11 July 2024

Thanks to constant mutations, the COVID-19 virus is still several steps ahead of vaccine developers. While researchers have managed to develop vaccines that are effective against the original strain of the new coronavirus and major variants like Delta, global mass vaccination efforts have failed to halt the raging pandemic.

This is because the virus continues to evolve, spawning new mutations that evade the defences of currently available vaccines.

As a result, the global infection rate remains at nearly one million confirmed COVID-19 cases per day, with thousands of deaths. Since the pandemic began, COVID-19 has claimed some 6.45 million lives across the world.

Hope for a new vaccine?

Earlier this week, the United Kingdom became the first country to approve a next-generation booster, Moderna’s mRNA-1273.214, for general use. The UK expects to start distributing this new vaccine before the end of the year.

This bivalent mRNA jab was developed to trigger an immune response against both the original 2020 virus and mutants like Alpha, Beta, Delta and Gamma, as well as the Omicron subvariant BA.1, which was first detected late last year.

Though this vaccine provides protection against most strains of COVID-19 and Omicron BA.1, it does not specifically target the more contagious BA.4/5 subvariants that are now dominant in Thailand and across the world.

Hence, this next-generation vaccine has not been approved by the United States, which wants a modified booster that contains the genetic code for the Omicron BA.4/5 spike protein to provide extra protection.

The US demand shows that vaccine developers are struggling to keep up with pace of COVID-19 mutations.

“Adding the BA.4/5 spike protein to the vaccine may take another six months. What if new subvariants emerge during that period?” asked Dr Nakorn Premsri, who leads Thailand’s National Vaccine Institute (NVI).

Nakorn points out that Omicron may not be the last variant of COVID-19 that spreads across the world.

COVID infections on the rise in 44 provinces, over 30,000 new cases a day

What are Thailand’s plans?

Nakorn said his institute is funding the development of various vaccine prototypes in Thailand despite there being no guarantee that the new formulations will be potent against the constantly mutating virus.

“We must take all necessary steps and precautions,” he said.

Nakorn said Thailand’s National Center for Genetic Engineering and Biotechnology (BIOTEC) has started developing a viral-vector vaccine to combat BA.4/5 subvariants. Meanwhile, a team at Chulalongkorn University is developing an mRNA prototype that targets Omicron.

He added that NVI is also closely monitoring developments overseas to ensure Thailand does not miss out on anything.

The Pfizer-BioNTech (Comirnaty) and Novavax vaccines are also in the process of being updated to target Omicron BA.1. Their development has already entered Phase 3 of clinical trials.

Advice for the Thai public

While Thailand does not yet have a next-gen vaccine, NVI deputy director Dr Sunate Chuenkitmongkol believes that the options currently available are good enough.

“They may not be the best, but they are effective enough in preventing severe symptoms, hospitalization and death,” she said.

Dr Piyanit Tharmaphornpilas, a specialist at the Disease Control Department (DCD), said a third jab is now a must for people whose health condition allows them to be vaccinated.

“If you got your second jab more than four months ago, please go and get your booster,” she urged.

More than 53 million people in Thailand have already received their first two shots against COVID-19, but only 26.12 million have agreed to take their third shot. COVID-19 vaccines are widely available now and booking one is far easier than it was last year.

The Public Health Ministry is calling on people to take a COVID-19 booster shot every three or four months in a bid to lower fatalities. Of the 29 people who succumbed to the virus on August 16 alone, 28 were elderly or had underlying health conditions, and none had received a booster shot over the past three months.

According to DCD, vaccination saved more than 490,000 lives in Thailand between February 28 last year and July 3 this year.

By Thai PBS World’s General Desk

COVID still a killer for 500,000 vulnerable people – but Thailand has new defense