In Vietnam, the first Covid-19 case was recorded on 23/1/2020. The disease then spread to many provinces and cities, with over 11.6 million cases and 43,206 deaths. Numerous field hospitals were established to promptly respond to and treat the rapidly increasing number of cases. Photo of a field hospital in Vung Tau. Photo: Dang Khoa

Covid-19

In late December 2019, multiple cases of unusual pneumonia emerged in Wuhan City, Hubei Province, China. The disease subsequently spread to over 231 countries and territories, resulting in over 777 million positive cases and nearly 7 million deaths by 25/5/2025. The Huanan Seafood Wholesale Market in Wuhan, Hubei Province, recorded the first Covid-19 case.

Photo of a Covid-19 testing site at Incheon International Airport, Seoul, South Korea. Photo: AFP

In 1998, the WHO adopted a resolution to eliminate neonatal tetanus globally by 2000 through three strategies, including tetanus vaccination for mothers. A health worker in Nepal prepares to administer a tetanus vaccine to a child. Photo: UNICEF/US CDC

With the rapid spread and complications of Covid-19, the rapid production and deployment of vaccines was crucial. On 11/1/2020, the gene sequence of the SARS-CoV-2 virus was published. Nearly 11 months later, the first vaccine, produced by Pfizer and BioNTech, was released, followed by vaccines from Moderna, AstraZeneca, and Johnson & Johnson.

Clinical trials with over 44,000 participants for the Pfizer and BioNTech vaccine showed it to be over 95% effective without serious side effects. These vaccines were then widely distributed to countries around the world, with Vietnam achieving one of the highest Covid-19 vaccination coverage rates globally. On 5/5/2023, the WHO declared that Covid-19 was no longer a global health emergency. Photo: Pham Chieu

Smallpox

Smallpox, caused by the variola major and variola minor virus strains, causes symptoms including fever, rash, and red bumps all over the skin. Before its complete eradication through vaccination, the disease had a mortality rate of approximately 30%, killing 300 million people in the 20th century alone. An artist depicted a treatment area for smallpox patients at Hampstead Smallpox Hospital, England, on 7/10/1871, to illustrate the context of the epidemic. Photo: Wikimedia Commons

Before the vaccine, smallpox was considered a grave danger to the community. Those who survived often suffered from complications and carried scars for life.

One of the largest outbreaks occurred in April 1520 in the US and Mexico. Due to a lack of immunity, nearly 90% of the population in the northern and southern Caribbean died from the disease. In Europe, smallpox is estimated to have killed 60 million people in the 18th century alone.

By 1980, following a global smallpox vaccination campaign launched by the WHO, smallpox was completely eradicated. The vaccine also paved the way for the development of other vaccines against infectious diseases. Photo: AP

Polio

The polio virus typically resides in the throat or intestines and is easily transmitted through the fecal-oral route or through contaminated objects. Children under 5 are particularly vulnerable. Once inside the body, the virus attacks the central nervous system, weakening muscles, causing acute flaccid paralysis, and leading to death. This image depicts children with limb deformities after contracting polio in the 20th century. Photo: polioeradicationorg

The first polio outbreak in Vermont, USA, in 1894, saw 132 cases. The disease recurred every few years, plaguing communities for decades with no effective solution. During the 1950 outbreak, amidst the difficult choice of prioritizing critical patients or those with a higher chance of survival, doctors realized that prevention through vaccination was the only way forward.

Following vaccination campaigns that gradually reduced the number of cases, the WHO launched a global polio eradication program in 1988. Vietnam was declared polio-free by the WHO in 2000 thanks to achieving over 95% polio vaccine coverage through the Expanded Program on Immunization.

A computer-generated image of enterovirus D68, which was warned to potentially cause polio in children. Photo: Med Page Today

Japanese Encephalitis

Japanese encephalitis virus is transmitted through the blood. The Culex mosquito acts as a vector, transmitting the disease to humans through bites after feeding on infected birds and livestock such as pigs, buffalo, cows, and horses. After an incubation period of about a week, the virus causes fever, headache, followed by drowsiness, muscle stiffness, convulsions, and coma as it attacks the brain's blood vessels, with a mortality rate of up to 30%. Photo: Vecteezy

The first case of Japanese encephalitis was recorded in 1871 in Japan, which experienced its first major outbreak in 1924, with over 6,000 cases and 3,000 deaths within 6 weeks. A more recent outbreak occurred in 2005 in India and Nepal, with 5,000 cases and 1,300 deaths. The disease then spread to 24 countries in Asia, putting over 3 billion people at risk.

According to the WHO, the Japanese encephalitis vaccine is safe and effective, preventing 90% of cases. Thanks to the vaccine, the disease has been controlled, and infection rates have significantly decreased.

In Vietnam, vaccines produced by Vietnam, India, and France are available through the Expanded Program on Immunization and private healthcare services. Due to widespread vaccination, recent cases in Vietnam have primarily been among those unvaccinated or those who haven't received booster shots. Photo: Le Nga

Tetanus

In the 1980s, neonatal tetanus was a life-threatening disease for newborns, with a mortality rate of nearly 100%. The WHO estimated that approximately 800,000 newborns died each year from tetanus, meaning about 6-7 deaths per 1,000 births. The disease infects newborns during birth in unsanitary conditions, when unsterilized medical instruments are used to cut the umbilical cord or in cases of infection near the navel.

A newborn with tetanus experiencing muscle stiffness in 1995, as the mother had not been vaccinated against the disease. Photo: US CDC

According to the WHO, vaccinating mothers has helped over 80% of newborns avoid tetanus. In 2013, around 49,000 newborns died from neonatal tetanus, a 94% decrease compared to the late 1980s. By May 2016, over 140 million women of childbearing age had received two doses of the tetanus vaccine. Vietnam was declared free of neonatal tetanus in 2005, thanks to widespread vaccination coverage.

A pregnant woman in her fourth month receives a diphtheria-pertussis-tetanus vaccine at the VNVC Vaccination System. Photo: Dieu Thuan

Cong Nguyen