KUALA LUMPUR: Cases of heart attacks, strokes, and blood clots that are still occurring now have no connection to the AstraZeneca vaccine, says Tan Sri Dr Noor Hisham Abdullah.
The former health director-general said this was because there has been no recent vaccination programme using the AstraZeneca vaccine and it was also not used for booster doses.
He advised the public to not worry about the ongoing court case in the United Kingdom where AstraZeneca had allegedly confirmed that the vaccine could lead to rare blood clotting side effect as the cases had occured at the height of the pandemic.
"The side effects said to be associated with the AstraZeneca vaccine include blood clotting or Vaccine Induced Immune Thrombotic Thrombocytopenia (VITT).
"It is a condition where blood clots together with a decrease in platelet count. This only occurs within a timeframe of four days to four weeks after vaccination.
"The public is advised not to worry because the last AstraZeneca vaccination was given years ago. The court case being publicised is related to an incident that occurred in the United Kingdom during the Covid-19 pandemic and is not based on recent events," he said in a posting on X today.
He said the current occurrences of heart attacks, strokes, and blood clotting problems are due to other risk factors such as smoking, cholesterol problems, and diabetes.
He called on the public to differentiate between the side effect involving VITT and other blood clotting problems.
"The diagnostic criteria for VITT must include it occurring within four weeks after vaccination and a low platelet count.
"Diagnosis cannot be made visually without examination and confirmation by medical officers. We need to be cautious with fact analysis and misinterpretations that could cause confusion among the public," he said.
Noor Hisham said when the Health Ministry was deciding on the types of vaccine, they had received the reports that VITT could occur within four days to four weeks after vaccination.
However, he said, the vaccine was still necessary for the vaccination programme because the death rate from Covid-19 among the unvaccinated population was very high, and vaccine supplies were insufficient.
Hence, he said, those who were deemed high-risk including those with a history of blood clots were not allowed to receive the AstraZeneca vaccine.
"The Health Ministry had also issued guidelines to screen high-risk individuals from receiving this type of vaccine and for early detection of these side effects including AEFI (adverse events following immunisation)," he said.
Aside from these precautions, he said cases of VITT were very low, standing at four cases per one million injections.
"When compared to the risk of blood clots and low platelets after a Covid-19 infection itself, the vaccine was safer.
"After a Covid-19 infection, the risk of thrombotic thrombocytopenia (TT) is as high as 165,000 cases per one million infections. The incidence of blood clots among smokers is higher, nearly 1,800 cases per one million smokers.
"No more VITT cases have been detected and reported now," he said.