Explainer: Is China’s Sinovac coronavirus vaccine less effective?

On Wednesday, Pakistan received 0.5 million doses of the Sinovac coronavirus vaccine, orders for which were placed earlier in the year.

Sinovac is the third Chinese coronavirus vaccine to be granted approval for emergency use in Pakistan, after the Sinopharm and CanSino vaccines.

What do we know about Sinovac?

The coronavirus vaccine CoronaVac has been developed by a Beijing-based biopharmaceutical company named Sinovac.

Read more: 500,000 SinoVac coronavirus vaccine doses arrive in Pakistan

This two-dose shot went through phase III, therefore human trials, in seven countries, including Turkey, Brazil and Indonesia.

One advantage of this drug is that unlike Pfizer and Moderna, the Sinovac COVID-19 vaccine can be stored in a standard refrigerator at 2-8 degrees Celsius.

How effective is the Sinovac vaccine against coronavirus?

During clinical trials in Brazil, the Sinovac vaccine was initially declared 78% effective against the virus. Later, that figure was revised down to 50.4%.

But Fiona Russel from the Murdoch Children’s Research Institute in Melbourne told Bloomberg in an interview that Sinovac’s lower efficacy should not be a concern.

Coronavirus: Pakistan okays emergency use of third Chinese vaccine

She said that efficacy data of about 50% was for very mild disease, requiring no treatment, while for infections requiring some medical intervention, it’s about 84% and for moderate-to-severe COVID-19 cases, it’s 100%.

“That’s what you expect from coronavirus vaccines -- higher efficacy against more severe infections and lower against milder ones. From what I can see, it looks like a very worthwhile vaccine,” she added.

Sinovac’s jab has to date been approved in 22 countries, as per the COVID-19 vaccine tracker, including Pakistan, Turkey, Brazil, Hong Kong and Indonesia.