In COVID-19 Fight, Vaccines Are Best Weapons

ADF STAFF

In any battle, it’s important to know your enemy — to recognize their appearance, their weaponry and their tactics — to mount a successful defense. The same is true of fighting COVID-19.

After the SARS-CoV2 coronavirus emerged in Wuhan, China, the world’s researchers set to work creating weapons to fight it: vaccines.

“We use a simple equation at Africa CDC: vaccines + vaccinations = lives saved,” Dr. John Nkengasong, director of the Africa Centres for Disease Control and Prevention, told Devex.

Vaccines fortify the body’s natural defenses, sharpening its ability to seek and destroy the invading virus.

COVID-19 vaccines vary in makeup. Some, like those developed by Pfizer and Moderna, use messenger RNA. Others, like the ones developed by Johnson & Johnson and AstraZeneca, use DNA.

In every case, vaccines teach the body how to identify and destroy the virus.

How Vaccines Work

The human body already has a robust, built-in disease-fighting platform called the immune system. An army of specialized cells scour the body constantly for invaders. When they find one, they tag it, destroy it and record its identity to guard against future attacks. That’s how we gain immunity.

There’s just one problem: That system requires people to get sick, potentially spread a disease and possibly die.

Vaccines give the body a harmless copy of a virus to train its immune system for battle. The result is immunity without the risk of contagion or death. Vaccinating enough people can keep disease at bay in an entire population, producing what is called herd immunity.

For COVID-19, vaccine makers rolled out new technology: messenger RNA.

In Pfizer’s and Moderna’s vaccine, a strand of mRNA teaches the immune system to identify and remember the SARS-CoV2 virus’s spike proteins — the keys the virus uses to unlock the cells where it reproduces.

The mRNA approach has been up to 95% effective for Pfizer and 94% for Moderna among those who get both doses of the two-dose vaccines.

Where Vaccines Come From

Decades of research helped scientists develop COVID-19 vaccines rapidly after the first outbreak. Johnson & Johnson, for example, used the same system it developed for the Ebola vaccine to carry the COVID-19 vaccine.

“We’re committed to not cutting corners in any way when it comes to developing a safe and effective vaccine,” Dirk Redlich of Johnson & Johnson’s Janssen Vaccines division said in September 2020. Redlich leads Janssen’s vaccine development programs.

Once they had potential vaccines, researchers put them through a series of tests to see how effective they could be against COVID-19. The early phases involved a few dozen people to see whether the vaccine was safe, to identify potential reactions and to find the dose that triggered the immune system.

By using the Ebola framework, J&J researchers moved through those early phases quickly.

Vaccines that survive early testing move to phase 3. For J&J, that involved 60,000 volunteers across three continents. Half the test subjects got the vaccine, and half got a placebo. Researchers then recorded who got COVID-19 and whether they had been vaccinated to determine the vaccine’s effectiveness.

The J&J single-shot vaccine proved to be up to 70% effective, depending on the variant. The AstraZeneca vaccine distributed by the international COVAX facility also is about 70% effective against COVID-19.

Vaccines + Vaccinations = Lives Saved

As Africa’s public health leaders push ahead with vaccinations, they face misinformation, misunderstanding and rumors. Those factors threaten to derail the Africa CDC’s goal of vaccinating 60% of the continent’s 1.3 billion people by the end of 2022.

As people hesitate to get vaccinated, vaccines reach their expiration dates and doses go to waste.

Public health leaders say countries must do more to get their citizens vaccinated, especially those most at risk of dying from COVID-19.

“The battle will be fought and won at the community level,” Nkengasong said.