Vaccines are one of humanity’s greatest achievements. Since 1974, they have prevented 154 million deaths – averaging over three million each year, or six every minute for 50 years.

These statistics were shared by the World Health Organisation (WHO) ahead of World Immunisation Week, which starts on Thursday and ends on April 30.

According to WHO, widespread immunisation has also ‘driven down infant mortality by 40%’. It says the measles vaccine accounts for 60% of these saved lives.

Caxton Network News spoke to the National Institute for Communicable Diseases (NICD) and Prof Shabir A Madhi, the dean of the Faculty of Health Sciences at the University of the Witwatersrand and director of the Vaccines and Infectious Diseases Analytics Research Unit (Wits-VIDA), to find out more about immunisation in South Africa.

Vaccines defeat deadly diseases

It is thanks to vaccines and ongoing research and development that diseases once considered deadly are now controlled.

When South Africa added the rotavirus vaccine to the national childhood immunisation programme in August 2009, there was a ‘massive decrease in hospitalisation for gastroenteritis’, says Madhi.

A significant example of the power of vaccines is the eradication of smallpox, a severe disease that had been around for centuries and caused painful illness, with ‘up to 45% mortality in severe cases’, says the NICD.

The NICD explains that in 1796, Dr Edward Jenner noticed that milkmaids who had had cowpox did not develop smallpox. He took material from a cowpox sore and inoculated it into the arm of a young boy. Although the boy was regularly exposed to smallpox, he never developed the disease. This groundbreaking experiment led to the development of the smallpox vaccine and, eventually, to the eradication of the disease. The last known case occurred in 1977.

Then there is polio. A major outbreak in the United States left 2 000 people dead in 1916. Thirty-six years later, another outbreak claimed 3 000 lives. The NICD says thousands of children were paralysed, had deformed limbs and required interventions to help them breathe, including iron lungs, a coffin-like cabinet respirator.

The development of two vaccines in 1955 and 1961, respectively – by Jonas Salk (injectable inactivated polio vaccine) and Albert Sabin (a weakened live virus given orally) – kickstarted a nationwide immunisation campaign in the United States. Both Salk and Sabin initially tested the vaccines on themselves.

In South Africa, polio epidemics occurred in the 1940s. In 1948, the Polio Research Foundation (PRF) was established, and South Africa became one of the first countries in the world to widely administer the Salk vaccine.

The NICD says the Salk vaccine was made at the PRF (in parallel with the US).

Could polio make a comeback?

“Global vaccination efforts have almost eradicated this disease, with only two countries having wild-type poliovirus,” says the NICD. They are Pakistan and Afghanistan. “Areas of war and strife where vaccinations are not given and areas where vaccination coverage remains poor can cause polio to become a threat again.”

Vaccine myths

There are many vaccine sceptics around, especially since Covid-19. The spread of vaccine mis- and disinformation promotes vaccine hesitancy, and this was worsened by the anti-vaxx movement that became prevalent during the epidemic.

Madhi cites the current measles outbreak in the United States as a ‘good example of why we cannot be complacent about immunising our children’.

In 2000, measles was declared eliminated in the country, largely due to the effectiveness of the MMR vaccine and widespread vaccination coverage. However, there has been a resurgence of the disease in the United States, which has already recorded more than 700 cases of measles this year, including two fatalities – a hefty increase from the 285 cases in 2024.

Madhi and the NICD unpack several vaccine myths:

Myth: Vaccines weaken the immune system.

Madhi: Vaccines prepare the immune system to control the infection when a person is exposed to a virus or bacteria.

Myth: The measles (or any vaccine) causes autism.

Madhi: The doctor responsible for fabricating the data used to spread this misinformation was deregistered in the UK.

NICD: The study linking autism to the measles vaccine was flawed, disproved and retracted, and many newer studies have shown no relationship between autism and vaccines.

Myth: It is better to get immunity from infection than from a vaccine.

Madhi: Use that strategy if you are willing to gamble on the health and life of your child.

Myth: Getting a vaccine will make me/my child sick.

NICD: Vaccines can make you/your child slightly ill, but these symptoms are usually mild and do not last long.

Myth: Vaccines contain pork products, and my belief/culture doesn’t allow me to have porcine products.

NICD: Few vaccines use porcine gelatine as a stabiliser, and none of these are in South Africa’s expanded programme on immunisation.

Myth: If you missed a vaccine, it is too late to catch up.

NICD: This is not true. A catch-up immunisation schedule is available and used by healthcare workers to help people get up to date on their vaccines safely and effectively.

FAQs

Where are vaccines available, and are there any costs involved?

NICD: Key vaccines that are on the public sector’s expanded programme on immunisation schedule are free at community clinics.

Madhi: Some GPs, pharmacies and private hospitals also provide vaccines, although costs may vary and could include the costs of the vaccines and their administration.

Which vaccinations are important for adults in South Africa, especially those in high-risk groups (such as the elderly and immunocompromised)?

NICD: Flu, Covid, pneumococcal conjugate vaccine (highest valency that is available) and the combination tetanus, diphtheria and acellular pertussis vaccine.

How does the immune system respond to vaccines, and how does this protect us from disease?

NICD: Vaccines contain harmless parts of a virus or bacteria. When we get a vaccine, antigens from the weakened pathogen (virus or bacterium) or tiny bits of the pathogen can trigger the immune cells to fight off these foreign substances and protect the body from disease. The immune response also produces ‘memory cells’ that remember what the foreign substance or invader looks like, so when the real bacterium or virus attacks, the immune system is ready to fight it off.

How did Covid affect vaccinations, and what were the consequences?

NICD: The epidemic negatively impacted the coverage of routine vaccines. This is because during the lockdowns, health services were disrupted and children couldn’t access vaccination. This means that we have an immunity gap that is likely contributing to outbreaks of vaccine-preventable diseases such as diphtheria and measles. Children who have missed any vaccine doses must be taken to the clinic to catch up on those missed doses to ensure that they are protected against all the vaccine-preventable diseases.

How does widespread vaccination protect not just individuals, but entire populations?

 Madhi: Widespread vaccination protects individuals who may not be able to be vaccinated because of medical conditions. As an example, children who are immunocompromised should not get some live attenuated vaccines such as measles or oral polio. However, if a sufficient percentage of the childhood population is vaccinated, vaccination can interrupt transmission of the virus in the community, and even children who have not been vaccinated will be protected from being infected.

Public healthcare’s vaccine schedule

The NICD says a hepatitis B vaccine is now given at birth to babies whose mothers tested positive during pregnancy for the hepatitis B surface antigen. In addition, the rubella vaccine (at six months and 12 months) has been added to the measles vaccine as a combination dose.

Here is the schedule:

• Birth: (BCG, Oral polio vaccine and Hepatitis B vaccine at birth for those babies whose mothers tested HBsAg positive during pregnancy).
• Six,10 and 14 weeks: Hexaxim (6-in-1 vaccine for diphtheria, tetanus, acellular pertussis, inactivated polio, haemophilus influenzae type b, hepatitis B).
• Also at six and 14 weeks: Pneumococcal conjugate vaccine (PCV) and rotavirus vaccine (RV).
• Six months: Measles, rubella vaccine.
• Nine months: PCV.
• 12 months: Measles, rubella vaccine (MR).
• 18 months: Hexaxim.
• Six years: Tetanus, diphtheria, acellular pertussis (TdaP).
• 12 years: TdaP.

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