WITH the government determined to ramp up the vaccination rate for Covid-19 around the country, it is now more important than ever to reassure the public about the safety and efficacy of the available doses. To aid in that task, Sirim has taken on the responsibility of testing incoming batches of Sinovac-CoronaVac (Sinovac) vaccines.
The Sinovac vaccines, which are being distributed by Pharmaniaga, will be delivered in two forms: pre-filled vials and in bulk quantities. According to Dr Ahmad Hazri Ab Rashid (pix), general manager of Industrial Biotechnology Research Centre (IBRC), Sirim, vaccines received in bulk require testing after undergoing the “filled and finished” process, where they will be filled into vials in order to be distributed to vaccination centres. The “fill and finish” process produces three batches per week.
The tests needed in Malaysia are part of the Manufacturing Process Validation, which measures criteria such as toxicity, stability, potency and microbiology of the vaccines to ensure the final product is of high quality and is safe to use.
There are three stages of process validation for vaccines, namely Stage 1 Process Design, Stage 2 Process Validation or Process Qualification, and Stage 3 Continued Process Validation. Upon approval, it would take a few more days until they can reach vaccination centres.
The tests are done by approved labs appointed by Pharmaniaga such as IBRC, Sirim, which is currently performing safety tests – Abnormal Toxicity Tests and Immunoassay (Relative Potency) and tests in animals (mice and guinea pigs). These tests will be carried out by six competent analysts and three technicians.
The tests are also governed by the USP Standards for Quality Vaccines covering 32 general and specific tests and the testing regime adopted depends on the type of vaccines.
How are the tests carried out?
The vaccines are delivered in two to three batches each week to the lab in special containers in order to preserve the temperature at 2°C to 8°C. The vaccines are then pooled and kept at room temperature for more than two hours before being injected into mice or guinea pigs.
These animal subjects will then be subjected to further testing to see the effects of the vaccines. For the abnormal toxicity test, abnormal behaviour, body weight and mortality are checked for 24 hours to seven days post-injection.
In the Immunoassay test, blood will be drawn 14 days post-injection for testing.
The ELISA kit will be used to detect the antibody titer (a measurement of how much antibody an organism has produced), and the relative potency ratio will be determined.
Animal testing has been approved within an ethical framework, and is a requirement by the National Pharmaceutical Regulatory Agency as these animals provide a biological correlation to humans, and relying on in-vitro (non animal) lab tests alone will not give an accurate reflection of vaccine efficacy or safety for human use.
Once approved, the vaccine vials will be sent for distribution to vaccination centres following strict standard operating procedures in terms of product tracking and storage temperatures.
Samples from released batches will be kept for further testing of shelf life and stability studies.
If the vaccines tested do not meet the criteria, the tests will be repeated to see whether any errors were made. Vaccine batches will not be released to the general public if there are still unresolved issues following repetitious testing.
At the moment, Sirim is testing only the Sinovac vaccine, but has also contacted companies distributing the Sputnik and Can Sino vaccine, offering its testing services if needed.
Sirim Berhad has developed the facilities and capabilities to perform a number of these tests and is continuously working with the government, other scientific testing laboratories and the pharmaceutical industry to provide comprehensive service support to ensure the country is able to undertake a vaccine development programme.
Source
No comments:
Post a Comment