More than a year and a half into the pandemic, the more contagious Delta variant is exposing the weaknesses of nations with low vaccine rates, even if they previously had control of the virus.

Vietnam

Perhaps nowhere in Southeast Asia is that flip more evident than in Vietnam.

But since late April, Vietnam has reported a sharp increase in Covid-19 infections. On Wednesday, Vietnam reported 7,623 new cases, down from 8,620 on Sunday with most new infections in Ho Chi Minh City, the Health Ministry said. In total, Vietnam has confirmed 177,813 cases, more than 85% of those were reported in the past month alone, according to data from Johns Hopkins University. Of Vietnam's 2,327 deaths, about half were reported in the past month.

The government has imposed strict lockdowns in the capital, Hanoi, and Ho Chi Minh City to try to curb further spread and Covid treatment centers have been set up to accommodate more patients.

But the outbreak has put pressure on the government to increase its vaccine supply and ramp up inoculations. So far, only 0.6% of Vietnam's 96 million population has been fully vaccinated, according to JHU.

Indonesia

Of its 354 million reported cases since the pandemic began, 1.2 million were recorded in the past month, according to JHU. On Wednesday, Indonesia surpassed 100,000 coronavirus deaths, becoming only the second country in Asia to do so. On Wednesday, 1,747 fatalities were reported by the Health Ministry and 35,867 cases.

If the spread continues unabated, experts say it could push Indonesia's health care system to the brink of disaster. Some fear the situation may be worse than the numbers show, because not enough people are getting tested for the virus. One local survey found that nearly half of the 10.6 million residents of the capital, Jakarta, may have contracted Covid-19.

The country is suffering a health crisis, with hospitals stretched to their limits, full cemeteries expanded to hold the Covid dead, and exhausted health care workers.

Experts say Indonesia is now reaping the costs of not implementing strict lockdowns nor investing enough in efficient contact-tracing systems.

Malaysia

Despite a national lockdown, Malaysia has also seen an exponential rise in cases and deaths, with the outbreak forcing a month-long suspension of Parliament.

Anger among the people is mounting. Hundreds broke coronavirus restrictions to protest in the capital, Kuala Lumpur, over the weekend against the government's handling of the outbreak and called on Prime Minister Muhyiddin Yassin to resign. Following the suspension of a special sitting of the legislature on Monday due to Covid, opposition lawmakers marched toward the Parliament building also demanding Muhyiddin's resignation.

Frustration over the mounting deaths, vaccine rates and economic pain is exacerbated by Malaysia's current political crisis, in which Muhyiddin's government appears on the verge of collapse after taking control of the ruling coalition following elections last year.

Last week, thousands of overworked Malaysian doctors went on strike over conditions in hospitals, saying they have been pushed to the brink, as beds and ventilators run low.

The protest came as total Covid cases in Malaysia surpassed 1 million with the country reporting its highest number of daily infections. On Wednesday, Malaysia reported a new record number of cases, with 19,819 new infections, according to the Health Ministry, up from about 7,000 a month ago. Covid deaths are also at record levels, with 257 reported on Wednesday.

Malaysia's vaccine rates have improved in the past month, especially compared to its regional neighbors. About 22.5% of people in Malaysia are fully vaccinated against Covid-19, according to Our World in Data.

Thailand

Although it was the first country to report a Covid-19 case outside of China in January last year, Thailand kept its infection numbers low in 2020 thanks to successful containment measures.

This year, however, it is facing a much bigger challenge. After containing a second wave that started last December, Thailand is struggling to curb a third wave of infections that has pushed daily caseloads and death tolls to unprecedented levels. On Wednesday, Thailand reported a record high in daily confirmed cases, with 20,920 infections -- the second day of reporting over 20,000 cases, according to the Center for Covid-19 Situation Administration (CCSA). Thailand also recorded 160 deaths, bringing the total death toll to 5,663.

"We may be unable to reduce the rate of infection just yet, but we hope to ease the bed situation in Bangkok and slow down the death rate," Supat said.

On Tuesday, Thailand extended its national lockdown until the end of the month to slow the rising cases. Now, 29 provinces have been placed under the strictest protocol, meaning 40% of the country's population will be under lockdown, according to CNN's calculation of data from the CCSA.

Prolonged economic pain and fears of rising Covid fatalities are taking a toll on Thai citizens. There was public outcry after several bodies were found on the streets of Bangkok and left lying on the road for hours before an ambulance retrieved them.

And thousands of people joined anti-government protests across the country on Sunday, calling for the resignation of Prime Minister Prayut Chan-o-cha, whose government has been heavily criticized for its handling of the pandemic.

Thailand is aiming to vaccinate 50 million people by the end of the year. But according to data published by the CCSA, 23% of the country's 70 million people have received at least one dose of Covid-19 vaccine, while 5% are fully vaccinated.

Myanmar

On Thailand's border, Myanmar is collapsing under the double crisis of pandemic and military coup. There is a desperate oxygen shortage in the country, with families of the seriously ill queuing for oxygen or frantically searching online for Covid treatments.

Residents are choosing to self-treat at home, doctors say. If they do go to hospital they are often turned away as the facilities are running out of oxygen, treatments and beds, and there's not enough staff to care for patients, they said. The United Nations estimates only 40% of the country's health care facilities are still able to function.

Reported daily cases in Myanmar have risen from about 100 in early June to about 5,000 a day, with the total confirmed infections at 315,118, according to the World Health Organization. Myanmar has also reported 10,373 deaths.

Last week, Britain's UN Ambassador Barbara Woodward warned that half of Myanmar's 54 million people could be infected with Covid-19 in the next two weeks.

Adding to the trauma, those in the country say the military, which seized power in February, is wielding the Covid crisis against the people and as infections and deaths climb, the junta is escalating its attacks on doctors and health care workers, many of whom went on strike to protest the coup and have been forced into hiding to evade arrest.