Top virologist warns of vaccine limitations against South African, Brazilian variants

A prominent Thai virologist says Thailand must prevent the arrival of the South African (also known as 20H/501Y.V2, B.1.351 lineage) or Brazilian Covid-19 (B.1.1.248) variants, warning that vaccines are not fully effective against those strains, or at least there is not enough conclusive information about their efficacy against the new variants at this stage.

Yong Poovorawan from Bangkok’s Chulalongkorn University was addressing a press conference at the Public Health Ministry when he issued the warning.

“We have to be cautious about which novel variants are being imported into our country.”

Yong says the surfaces of the variants carry different protein spikes to those found in the original strain of the virus. This means the virus takes on a different shape, making it more difficult for the human immune system to recognise it.

The Bangkok Post reports that Yong has suggested improved quarantine to keep variants out, but admits this is not fool-proof, given the recent arrival of the UK, or B.1.1.7, variant. He is also calling on the public not to be so concerned about which vaccine they are offered, insisting all the vaccines have been proven safe and effective at reducing serious illness (with very few side effects).

“We can be assured about the quality and efficacy of the vaccines, including those that we have here in Thailand.”

However, over the weekend, a prominent disease control expert in China admitted that their country’s Covid-19 vaccines have “low” effectiveness. There is speculation the country plans to produce mRNA-based vaccines, similar to those manufactured by Pfizer and Moderna, which China has previously tried to discredit.

The overall efficacy of the Sinovac vaccine, the most well-known of the four developed in China, was found to be as low as 50.4% during late stage trials in Brazil although the performance was better in Indonesia and Turkey.

SOURCE: Bangkok Post