If you find that people getting clots are those with high blood pressure, you can do an advisory and say people with high blood pressure should not take vaccine yet,” said Prof. Jaoko.

And with questions arising as to whether the Oxford AstraZeneca vaccine is safe for Kenyans or not, the Kenya Medical Research Institute (KEMRI) reassures that so far in the ongoing phase three trials of the vaccine, no major side effects have been reported.

“We are talking about huge numbers of individuals that have been involved in this, there’s a very small percentage with side effects…maybe just slight headaches, loss of appetite, that over time people are able to overcome,” said Dr. Sam Kariuki, Acting KEMRI Director General.