LETTER | Data shows Sinovac, Pfizer vaccines equally effective against infection

Dr Ong Hean Teik

Modified 18 Jul 2021, 4:18 pm

LETTER | The reported statement by the former health minister on Sinovac effectiveness contains several factual errors that need correction because such misconceptions can hinder the vaccination programme of our country.

Contrary to what he says, there is very good published medical data on the actual effectiveness of Sinovac used in the real-world setting. On July 7, the New England Journal of Medicine published a report on the Sinovac experience in Chile from February to May 2021 looking at 4.2 million fully vaccinated people compared to 5.5 million unvaccinated residents. 

Sinovac was found to reduce Covid-19 infection by 65.9 percent , reduce hospitalisation by 87.5 percent, reduce ICU admission by 90.3 percent and reduce deaths by 86.3 percent.

Israel Health Ministry has also pointed out recently that the effectiveness of the Pfizer vaccine against Covid-19 infection was 64 percent, although it was still 93 percent effective against hospitalisation and serious illness.

Therefore there is not much difference between the Sinovac and Pfizer vaccines in actual practical use. Both are very effective at preventing severe disease and hospitalisation, but less effective against mild or asymptomatic Covid-19.

The government’s temporary suspension of Sinovac use has nothing to do with vaccine efficacy but is a matter of logistics. 

After ordering and receiving 32 million doses of Sinovac, almost 16 million doses have been given, meaning that the remaining 16 million doses have to be reserved as the second dose for those who have already received their first Sinovac injection. 

Meanwhile, Pfizer stocks have not been used up so quickly, and it is only natural and logical to use up the Pfizer vaccine for those who are coming in for the first vaccination dose. 

This point has been clarified by both Science, Technology and Innovation Minister Khairy Jamaluddin and Pharmaniaga. 

Sinovac will still be available at private healthcare centres for those wishing to use it, clearly showing that the Health Ministry is happy with its efficacy and continued use. 

It is important not to confuse a logistical issue with vaccine efficacy since such misunderstanding can hinder efforts to encourage people to come in for vaccination.

In conclusion, the medical literature shows clearly that both Sinovac and Pfizer are very effective against serious Covid-19, but are less effective at preventing mild disease. 

This point is important to rally the public to maintain SOPs even after vaccination. 

Those vaccinated can still catch mild or asymptomatic Covid-19 and transmit the disease to others, so social distancing and SOP must be continued to combat Covid-19 spread.

The views expressed here are those of the author/contributor and do not necessarily represent the views of Malaysiakini.