AZ vaccine link to blood clots not confirmed, WHO says

(Third Anne Peralta-Malonzo)

A COMMITTEE of the World Health Organization (WHO) said the link between the AstraZeneca (AZ) vaccine and the rare cases of blood clots with low platelets is “considered plausible but is not confirmed.”

“Specialized studies are needed to fully understand the potential relationship between vaccination and possible risk factors,” the Covid-19 subcommittee of the WHO Global Advisory Committee on Vaccine Safety (GACVS) said after reviewing the reports on April 7.

Although the reports are concerning, the committee noted that the cases are very rare compared to the almost 200 million individuals who have been inoculated with the AZ vaccine against coronavirus disease 2019 (Covid-19).

“Rare adverse events following immunizations should be assessed against the risk of deaths from Covid-19 disease and the potential of the vaccines to prevent infections and reduce deaths due to diseases,” the WHO said in a statement.

“In this context, it should be noted that as of today (April 8, 2021), at least 2.6 million people have died of Covid-19 disease worldwide,” it added.

The committee noted that majority of the side effects from the AZ vaccine, which occur within two or three days following vaccination, are mild and local in nature. These are also expected and common.

Individuals who experience any severe symptoms from around four to 20 days following vaccination should seek urgent medical attention.

Severe symptoms include shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms like severe and persistent headaches or blurred vision, and tiny blood spots under the skin beyond the site of the injection.

“Clinicians should be aware of relevant case definitions and clinical guidance for patients presenting thrombosis and thrombocytopaenia following COVID-19 vaccination,” the committee said.

The subcommittee also suggested that a committee of clinical experts, including haematologists and other specialists, is convened, for advice on clinical diagnosis and case management.

Vaccination sites should actively monitor those who received the AZ vaccine, it added.

“Vaccines, like all medicines, can have side effects. The administration of vaccines is based on a risk versus benefit analysis,” the WHO said.

During its meeting on April 7, the subcommittee reviewed the latest information from the European Medicines Agency, and Medicines and other Health Products Regulatory Agency of the United Kingdom, among others.

The Philippines has halted vaccinations using the AZ vaccine for adults under 60 years old because of the reports of blood clots. Health authorities, at the same time, said the 525,600 doses of AZ vaccine donated through the Covax facilities have been used up. (SunStar Philippines from PR)


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