Vaccines in the War Against COVID-19: Southeast Asia

Southeast Asian countries face a critical period in the war against COVID-19, as they struggle to suppress the virus. Although vaccination is not mandatory, governments in ASEAN countries strongly urge it to prevent the disease from spreading. Malaysia, Indonesia, the Philippines, and Thailand are all taking part in the vaccination campaign with the goal of reducing COVID-19 cases in their respective nations. Some ASEAN countries now shift away from Chinese vaccines out of concern for quality and lack of effectivity.

All four countries have similar vaccination program strategies. The first step is to vaccinate frontline workers, particularly those in the health sector, to protect them from catching COVID-19 and guarantee that the health system continues to function properly. The second step targets high-risk groups to reduce the burden of serious illness and comorbidity. The third step involves strategic geographic targeting, administering vaccinations in high-risk locations based on risk assessments.

Despite these similarities, Malaysia is leading the way with the highest vaccination rate amongst these countries. Malaysia’s success is partly attributed to walk-in vaccinations for persons aged 18 and above and the opening of the mega vaccination center (PPV), which has the potential to vaccinate 10,000 people each day.

COUNTRYTOTAL POPULATION 2021VACC. TARGET (% of total; number of people)FIRST DOSE (% of target; number of people)SECOND DOSE (% of target; number of people)
Malaysia32.7 million80% 26.2 million82% 21.4 million66% 17.2 million
Indonesia276 million75% 208 million35% 73.1 million20.1% 41.9 million
Philippines 109 million70% 77 million29% 22.0 million22% 16.8 million
Thailand70 million70% 49 million56% 27.3 million25% 12.4 million

Table 1. Vaccination figures as of September 13, 2021

The Variety of Vaccines Available

There’s no doubt that the type of vaccine available will have an impact not only on the vaccination rates in each country but also whether the vaccination program is effective.

Thailand, Malaysia, and Indonesia have approved 5 vaccines to be used in their country’s vaccination programs, while the Philippines has approved 8. All four countries use Pfizer-BioNTech, AstraZeneca, and Sinovac, while some vaccines are unique to each country. 


All four countries use the Pfizer-BioNTech mRNA COVID-19 vaccine, which is administered as two doses at least 21-days apart.

The vaccine is approved for adolescents aged 12 and up in Malaysia and the Philippines. In Thailand, half of the Pfizer COVID vaccine donated by the United States has been allocated for frontline medical personnel as booster shots. In June 2021, Indonesia signed a contract with Pfizer and BioNTech to obtain 50 million doses of the Pfizer vaccine by the end of the year.


All four countries approve the Sinovac inactivated vaccine, to be given in two doses. However, there are more restrictions on who can be given the vaccine, and it is primarily targeted at people who are in good general health. Pregnant mothers are advised not to have the Sinovac vaccine, and COVID-19 survivors have to wait until three months after their recovery.

Sinovac was the first COVID-19 vaccine in Indonesia to be granted an emergency use license, as well as a halal certificate. The COVID-19 vaccination program in Indonesia has been underway since January 2021, with Joko Widodo, president of the Republic of Indonesia, receiving the first vaccination.

In Thailand, Sinovac is currently approved for those aged 18-59. Thailand began vaccinating medical staff and front-liners in February 2021 using the Sinovac and AstraZeneca shots produced in the country.

Sinovac is also used in Malaysia and the Philippines with a two-dose protocol, having intervals of 2-4 weeks and 28 days in each nation, respectively. 


While all four countries use the Oxford AstraZeneca vaccine based on a viral vector, the implementation protocols in each nation differ.

In Thailand, the protocol involves two shots administered 3-4 weeks apart. However, in response to July’s spike in cases, Thailand’s National Communicable Disease Committee approved the administration of AstraZeneca as a second dose to those who got the Sinovac vaccine as first dose, despite WHO advice to the contrary.

The Malaysian authorities also recommend the Oxford-AstraZeneca vaccine to be given in two doses, with an interval of 6–12 weeks. In the Philippines, AstraZeneca is given to ages 18 years old and above with an interval of 4-12 weeks.

In Indonesia, a 12-week delay between doses is being used, citing improved efficacy. However, the daily Covid-19 vaccination rate has dropped or stalled in several provinces due to vaccine supply failing to keep up with demand. There is growing concern amongst people who have received the first dose that the delay to receive a second injection may make it ineffective.

Johnson & Johnson

The Johnson & Johnson, or Janssen, a recombinant vaccine, is a single dose vaccine approved in the Philippines, Thailand and Malaysia. In the Philippines, the senior citizens aged 60 and above and seafarers are prioritized for the Janssen vaccine.


The Moderna mRNA vaccine is approved for citizens over 18 years old in Indonesia, Philippines and Thailand, with two doses administered 28 days apart. 

Moderna is to be used as an alternative booster vaccine for private hospitals in Thailand, valid for one year starting May 13, 2021, satisfying the mRNA vaccines local demand.

In Indonesia, the Moderna COVID-19 vaccine is to be used as a third dose of vaccine for healthcare workers, as well as to members of the public who have not been vaccinated because of pregnancy or comorbidities.

Other unique vaccine brands

Certain vaccines are only approved in a few countries. Only Indonesia and the Philippines use Sinopharm, with a recommended 21-28 days interval for two doses. As for the Philippines, Sputnik V and Bharat BioTech are two of their eight approved vaccines for adults, with a 28-day and 21-42-day interval for the two doses, respectively.

However, one of the ingredients to Malaysia’s success could be the use of the CanSino Bio vaccine that only requires one dose. Rolling out these single-dose vaccines in remote areas, including islands, rural villages and oil palm estate, could speed up vaccination rates and help the country achieve 70% herd immunity by the end of the month, according to the District COVID-19 Immunization Task Force (CITF) Chairman Wong Foo Tin.

Bottom Line

As the race for herd immunity intensifies, it brings into sharp focus the limited clinical trials that current COVID-19 vaccine protocols are based on. It remains to be seen whether extended intervals between vaccine doses results in effective immunity or whether mix-and-match dosing or single doses provide adequate long-term protection.

Malaysia is well on the way to achieving their herd-immunity target on paper; yet the real impact on COVID-19 transmission rates will be something we can only assess in hindsight.