19 May 2024

Thailand is strengthening its defenses against COVID-19 for about 500,000 immunocompromised people who – vaccinated or otherwise – remain vulnerable. This extra protection comes in the form of AstraZeneca’s long-acting antibody (LAAB) combination.

The antibody combination is produced by AstraZeneca under the name Evusheld. It comprises tixagevimab and cilgavimab – a combination that helps protect immunocompromised individuals from developing symptomatic COVID-19. Although the virus is seldom lethal for healthy individuals outside of at-risk groups, it has already claimed more than 6.4 million lives worldwide.

In Thailand, confirmed deaths from COVID-19 total 31,529. Most of those who succumbed to the disease had underlying health conditions that made them more vulnerable than others. Worried about these groups, the government has been seeking an extra layer of defense to keep them safe.

“We want to ensure that people with low immunity, vaccinated or otherwise, get adequate protection against COVID-19,” explained Public Health Ministry permanent-secretary Dr Kiattiphum Wongrachit. He was referring to Thailand’s procurement of about 250,000 Evusheld doses from AstraZeneca.

What is LAAB?

LAAB is an antibody combination that helps neutralize the new coronavirus that causes COVID-19, including the Omicron subvariants BA.4 and BA.5 that are dominant in Thailand, and all other variants of concern.

Also, results from the PROVENT Phase III pre-exposure prophylaxis (prevention) trial published in the New England Journal of Medicine indicate that LAAB reduces the risk of developing symptomatic COVID-19 by 77 percent in primary analysis and by 83 percent in the follow-up analysis six months later.

LAAB, also known as AZD7442, has been approved for sale in the European Union and conditionally approved in the United Kingdom for the prevention of COVID-19. It is also authorized for emergency use in the US and is being supplied to several other countries across the world.

The Thai Food and Drug Administration approved the emergency use of AZD7442 in June.

While the government has not revealed the cost of each LAAB treatment, it says that studies show this drug is cost-effective because it prevents severe symptoms or death from COVID-19.

Who is eligible?

The Public Health Ministry, which has already taken receipt of 7,000 doses of Evusheld, said priority for treatment with the new drug will go to people battling end-stage kidney disease. Also in line for LAAB treatment are patients with transplanted organs, those using immunosuppressants, cancer patients undergoing chemotherapy or radiotherapy, and others with low immunity.

To be eligible, patients must be at least 12 years old and weigh at least 40 kilos. LAAB will be administered every six months and prior to patients’ exposure to COVID-19.

There are some 500,000 immunocompromised people in Thailand, according to Deputy Government Spokesperson Traisulee Traisaranakul.

People with such low immunity, even when vaccinated, usually have weak defenses against COVID-19. So, if they are infected, they are still at significant risk of developing severe symptoms that could be fatal.

The Public Health Ministry has instructed all provincial public health offices to draw up lists of patients eligible for LAAB treatment.

The drug is given through intramuscular injections, which are administered on both sides of the buttocks, with each jab containing 1.5cc of the antibody combination.

More on the way

AstraZeneca has promised to fulfill Thailand’s order of more than a quarter of a million (257,500) doses by the end of the year.

“As we transition from pandemic to endemic, AstraZeneca remains committed to ensuring that no one in need of ongoing COVID-19 protection is left behind,” James Teague, country president of AstraZeneca (Thailand), said. “The long-acting antibody combination provides people at high risk of COVID-19 infection with another important prevention option alongside vaccination.”

There is a strong possibility that Thailand will order more LAAB doses, as people with compromised immunity are likely to require booster shots at least twice a year.

Traisulee added that the government plans to provide LAAB treatment for all 500,000 immunocompromised people in the country.

By Thai PBS World’s General Desk